Document ID: EPA-HQ-OAR-2010-0682-0993
Agency: epa
Document Type: Rule
Title: National Emission Standards for Hazardous Air Pollutants: Petroleum Refinery Sector
Posted Date: 2020-02-04T05:00Z

[Federal Register Volume 85, Number 23 (Tuesday, February 4, 2020)]
[Rules and Regulations]
[Pages 6064-6087]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 2020-01108]

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ENVIRONMENTAL PROTECTION AGENCY

40 CFR Part 63

[EPA-HQ-OAR-2010-0682; FRL 10004-55-OAR]
RIN 2016-AT18

National Emission Standards for Hazardous Air Pollutants: 
Petroleum Refinery Sector

AGENCY: Environmental Protection Agency (EPA).

ACTION: Final rule.

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SUMMARY: This action sets forth the U.S. Environmental Protection 
Agency's (EPA's) decision on aspects of the Agency's proposed 
reconsideration of the December 1, 2015, final rule: Petroleum Refinery 
Sector Residual Risk and Technology Review (RTR) and New Source 
Performance Standards (NSPS). This action also finalizes proposed 
amendments to clarify a compliance issue raised by stakeholders subject 
to the rule, to correct referencing errors, and to correct publication 
errors associated with amendments to the final rule which were 
published on November 26, 2018.

DATES: This final action is effective on February 4, 2020.

ADDRESSES: The EPA has established a docket for this action under 
Docket ID No. EPA-HQ-OAR-2010-0682. All documents in the docket are 
listed on the https://www.regulations.gov/ website. Although listed in 
the index, some information is not publicly available, (e.g., 
confidential business information or other information whose disclosure 
is restricted by statute. Certain other material, such as copyrighted 
material, is not placed on the internet, and will be publicly available 
only in hard copy form. Publicly available docket materials are 
available either electronically through https://www.regulations.gov/, 
or in hard copy at the EPA Docket Center, WJC West Building, Room 
Number 3334, 1301 Constitution Ave. NW, Washington, DC. The Public 
Reading Room is open from 8:30 a.m. to 4:30 p.m., Monday through 
Friday, excluding legal holidays. The telephone number for the EPA 
Docket Center is (202) 566-1742.

FOR FURTHER INFORMATION CONTACT: For questions about this final action, 
please contact Ms. Brenda Shine, Sector Policies and Programs Division 
(E143-01), Office of Air Quality Planning and Standards, U.S. 
Environmental Protection Agency, Research Triangle Park, North Carolina 
27711; telephone number: (919) 541-3608; fax number: (919) 541-0516; 
email address: shine.brenda@epa.gov. For information about the 
applicability of the national emission standards for hazardous air 
pollutants (NESHAP) to a particular entity, contact Ms. Maria Malave, 
Office of Enforcement and Compliance Assurance, U.S. Environmental 
Protection Agency, WJC South Building, 1200 Pennsylvania Ave. NW, 
Washington, DC 20460; telephone number: (202) 564-7027; fax number: 
(202) 564-0050; and email address: malave.maria@epa.gov.

SUPPLEMENTARY INFORMATION: Acronyms and abbreviations. A number of 
acronyms and abbreviations are used in this preamble. While this list 
may not be exhaustive, to ease the reading of this preamble and for 
reference purposes, the following terms and acronyms are defined:

AEGL acute exposure guideline level
CAA Clean Air Act
CFR Code of Federal Regulations
DCU delayed coking unit
EPA Environmental Protection Agency
ERPG emergency response planning guideline
FCCU fluid catalytic cracking unit
HAP hazardous air pollutants
ICR information collection request
lb/day pounds per day
LEL lower explosive limit
MACT maximum achievable control technology
MIR maximum individual risk
MPV miscellaneous process vent
NESHAP national emissions standards for hazardous air pollutants
NSPS new source performance standards

[[Page 6065]]

NTTAA National Technology Transfer and Advancement Act
OAQPS Office of Air Quality Planning and Standards
OECA Office of Enforcement and Compliance Assurance
OMB Office of Management and Budget
OSHA Occupational Safety and Health Administration
PB-HAP hazardous air pollutants known to be persistent and bio-
accumulative in the environment
PRA Paperwork Reduction Act
PRD pressure relief device
psig pounds per square inch gauge
PSM Process Safety Management
PTE potential to emit
RCA/CAA root cause analysis and corrective action analysis
REL reference exposure level
RFA Regulatory Flexibility Act
RMP Risk Management Plan
RTR residual risk and technology review
SRU sulfur recovery unit
[mu]g/m\3\ micrograms per cubic meter
UMRA Unfunded Mandates Reform Act
VOC volatile organic compounds
[deg]F degrees Fahrenheit

    Organization of this document. The information in this preamble is 
organized as follows:

I. General Information
    A. What is the source of authority for the reconsideration 
action?
    B. Does this action apply to me?
    C. Where can I get a copy of this document and other related 
information?
    D. Judicial Review and Administrative Reconsideration
II. Background Information
III. Final Action
    A. Issue 1: Work Practice Standard for PRDs
    B. Issue 2: Work Practice Standard for Emergency Flaring
    C. Issue 3: Assessment of Risk From the Petroleum Refinery 
Source Categories After Implementation of the PRD and Emergency 
Flaring Work Practice Standards
    D. Issue 4: Alternative Work Practice Standards for DCUs 
Employing the Water Overflow Design
    E. Issue 5: Alternative Sampling Frequency for Burden Reduction 
for Fenceline Monitoring
    F. Additional Proposed Clarifying Amendments
    G. Corrections to November 2018 Final Rule
IV. Summary of Cost, Environmental, and Economic Impacts
V. Statutory and Executive Order Reviews
    A. Executive Order 12866: Regulatory Planning and Review and 
Executive Order 13563: Improving Regulation and Regulatory Review
    B. Executive Order 13771: Reducing Regulation and Controlling 
Regulatory Costs
    C. Paperwork Reduction Act (PRA)
    D. Regulatory Flexibility Act (RFA)
    E. Unfunded Mandates Reform Act (UMRA)
    F. Executive Order 13132: Federalism
    G. Executive Order 13175: Consultation and Coordination With 
Indian Tribal Governments
    H. Executive Order 13045: Protection of Children From 
Environmental Health Risks and Safety Risks
    I. Executive Order 13211: Actions Concerning Regulations That 
Significantly Affect Energy, Supply, Distribution, or Use
    J. National Technology Transfer and Advancement Act (NTTAA)
    K. Executive Order 12898: Federal Actions To Address 
Environmental Justice in Minority Populations and Low-Income 
Populations
    L. Congressional Review Act (CRA)

I. General Information

A. What is the source of authority for the reconsideration action?

    The statutory authority for this action is provided by sections 
112, 301, and 307(d)(7)(B) of the Clean Air Act (CAA) (42 U.S.C. 7412, 
7601, and 7607(d)(7)(B)).

B. Does this action apply to me?

    Categories and entities potentially regulated by this action are 
shown in Table 1 of this preamble.

   Table 1--Industrial Source Categories Affected by This Final Action
------------------------------------------------------------------------
               NESHAP and source category                 NAICS \1\ code
------------------------------------------------------------------------
Petroleum Refining Industry............................          324110
------------------------------------------------------------------------
\1\ North American Industry Classification System.

    Table 1 of this preamble is not intended to be exhaustive, but 
rather to provide a guide for readers regarding entities likely to be 
affected by the final action for the source categories listed. To 
determine whether your facility is affected, you should examine the 
applicability criteria in the appropriate NESHAP. If you have any 
questions regarding the applicability of any aspect of these NESHAP, 
please contact the appropriate person listed in the preceding FOR 
FURTHER INFORMATION CONTACT section of this preamble.

C. Where can I get a copy of this document and other related 
information?

    The docket number for this final action regarding the sector rules 
for the Petroleum Refinery source category is Docket ID No. EPA-HQ-OAR-
2010-0682.
    In addition to being available in the docket, an electronic copy of 
this document will also be available on the internet. Following 
signature by the EPA Administrator, the EPA will post a copy of this 
final action at https://www.epa.gov/stationary-sources-air-pollution/petroleum-refinery-sector-risk-and-technology-review-and-new-source. 
Following publication in the Federal Register, the EPA will post the 
Federal Register version and key technical documents on this same 
website.

D. Judicial Review and Administrative Reconsideration

    Under CAA section 307(b)(1), judicial review of this final action 
is available only by filing a petition for review in the U.S. Court of 
Appeals for the District of Columbia Circuit (the Court) by April 6, 
2020. Under CAA section 307(d)(7)(B), only an objection to this final 
rule that was raised with reasonable specificity during the period for 
public comment can be raised during judicial review. Note, under CAA 
section 307(b)(2), the requirements established by this final rule may 
not be challenged separately in any civil or criminal proceedings 
brought by the EPA to enforce these requirements.
    This section also provides a mechanism for the EPA to reconsider 
the rule ``[i]f the person raising an objection can demonstrate to the 
Administrator that it was impracticable to raise such objection within 
[the period for public comment] or if the grounds for such objection 
arose after the period for public comment (but within the time 
specified for judicial review) and if such objection is of central 
relevance to the outcome of the rule.'' Any person seeking to make such 
a demonstration should submit a Petition for Reconsideration to the 
Office of the Administrator, U.S. EPA, Room 3000, WJC West Building, 
1200 Pennsylvania Ave. NW, Washington, DC 20460, with a copy to both 
the person(s) listed in the preceding FOR FURTHER INFORMATION CONTACT 
section, and the Associate General Counsel for the Air and Radiation 
Law Office, Office of General Counsel (Mail Code 2344A), U.S. EPA, 1200 
Pennsylvania Ave. NW, Washington, DC 20460.

II. Background Information

    The EPA promulgated NESHAP pursuant to CAA sections 112(d)(2) and 
(3) for petroleum refineries located at major sources in three separate 
rules. These standards are also referred to as maximum achievable 
control technology (MACT) standards. The first rule, promulgated on 
August 18, 1995, and codified at 40 CFR part 63, subpart CC (also 
referred to as Refinery MACT 1), regulates miscellaneous process vents, 
storage vessels, wastewater, equipment leaks, gasoline loading racks, 
marine tank vessel loading, and heat

[[Page 6066]]

exchange systems. The second rule, promulgated on April 11, 2002, and 
codified at 40 CFR part 63, subpart UUU (also referred to as Refinery 
MACT 2), regulates process vents on catalytic cracking units (CCUs, 
including fluid catalytic cracking units (FCCUs)), catalytic reforming 
units, and sulfur recovery units (SRUs). The third rule, promulgated on 
October 28, 2009, amended Refinery MACT 1 to include MACT standards for 
heat exchange systems, which were not originally addressed in Refinery 
MACT 1. This same rulemaking included updating cross-references to the 
General Provisions in 40 CFR part 63.
    The EPA conducted a residual risk and technology review (RTR) of 
Refinery MACT 1 and 2, publishing proposed amendments on June 30, 2014 
(June 2014 proposal). These proposed amendments included technical 
corrections and clarifications raised in a 2008 industry petition for 
reconsideration of NSPS for Petroleum Refineries (40 CFR part 60, 
subpart Ja). After soliciting, receiving, and addressing public 
comments, the EPA published final amendments on December 1, 2015. The 
December 2015 final rule (December 2015 rule) included a determination 
pursuant to CAA section 112(f) that the remaining risk after 
promulgation of the revised NESHAP is acceptable and that the standards 
provide an ample margin of safety to protect public health and prevent 
an adverse environmental effect. The December 2015 rule also finalized 
changes to Refinery MACT 1 and 2 pursuant to CAA section 112(d)(2) and 
(3), notably revising the requirements for flares and pressure relief 
devices (PRDs), removing startup, shutdown, and malfunction exemptions, 
and adding requirements for delayed cokers. Additional amendments were 
also promulgated pursuant to CAA section 112(d)(6) to require a 
fenceline monitoring work practice standard as an advancement in the 
way fugitive emissions are managed and mitigated. The December 2015 
rule also finalized technical corrections and clarifications to 
Refinery NSPS subparts J and Ja to address issues raised by the 
American Petroleum Institute (API) in their 2008 petition for 
reconsideration of the final NSPS Ja rule that had not been previously 
addressed. These included corrections and clarifications to provisions 
for sulfur recovery plants, performance testing, and control device 
operating parameters.
    The EPA received three separate administrative petitions for 
reconsideration of the December 2015 rule. Two petitions were jointly 
filed by the API and American Fuel and Petrochemical Manufacturers 
(AFPM). The first of these petitions was filed on January 19, 2016, and 
requested that the EPA reconsider the maintenance vent provisions in 
Refinery MACT 1 for sources constructed on or before June 30, 2014; the 
alternate startup, shutdown, or hot standby standards for FCCUs 
constructed on or before June 30, 2014, in Refinery MACT 2; the 
alternate startup and shutdown for SRUs constructed on or before June 
30, 2014, in Refinery MACT 2; and the new CRUs purging limitations in 
Refinery MACT 2. The request pertained to providing and/or clarifying 
the compliance time for these sources. Based on this request and 
additional information received, the EPA issued a proposal on February 
9, 2016 (81 FR 6814), and a final rule on July 13, 2016 (81 FR 45232), 
fully responding to the January 19, 2016, petition for reconsideration.
    The second petition from API and AFPM was filed on February 1, 
2016, and outlined a number of specific issues related to the work 
practice standards for PRDs and flares, and the alternative water 
overflow provisions for delayed coking units (DCUs), as well as a 
number of other specific issues on other aspects of the rule. The third 
petition was filed on February 1, 2016, by Earthjustice on behalf of 
Air Alliance Houston, California Communities Against Toxics, the Clean 
Air Council, the Coalition for a Safe Environment, the Community In-
Power & Development Association, the Del Amo Action Committee, the 
Environmental Integrity Project, the Louisiana Bucket Brigade, the 
Sierra Club, the Texas Environmental Justice Advocacy Services, and 
Utah Physicians for a Healthy Environment. The Earthjustice petition 
claimed that several aspects of the revisions to Refinery MACT 1 were 
not proposed, and, thus the public was precluded from commenting on 
them during the public comment period, including: (1) Work practice 
standards for PRDs and flares; (2) alternative water overflow 
provisions for DCUs; (3) reduced monitoring provisions for fenceline 
monitoring; and (4) adjustments to the risk assessment to account for 
these new work practice standards. On June 16, 2016, the EPA sent 
letters to petitioners granting reconsideration on issues where 
petitioners claimed they had not been provided an opportunity to 
comment. These petitions and letters granting reconsideration are 
available for review in the rulemaking docket (see Docket ID Item Nos. 
EPA-HQ-OAR-2010-0682-0860, EPA-HQ-OAR-2010-0682-0891, and EPA-HQ-OAR-
2010-0682-0892).
    On October 18, 2016 (81 FR 71661), the EPA proposed for public 
comment the issues for which reconsideration was granted in the June 
16, 2016, letters. The EPA solicited public comment on five issues in 
the proposal: (1) The work practice standards for PRDs; (2) the work 
practice standards for emergency flaring events; (3) the assessment of 
risk as modified based on implementation of these PRD and emergency 
flaring work practice standards; (4) the alternative work practice 
standards for DCUs employing the water overflow design; and (5) the 
provision allowing refineries to reduce the frequency of fenceline 
monitoring at sampling locations that consistently record benzene 
concentrations below 0.9 micrograms per cubic meter ([mu]g/m\3\). In 
that notice, the EPA also proposed two minor clarifying amendments to 
correct a cross referencing error and to clarify that facilities 
complying with overlapping equipment leak provisions must still comply 
with the PRD work practice standards in the December 2015 rule. We 
received public comments from 17 parties. Copies of all comments 
submitted are available at the EPA Docket Center Public Reading Room. 
Comments are also available electronically through https://www.regulations.gov/ by searching Docket ID No. EPA-HQ-OAR-2010-0682.
    In section III of this preamble, the EPA sets forth its final 
decisions on each of the five reconsideration items included in the 
October 18, 2016 (81 FR 71661), proposed notice of reconsideration 
(October 2016 proposed notice of reconsideration). Additionally, 
section III of this preamble summarizes the history of each of the five 
reconsideration items as well as the two proposed clarifying amendments 
included in the proposed notice of reconsideration, summarizes the 
public comments received on the proposed notice of reconsideration, and 
presents the EPA's responses to these comments.
    As described in section III.D of this preamble, specific to 
reconsideration item (4), the alternative work practice standards for 
DCUs employing the water overflow design, the EPA proposed and 
finalized amendments to the DCU water overflow provisions to address 
comments on the October 2016 proposed notice of reconsideration. On 
April 10, 2018 (April 2018 proposal) (83 FR 15458), the EPA proposed a 
number of technical amendments to Refinery MACT 1 and 2 and the 
Refinery NSPS, which included a proposed requirement to use a vapor 
disengaging device for

[[Page 6067]]

DCUs using the water overflow provisions. On November 26, 2018, 
(November 2018 rule) (83 FR 60696), the EPA finalized the technical 
amendments from the April 2018 proposal, including requirements for 
DCUs using the water overflow provisions, after considering public 
comments received on the April 2018 proposal.

III. Final Action

A. Issue 1: Work Practice Standard for PRDs

1. What is the history of work practice standards for PRDs?
    In the June 2014 proposal, the EPA proposed to revise Refinery MACT 
1 to establish operating and pressure release requirements that apply 
to all PRDs and to prohibit atmospheric releases of hazardous air 
pollutants (HAP) from PRDs. To ensure compliance, we proposed to 
require that sources monitor PRDs using a system that is capable of 
recording the time and duration of each pressure release and notifying 
operators that a pressure release has occurred. Many commenters 
suggested that a prohibition on atmospheric PRD releases did not 
reflect the manner in which the best performing facilities operate, was 
unachievable and/or very costly, and would have negative environmental 
impacts due to additional flares that would need to be installed and 
operated in standby mode to accept the PRD releases. Some commenters 
suggested that we should instead consider as MACT the rules on PRDs 
that apply to refineries in the South Coast Air Quality Management 
District (SCAQMD) and the Bay Area Air Quality Management District 
(BAAQMD).
    The two California district rules are similar in that they both 
establish comprehensive regulatory programs to address the group or 
system of PRDs at refineries by requiring monitoring, root cause 
analysis, and corrective action, and by applying only to those PRD with 
the greatest emissions potential through a combination of applicability 
thresholds. Based on these comments, pursuant to CAA section 112(d)(2) 
and (3), we identified the SCAQMD rule as representing the requirements 
applicable to the best performers for PRDs. Consistent with the 
requirements of the SCAQMD rule and considering additional measures 
included in the BAAQMD rule, we established work practice standards for 
PRDs in the December 2015 rule (see 40 CFR 63.648(j)(3)) for new and 
existing sources. The work practice standard is a comprehensive set of 
requirements that apply to PRDs at refineries and focuses on reducing 
the size and frequency of atmospheric releases of HAP from PRDs, with 
an emphasis on prevention, monitoring, correction, and limitations on 
the frequency of release events. For further details on our analysis of 
the SCAQMD and BAAQMD rules and our use of those rules to establish a 
work practice standard for PRDs that is representative of the 
requirements that apply at best performing refineries, refer to the 
December 1, 2015, document at 80 FR 75216-18 and the memorandum in the 
docket titled ``Pressure Relief Device Control Option Impacts for Final 
Refinery Sector Rule,'' July 30, 2015 (Docket ID Item No. EPA-HQ-OAR-
2010-0682-0750).
    The work practice standard included in the December 2015 rule is 
comprised of four parts. The first component of the work practice 
standard requires that owners or operators monitor PRDs using a system 
that is capable of recording the time and duration of each pressure 
release and notifying operators that a pressure release has occurred. 
Second, the work practice standard requires refinery owners or 
operators to establish preventative measures for each affected PRD to 
minimize the likelihood of a direct release of HAP to the atmosphere as 
a result of pressure release events. Third, in the event of an 
atmospheric release, the work practice standard requires refinery 
owners or operators to conduct a root cause analysis to determine the 
cause of a PRD release event. If the root cause was due to operator 
error or negligence, then the release would be a violation of the work 
practice standard. A second release due to the same root cause for the 
same equipment in a 3-year period would be a violation of the work 
practice standard. A third release in a 3-year period would be a 
violation of the work practice standard, regardless of the root cause--
although force majeure events, as defined in the December 2015 rule, 
would not count in determining whether there has been a second or third 
event. The fourth component of the work practice standard is a 
requirement for corrective action. For any event other than a force 
majeure event, the owner or operator would be required to conduct a 
corrective action analysis and implement corrective action. Refiners 
have 45 days to complete the root cause analysis and implement 
corrective action after the release event. The results of the root 
cause analysis and identification of the corrective action are required 
to be included in the periodic reports which are due on a semi-annual 
basis.
    Consistent with the District rules, the work practice standard does 
not apply to the following PRDs that have very low potential to emit 
(PTE) based on their type of service, size, and pressure (40 CFR 
63.648(j)(5)): PRDs that only release material that is liquid at 
standard temperature and pressure and that is hard-piped to a 
controlled drain system, PRDs that do not have a PTE of 72 pounds per 
day (lbs/day) or more of volatile organic compounds (VOC), PRDs with 
design release pressure of less than 2.5 pounds per square inch gauge 
(psig), PRDs on mobile equipment, PRDs in heavy liquid service, and 
PRDs that are designed solely to release due to liquid thermal 
expansion. These PRDs are subject to the operating and pressure release 
requirements in 40 CFR 63.648(j)(1) and (2), which apply to all PRDs, 
but not the pressure release management requirements in 40 CFR 
63.648(j)(3).
    We requested public comment on the work practice standard for PRDs 
as provided in 40 CFR 63.648(j)(3) and (5) through (7), including the 
number and type of release/event allowances; the type of PRDs subject 
to the work practice standard; and the definition of ``force majeure 
event'' in 40 CFR 63.641. We also requested public comment on the 
recordkeeping and reporting requirements associated with the work 
practice standard in 40 CFR 63.655(g)(10)(iii) and (i)(11).
    The following is a summary of the comments received in response to 
our October 2016 proposed notice of reconsideration and our responses 
to these comments.
2. What comments were received on the work practice standards for PRDs?
    Comment A.1: Some commenters were generally supportive of the final 
work practice standards for PRDs while other commenters disagreed with 
numerous aspects of the final work practice standards. The commenters 
who did not support the work practice standards claimed that they are 
unlawful because they do not provide for standards that are continuous 
and that apply at all times, pursuant to section 112 of the CAA as 
construed by the Court in the 2008 vacatur of the malfunction 
exemptions in the MACT General Provisions. Sierra Club v. EPA, 551 F.3d 
1019, 1027-28 (D.C. Cir. 2008). (``Congress has required that there 
must be continuous section 112-compliant standards.''). The commenter 
also noted that Congress in H.R. Rep. No. 95-294, at 92 (1977), 
reprinted in 1977 U.S.C.C.A.N. 1077, 1170 also provided

[[Page 6068]]

that the term ``continuous'' emission standard requirement does not 
allow merely ``temporary, periodic, or limited systems of control.'' 
The commenters believe that because the work practice standards do not 
limit emissions to an amount certain during a PRD release event, there 
is effectively no emission limitation that applies during these times. 
Additionally, commenters do not believe that the work practice 
standards are justified under CAA section 112(h) because they believe 
the EPA erred in determining that the application of measurement 
methodology was not feasible in the case of PRDs and cited available 
wireless technology or monitoring of PRD releases.
    Response A.1: We disagree that the standards do not apply at all 
times. The work practice standards for PRDs require a number of 
preventative measures that operators must undertake to prevent PRD 
release events, and the installation and operation of continuous 
monitoring device(s) to identify when a PRD release has occurred. These 
measures must be complied with at all times. The monitoring technology 
suggested by the commenters is in fact best suited to this application 
and is one of the acceptable methods that facility owners or operators 
may use to comply with the continuous monitoring requirement. Although 
that technology is adequate for identifying PRD releases, we disagree 
that it is adequate for accurately measuring emissions for purposes of 
determining compliance with a numeric emission standard. The technology 
cited is a wireless monitor that provides an indication that the PRD 
released, but it does not provide information on release quantity or 
composition. PRD release events are characterized by short, high 
pressure non-steady state conditions which make such releases difficult 
to quantitatively measure. As detailed in the preamble to the December 
2015 rule (80 FR 75218), we specifically considered the issues related 
to constructing a conveyance and quantitatively measuring PRD releases 
and concluded that these measures were not practicable. Refinery 
operators can estimate emissions based on vessel operating conditions 
(temperature and pressure) and vessel contents when a release occurs, 
but these estimates do not constitute a measurement of emissions or 
emission rate within the meaning of CAA section 112(h). As such, we 
maintain our position that the application of a work practice standard 
is appropriate for PRDs.
    Comment A.2: Commenters indicated that another reason they believe 
that the PRD work practice standard is illegal is that PRDs are not 
independent emission points and instead function in venting emissions 
from other emission points during a malfunction. For example, 
commenters pointed out that some equipment that vents to the atmosphere 
and, therefore, must meet the miscellaneous process vent standard, may 
also contain PRDs that vent HAP emissions to the atmosphere, bypassing 
the requirements established for miscellaneous process vents. The 
commenters believe that the EPA has simply created an exemption 
allowing equipment connected to PRDs to violate their emission 
standards without triggering a violation or potential enforcement and 
penalty liability. Finally, the commenters indicated that the EPA 
should retain the work practice standards for PRD on top of the 
existing emission standards for connected equipment to assure 
compliance and attempt to prevent fugitive emissions.
    Response A.2: The commenters incorrectly suggest that the PRD work 
practice standard replaces the existing emission standards for 
``connected equipment.'' The amendments to the NESHAP addressing PRDs 
do not affect requirements in the NESHAP that apply to equipment 
associated with the PRD. For example, compliance with the PRD 
requirements apply in addition to requirements for miscellaneous 
process vents for the same equipment, which addresses the commenter's 
suggestion.
    We disagree that PRDs are simply bypasses for emissions that are 
subject to emission limits and controls and that they, thus, allow for 
uncontrolled emissions without violation or penalty. The PRDs are 
generally safety devices that are used to prevent equipment failures 
that could pose a danger to the facility and facility workers. The PRD 
releases are triggered by equipment or process malfunction. As such, 
they do not occur frequently or routinely and do not have the same 
emissions or release characteristics that routine emission sources 
have, even if the PRD and the vent are on the same equipment. This is 
because conditions during a PRD release (temperature, pressure, and 
vessel contents) differ from those that occur that result in routine 
emissions as miscellaneous process vents. In contrast, emissions from 
miscellaneous process vents are predictable and must be characterized 
for emission potential and applicable control requirements prior to 
operation in the facility's notification of compliance status report. 
In addition, PRDs must operate in a closed position and, as discussed 
earlier, must be continuously monitored to identify when releases have 
occurred. If an affected pressure relief device releases to the 
atmosphere, the owner and operator is required to perform root cause 
analysis and corrective action analysis (RCA/CAA) as well as implement 
corrective actions and comply with the specified reporting 
requirements. The work practice standard also includes criteria for 
releases from affected PRD which would result in a violation at 40 CFR 
63.648(j)(3)(v).
    Comment A.3: Commenters indicated that, even if the work practice 
standards for PRDs are justified, the work practice standards do not 
comply with the CAA requirements to assure both the average limitation 
achieved by the relevant best-performing sources and the maximum degree 
of emission reduction that is achievable. The commenters asserted that 
there is no discussion in the record or analysis that allowing 1-2 
uncontrolled releases every 3 years reflects, at minimum, the average 
of the best performers' reductions and indicated that the EPA cannot 
simply replicate rules in place that specify PRD requirements. The 
commenters indicated that the EPA should have reviewed data, such as 
the 2007 SCAQMD Staff Report (Docket ID Item No. EPA-HQ-OAR-2010-0869-
0024) which shows releases from Los Angeles area refineries ranged from 
0.4-0.89 tons of VOC per year, to establish that no source has done 
better or cannot do better than those rules allow. The commenters also 
asserted that the EPA's promulgated work practice standards for PRDs 
are not as stringent as the SCAQMD and BAAQMD requirements that they 
are modelled after.
    Response A.3: Section 112 of the CAA requires MACT for existing 
sources to be no less stringent than ``the average emission limitation 
achieved by the best performing 12 percent of the existing sources (for 
which the Administrator has emissions information). . .'' [(CAA section 
112(d)(3)(A)]. ``Emission limitation'' is defined in the CAA as ``. . . 
a requirement established by the State or Administrator which limits 
the quantity, rate, or concentration of emissions of air pollutants on 
a continuous basis, including any requirement relating to operation or 
maintenance of a source to assure continuous emission reduction, and 
any design, equipment, work practice, or operational standard 
promulgated under this chapter'' [CAA section 302(k)]. The EPA 
specifically considers existing rules from state and local authorities 
in identifying the ``emission limitations'' for a given source. We then 
identify the best performers to identify the MACT floor (the no less 
stringent than level) for that source. The EPA identified the

[[Page 6069]]

SCAQMD rule requirements as the MACT floor because it represented the 
requirements applicable to the best performing sources. The commenters 
appear to suggest that the EPA should identify an emissions level 
achieved in practice through implementation of the work practices in 
the two California rules and that the EPA is obligated to require 
sources to meet that emissions level. However, this is contrary to the 
predicate for the EPA establishing work practice standards. Work 
practice standards are established in place of a numeric limit where it 
is not feasible to establish such limits. Thus, in a case such as this, 
where the EPA has determined that it is appropriate to establish work 
practice standards (because it is infeasible to establish numeric 
limits), it was reasonable for the EPA to identify the work practice 
standards that impose the most stringent requirements and, thus, 
represent what applies to the best performers and then to require those 
work practice standards as MACT.
    We recognize that the final standards for PRDs do not exactly 
mirror the SCAQMD provisions, but this is because, having established 
the MACT floor, we consider options for going beyond the MACT floor. As 
noted in the memorandum in the docket titled ``Pressure Relief Device 
Control Option Impacts for Final Refinery Sector Rule,'' July 30, 2015 
(Docket ID Item No. EPA-HQ-OAR-2010-0682-0750), we looked at the BAAQMD 
standard as a more stringent work practice standard, and while we did 
not directly adopt the BAAQMD rule requirements, we did adopt several 
aspects of that rule. Specifically, we adopted the three prevention 
measures requirements in the BAAQMD with limited modifications. We also 
did not include a provision similar to that in the SCAQMD rule that 
excludes releases less than 500 lbs/day from the requirement to perform 
a root cause analysis; that provision in the SCAQMD rule does not 
include any other obligation to reduce the number of these events. 
Rather than allowing unlimited releases less than 500 lbs/day, we 
require a root cause analysis for releases of any size. We considered 
these to be reasonable and cost-effective enhancements to the SCAQMD 
rule. However, because we count small releases that the SCAQMD rule 
does not regulate at all, we considered it reasonable to provide a 
higher number of releases prior to considering the owner or operator to 
be in violation of the work practice standard. After considering the 
PRD release event limits in both the SCAQMD and BAAQMD rules, we 
determined it was reasonable and appropriate to establish PRD 
requirements consistent with those provisions in the SCAQMD and BAAQMD 
rules that provide flare work practice standards. Therefore, the final 
requirements provide that three events from the same PRD in a 3-
calendar-year period is a violation of the work practice standard. We 
also note that a facility cannot simply choose to release pollutants 
from a PRD; any release that is caused willfully or caused by 
negligence or operator error is considered a violation. Additionally, a 
second PRD release event in a 3-calendar-year period for the same root 
cause is a violation.
    With the implementation of the three prevention measures and the 
elimination of the 500 lbs/day applicability threshold, we specifically 
evaluated and adopted requirements beyond the MACT floor (i.e., more 
stringent than the SCAQMD rule) and established requirements that we 
deemed to be cost effective and that we determined would achieve 
emission reductions equivalent to or better than the SCAQMD 
requirements.
    The EPA further notes that the reported emissions the commenters 
claim the EPA should rely on are not actually measured emissions but 
rather engineering calculations of release quantities. As such, even if 
it were possible to establish a numeric emissions limit, there would be 
concerns about relying on the information cited by the commenters. 
Finally, we note that the commenter's summary of PRD release data from 
the 2007 SCAQMD Staff Report (Docket ID Item No. EPA-HQ-OAR-2010-0869-
0024) suggests that the SCAQMD PRD requirements appear to be effective 
at reducing PRD emissions compared to states that do not have similar 
work practice standards.
    In summary, the work practice standard we finalized provides a 
comprehensive program to manage entire populations of PRDs and includes 
prevention measures, continuous monitoring, root cause analysis, and 
corrective actions, and addresses the potential for violations for 
multiple releases over a 3-year period. We followed the requirements of 
section 112 of the CAA, including CAA section 112(h), in establishing 
what work practice constituted the MACT floor; we then identified 
certain additional provisions which were more stringent than the MACT 
floor requirements that we determined were cost effective, and we 
finalized the work practice standards, as enhanced by those additional 
provisions, as MACT.
    Comment A.4: Commenters claimed that the EPA's malfunction 
exemptions are arbitrary and capricious under the CAA because the EPA 
did not finalize the prohibition on atmospheric releases from PRDs, as 
included in the June 2014 proposal. The commenters noted that the EPA 
finalized similar provisions prohibiting PRD releases in MACT standards 
for Group IV Polymers and Resins, Pesticide Active Ingredient 
Manufacturing, and Polyether Polyols Production. The commenters further 
stated that the Court recently upheld this type of prohibition 
[Mexichem Specialty Resins, Inc. v EPA, 787 F.3d 544, 560-61 (D.C. Cir. 
2015)] and urged the EPA to finalize the standards for PRD as proposed. 
The commenters also suggested that the EPA's justification for not 
finalizing a prohibition on atmospheric PRDs was based on environmental 
disbenefits of having additional flare capacity on standby to control 
these unpredictable and infrequent events. According to the commenters, 
flares can be operated with spark ignition systems that would only 
operate when triggered by a flare event, and, therefore, the commenters 
suggested that the EPA overestimated the environmental disbenefits.
    Response A.4: During the comment period on the June 2014 proposal, 
comments both from industry and environmental advocacy groups suggested 
we consider requiring the work practice standards established in 
regulations adopted by the BAAQMD and SCAQMD rules for PRD releases. In 
light of those comments and the statutory requirement that the EPA 
evaluate the best performing facilities in determining the appropriate 
MACT standard, the Agency considered whether the work practice 
standards established in the SCAQMD and BAAQMD rules represented what 
was achieved by the best performers. The BAAQMD and SCAQMD rules are 
the only rules we are aware of that have been established to address 
the infrequent and unpredictable nature of PRD releases for petroleum 
refineries. As noted in the previous response, the EPA established a 
MACT standard based on the SCAQMD rule and incorporated several of the 
key elements of the BAAQMD standard into the PRD requirements 
promulgated for new and existing sources in the December 2015 rule.
    After determining a standard based on the best performing sources, 
we examined whether to establish a more stringent standard (requiring 
all PRD releases to be routed to a control

[[Page 6070]]

device). We rejected such an approach based on the economic impacts. We 
estimated that requiring control of all atmospheric PRDs would cost 
approximately 41 million dollars per year (annually) compared to the 
estimated economic impact of the work practice standards of 3.3 million 
dollars per year. (Cost is not a consideration in setting the MACT 
floor, but it is relevant to our determination whether to establish 
additional requirements more stringent than that floor.) We also 
estimated that secondary emissions for additional flaring in the event 
all PRDs were routed to a control device would increase greenhouse gas 
emissions by 104,000 megagrams of carbon dioxide equivalents per year 
and increase nitrogen oxide emissions by 85 tons per year (see 
memorandum in the docket titled ``Pressure Relief Device Control Option 
Impacts for Final Refinery Sector Rule,'' July 30, 2015, Docket ID Item 
No. EPA-HQ-OAR-2010-0682-0750).
    Regarding the comment that flares could be equipped with spark 
ignition systems, we note that such systems are not compliant with the 
long-standing requirements in 40 CFR 60.18 and 63.11 or the new 
requirements in 40 CFR 63.670 that flares be operated with a pilot 
present at all times. The EPA has previously rejected the use of spark 
ignition systems because these systems may not reliably ignite on 
demand which would result in an atmospheric release of the pollutants 
routed to the flare.
    Comment A.5: Commenters stated that the EPA's malfunction exemption 
for force majeure events in the PRD work practice standard is arbitrary 
and capricious under CAA section 112 because it creates periods of time 
when no emissions standard applies. Further, commenters added that 
force majeure is a term defined by contracts law to provide a defense 
to avoid meeting a party's responsibility under a contract and applies 
only where a party has specifically negotiated and agreed to its use. 
As such, commenters claimed that the concept of force majeure does not 
exist or belong in the context of compliance with a non-contractual 
federal law, such as the CAA. Refineries should not be able to decide 
when to comply with the CAA requirements.
    Commenters stated that it is unlawful and arbitrary to promulgate a 
definition of force majeure that does not codify criteria for 
determining whether a force majeure event or a violation has occurred 
(i.e., the determination is left to the Administrator). The commenters 
added that the EPA does not have the authority to decide when such an 
event has occurred, rather the Court must decide whether a violation 
warranting a penalty has occurred with the burden of proof resting on 
the refinery.
    Response A.5: The PRD work practice standard requires redundant 
prevention measures, which are designed to limit the duration and 
quantity of releases from all atmospheric PRDs regardless of the cause. 
These requirements apply at all times; thus, the final work practice 
standards do have requirements that apply to PRDs at all times and they 
are not contrary to the CAA requirements in CAA section 112. We also 
note that facilities are also required to initiate a root cause 
analysis to assess the cause of the release, including releases 
determined to be caused by a force majeure event.
    We disagree that because force majeure is a term typically used in 
contract law that it cannot or should not be used in the context of 
regulations establishing standards under the CAA. We have determined 
that a force majeure provision is part of the MACT floor for regulating 
PRDs at refineries and, as such, should be included as part of the MACT 
standard. The definition of force majeure event in the December 2015 
final rule is based specifically on a clause included in the SCAQMD 
rule, which served as the basis for the MACT standard. Rather than 
repeating this clause at each instance, we determined that is was 
preferential to use and define the term force majeure event. We find 
that the December 2015 final rule's definition of force majeure event 
has adequate specificity to allow determination of whether a PRD 
release event was caused by a force majeure event. The definition 
specifies events that are beyond the control of the operator, including 
natural disasters, acts of war or terrorism, external power 
curtailments (excluding curtailments due to interruptible service 
agreements), and fire or explosions originating at near or adjoining 
facilities outside of the refinery owner or operator's control that 
impact the refinery's ability to operate. The commenters suggest that 
criteria are needed for determining whether a force majeure event has 
occurred. We disagree; the examples provided in the definition provide 
sufficient specificity to help guide a decisionmaker in deciding 
whether to pursue an enforcement action because they believe a 
violation has occurred that was not caused by a force majeure event and 
for a court or other arbiter to rule on any claim. Regarding the 
comment that the Court, not the Administrator, should determine when a 
force majeure event has occurred, we note that the regulations do not 
specify that the Administrator would make a binding determination of 
whether a force majeure event has occurred, and the issue could be 
argued and resolved by the Court in the context of a citizen suit.
    Comment A.6: One commenter supported the work practices for PRD and 
emergency flaring with the exception of the additional backstop 
measures in 40 CFR 63.648(j)(3)(iv) and (v) and 40 CFR 
63.670(o)(7)(iv), respectively. The commenter explained that these 
backstops arbitrarily limit the number of release events for PRD and 
emergency flaring events and are not needed to demonstrate continuous 
compliance with the work practice standards.
    Response A.6: For PRDs, these are the applicable standards that 
were determined to be MACT and are modeled after the backstop within 
the SCAQMD rule. With respect to the flare work practice requirements, 
our goal is to ensure continuous compliance with the emission limits 
applicable to the gas streams that are discharged to the flare. We 
determined that optimal HAP destruction occurs under specific 
conditions, which include limited periods of visible emissions. 
Therefore, we established these requirements in parallel with the PRD 
requirements to help limit the size and duration of these emergency 
flaring events and optimize flare performance. We consider these 
backstop measures for PRD and emergency flaring to be critical to 
ensure that the prevention measures implemented are effective, that the 
root-cause analyses conducted are thorough, and that the corrective 
action measures implemented are effective.
    Comment A.7: Commenters stated the final rule provided criteria for 
releases that will be considered a violation of the pressure release 
management work practices in 40 CFR 63.648(j)(v)(B) and (C) based on a 
``3 calendar year period,'' but the Agency did not explain how this 
time period runs nor how it will be assessed or reported to the EPA and 
to the public. The commenter noted that the EPA stated in the preamble 
(80 FR 75212) relative to the flare work practice provisions, the 
violation criteria is based on a ``rolling 3-year period,'' but a 
rolling 3-year period is not in the regulatory text for either the 
flare or PRD work practice.
    Response A.7: The regulatory text at 40 CFR 63.648(j)(3)(B) and (C) 
clearly states that the time period is based on a 3-calendar-year 
period. We consider 2020 to be one calendar year. A 3-calendar-year 
period in 2020 would include events that occurred in 2018, 2019, and 
2020. It is a rolling average to the extent that, in 2021, one would 
consider events that occurred in 2019,

[[Page 6071]]

2020, and 2021. As indicated in 40 CFR 63.655(g)(10)(iii), each 
pressure release to the atmosphere, including the duration of the 
release, the estimated quantity of each organic HAP released, and the 
results of the RCA/CAA completed during the reporting period must be 
included as part of the reporting obligation.
    Comment A.8: Commenters stated that the EPA should add to the 
reporting requirements for the PRD and flare work practice standards by 
requiring an initial report to the EPA, state, and local regulators 
within 1 hour of the start of a release event or within 1 hour of the 
operator reasonably knowing of its occurrence. They maintained that the 
initial report should include the process unit the flare or PRD is 
associated with and initial identification of the cause of the event. 
The initial report should be followed by a report containing the 
contents of 40 CFR 63.655(g)(10) and (11) within 30 days after the 
event and additionally include whether the PRD or flare has had an 
emissions release or smoking event in the past 3 years, including 
references or copies of previously submitted reports. Commenters added 
that this would be consistent with the Agency's attempt to match the 
SCAQMD requirements for PRDs. Finally, commenters suggested that the 
EPA should require all malfunction reports be made publicly available 
online at the same time they are submitted to the EPA.
    Response A.8: The SCAQMD rule has notification and reporting 
requirements for atmospheric PRD releases in excess of the reportable 
quantity limits in 40 CFR part 117, part 302, and part 355, including 
releases in excess of 100 pounds of VOC (Rule 1173(i)(3)). The 
notification must occur within 1 hour of the release or within 1 hour 
of the time a person should have reasonably known of its occurrence. A 
written report must be submitted within 30 days of the atmospheric 
release. These requirements closely mirror those under other EPA 
programs, such as the Superfund Amendments and Reauthorization Act 313 
(SARA 313). We note that refinery owners or operators are already 
required to report emissions events through various state and federal 
requirements, including immediate notifications of releases exceeding 
reportable quantities under SARA 313, and while we acknowledge that 
these reports would be submitted to a different branch within the EPA, 
we believe any additional reporting requirements would be redundant, 
unnecessary, and inefficient. Therefore, we are not revising the 
recordkeeping and reporting requirements in the December 2015 rule as 
requested by the commenter.
    Comment A.9: Commenters stated that the exemptions for specific 
types of pressure relief devices are unlawful and arbitrary. Commenters 
contended that the only justification the EPA has made for providing 
these PRD exemptions is that the emissions are expected to be small. 
Commenters asserted that there is no de minimis threshold for 
regulating emission points within a source category and, thus, the 
EPA's attempt to exempt certain types of PRDs is illegal.
    Response A.9: We modeled the applicability of the PRD provisions 
after the SCAQMD rule, based on a MACT floor analysis and considering 
the appropriate requirements for these types of PRDs. It is likely that 
the SCAQMD rule did not apply the PRD-specific requirements to certain 
PRDs due to their low emissions release potential. As part of our 
``beyond the floor'' analysis, we determined that it was not cost 
effective to include control of these PRDs as part of the work practice 
standard for PRDs. However, these PRDs are regulated under other 
provisions of the MACT. We note that, if the PRD is in gas or vapor 
service, refinery owners and operators are still required to monitor 
the PRD after the release to verify the device is operating with an 
instrument reading of less than 500 parts per million. Liquid PRDs are 
still subject to repair if a leak is found during visual inspection.
3. What is the EPA's final decision on the work practice standards for 
PRDs?
    The PRD work practice standards were developed in accordance with 
the CAA, establishing a MACT floor based on consideration of the SCAQMD 
and BAAQMD work practice standards. The sources complying with these 
requirements are the best performing sources. It was necessary to 
establish these requirements as work practice standards under CAA 
section 112(h) because quantitative measurement of flow rates during 
PRD release events is not practicable due to technological and economic 
limitations with measuring highly transient flows. The inclusion of 
force majeure event allowances and restrictions of the applicability of 
the pressure release management requirements to specified types of PRDs 
are consistent with the MACT floor and are necessary components of the 
work practice standards. We consider a complete prohibition of 
atmospheric PRD to be ``beyond the MACT floor'' and we are declining to 
set a ``beyond the floor'' requirement on the basis of cost and 
environmental disbenefits. We have not been presented with any comments 
and/or information received in response to the October 2016 proposed 
notice of reconsideration relative to the PRD work practice standards 
which will result in any changes to the December 2015 rule.

B. Issue 2: Work Practice Standard for Emergency Flaring

1. What is the history of work practice standards for emergency 
flaring?
    In the June 2014 proposal, the EPA proposed to amend the operating 
and monitoring requirements for petroleum refinery flares. As discussed 
in the proposal at 79 FR 36904, we determined that the requirements for 
flares in the General Provisions at 40 CFR 63.18 were not adequate to 
ensure compliance with the Refinery MACT standards. In general, at the 
time the MACT standards were promulgated, flares used as air pollution 
control devices were expected to achieve a 98-percent HAP destruction 
efficiency. However, because flows of waste gases to the flares had 
diminished based on reductions achieved by the increased use of flare 
gas recovery systems, there have been times when the waste gas to the 
flare contained insufficient heat content to adequately combust and, 
thus, a 98-percent HAP destruction efficiency was not being achieved. 
In addition, the practice of applying assist media to the flare 
(particularly steam to prevent smoking of the flare tip) had led to a 
decrease in the combustion efficiency of flares.
    To ensure that a 98-percent HAP destruction efficiency was being 
met, as contemplated at the time the MACT standard was promulgated, we 
proposed revisions to Refinery MACT 1 that required flares to operate 
with a continuously-lit pilot flame at all times when gases are sent to 
the flare, with no visible emissions except for periods not to exceed 5 
minutes during any 2 consecutive hours, and to meet flare tip velocity 
limits and combustion zone operating limits at all times when gases are 
flared.
    During the comment period on the June 2014 proposal, we received 
comments that the EPA's concern over insufficient heat content of the 
waste gas or over-assisting flares is less problematic in attaining a 
high level of destruction efficiency at the flare in emergency 
situations, where the flow in the flare exceeds the smokeless capacity 
of the flare. The commenters suggested that better combustion was 
assured closer to the incipient smoke point of the flare and that flow 
velocity limits and limits on visible emissions should not apply during 
emergency flaring events.

[[Page 6072]]

    In the December 2015 rule, we determined that it was appropriate to 
set different standards for when a flare is operating below its 
smokeless capacity and when it is operating above its smokeless 
capacity. We finalized the proposed requirements (with minor revisions) 
to apply when a flare is operating below its smokeless capacity.
    In the December 2015 rule, we established a work practice standard 
that applies to each affected flare with a potential to exceed its 
smokeless capacity. The work practice standard requires owners or 
operators to develop flare management plans to identify the flare 
system smokeless capacity and flare components, waste gas streams that 
are flared, monitoring systems and their locations, procedures that 
will be followed to limit discharges to the flare that cause the flare 
to exceed its smokeless capacity, and prevention measures implemented 
for PRDs that discharge to the flare header. The work practice standard 
requires a continuously-lit pilot flame, combustion-zone operating 
limits, and the monitoring, recordkeeping, and reporting requirements 
apply at all times--whether the flare is operating below, at, or above 
its smokeless capacity, including during a force majeure event. These 
requirements are the most critical in ensuring that a 98-percent 
destruction efficiency is being met during emergency release events.
    In addition, where a flare exceeds its smokeless capacity, a work 
practice standard requires refinery owners or operators to conduct a 
root cause analysis and take corrective action for any flaring event 
that exceeds the flare's smokeless capacity and that also exceeds the 
flare tip velocity and/or visible emissions limit. Refiners have 45 
days to complete the root cause analysis and implement corrective 
action after an event. The results of the root cause analysis and 
corrective action are due with the periodic reports on a semi-annual 
basis. If the root cause analysis indicates that the exceedance of the 
flare tip velocity and/or the visible emissions limit is caused by 
operator error or poor maintenance, the exceedance is a violation of 
the work practice standard. A second event causing an exceedance of 
either the flare tip velocity or the visible emissions limit within a 
rolling 3-year period from the same root cause on the same equipment is 
a violation of the standard. A third exceedance of the velocity or 
visible emissions limit occurring from the same flare in a rolling 3-
year period is a violation of the work practice standard, regardless of 
the root cause. However, force majeure events are excluded from the 
event count.
    We requested public comment on the above smokeless capacity work 
practice standard in 40 CFR 63.670(o), including the requirements to 
maintain records of prevention measures in 40 CFR 63.670(o)(1)(ii)(B) 
and (iv); the requirement to establish a single smokeless design 
capacity in 40 CFR 63.670(o)(1)(iii)(B); the number and type of 
releases/events that constitute a violation; the phrase ``. . . and the 
flare vent gas flow rate is less than the smokeless design capacity of 
the flare'' in 40 CFR 63.670(c) and (d); the proposed correction to 
paragraph 40 CFR 63.670(o)(1)(ii)(B); and other provisions in 40 CFR 
63.670(o)(3) through (7). We also requested public comment on the 
recordkeeping and reporting requirements associated with these work 
practice standards in 40 CFR 63.655(g)(11)(iv) and (i)(9)(x) through 
(xii).
    In reviewing the regulatory text for this proposed action, we also 
determined that 40 CFR 63.670(o)(1)(ii)(B) contains an incorrect 
reference to pressure relief devices for which preventative measures 
must be implemented. The correct reference is paragraph 40 CFR 
63.648(j)(3)(ii), not 40 CFR 63.648(j)(5). We proposed to correct this 
referencing error.
2. What comments were received on the work practice standards for 
emergency flaring?
    Comment B.1: Some commenters were generally supportive of the final 
work practice standards for emergency flares, while other commenters 
disagreed with numerous aspects of the final work practice standards. 
The commenters who disagree indicated that establishing these work 
practice standards for emergency flaring is unlawful because they do 
not provide for standards that are continuous and that apply at all 
times, as directed by section 112 of the CAA and as upheld by the Court 
in the 2008 vacatur of the malfunction exemptions in the MACT General 
Provisions. Sierra Club v. EPA, 551 F.3d 1019, 1027-28 (D.C. Cir. 2008) 
(``Congress has required that there must be continuous section 112-
compliant standards.''); see also H.R. Rep. No. 95-294, at 92 (1977), 
reprinted in 1977 U.S.C.C.A.N. 1077, 1170 (``continuous'' emission 
standard requirement does not allow merely ``temporary, periodic, or 
limited systems of control''). The commenters state that because the 
work practice standards do not limit emissions to any certain amount 
during an emergency flaring event, there is effectively no emission 
limitation that applies during these times. Additionally, the 
commenters do not believe that the work practice standards are 
justified under CAA section 112(h) for emergency flaring because 
measurement technology is available to measure what is sent to the 
flare.
    Response B.1: We disagree that the standards do not apply at all 
times. The work practice combustion efficiency standards (specifically 
limits on the net heating value in combustion zone) apply at all times, 
including during periods of emergency flaring. With respect to setting 
work practice standards under CAA section 112(h), we note that the 
combustion efficiency standards were established as work practice 
standards. In the case of flaring, emissions are not conveyed through a 
stack and are difficult to measure. The EPA's practice has been to 
establish work practice standards for regulating flares (see, e.g., 
General Provisions in 40 CFR parts 60 and 63, the combustion efficiency 
requirements in this rule, and flaring work practice standards in the 
Petroleum Refinery NSPS, subpart Ja). These work practice standards do 
take advantage of upstream measurement systems, but we do not agree 
that upstream measurement systems are the same as measuring emissions 
from the flare following combustion nor are they, standing alone, a 
sufficient emissions limitation or standard.
    Comment B.2: Commenters stated that, even if the work practice 
standards for flares operating above the smokeless capacity are 
justified, the work practice standards do not comply with the CAA 
requirements that the emissions limitation is as stringent as the 
average emission limitation achieved by the best-performing sources, 
and the maximum degree of emission reduction that is achievable. 
Commenters explained that the EPA provided an allowance for up to two 
smoking flare events per flare in a 3-year period based on API-supplied 
information reporting that the average refinery flare experiences an 
event every 4.4 years and an assumption that the best performing flares 
have one smoking event every 6 years. The commenters contended that 
these figures are based on unverified data submitted in an API/AFPM 
survey and its use is arbitrary and capricious. The commenters 
maintained that instead of using the API/AFPM survey data, the EPA 
should have reviewed data including emissions data from their own 
studies as well as emissions data available from Texas Commission on 
Environmental Quality (TCEQ), SCAQMD, or BAAQMD when developing these 
standards. The commenters suggested that the EPA

[[Page 6073]]

establish standards based on the duration and amount of gas routed to a 
flare during a malfunction event that causes the flare to operate above 
its smokeless capacity, in addition to the cap on the number of 
exceptions.
    Response B.2: First, one must recognize that the flare is not a 
specific emission source within Refinery MACT 1 standards and, thus, we 
did not seek to establish a MACT floor for flares at the time that we 
promulgated Refinery MACT 1. Rather, we identified flares as an 
acceptable means for meeting otherwise applicable requirements and we 
established flare operational standards that we believed would achieve 
a 98-percent destruction efficiency on a continual basis. Recognizing 
that flares were not achieving the 98-percent reduction efficiency in 
practice, we proposed additional requirements in the June 2014 proposal 
to ensure that flares operate as intended at the time we promulgated 
Refinery MACT 1.
    Regarding the operational standards for flares operating above the 
smokeless capacity, we note that these flare emissions are emissions 
due to a sudden increase in waste gas entering the flare, typically 
resulting from a malfunction or an emergency shutdown at one or more 
pieces of equipment that vents emissions to the flare. The commenter's 
suggestion that the EPA should establish standards on the duration and 
amount of gas discharged to a flare during malfunction events misses 
the mark. Flares are associated with a wide variety of process 
equipment and the emissions routed to a flare during a malfunction can 
vary widely based on the cause of the malfunction and the type of 
associated equipment. Thus, it is not feasible to establish a one-size-
fits-all standard on the amount of gas allowed to be routed to flares 
during a malfunction. Moreover, we note that routing emissions to the 
flare will result in less pollution than the other alternative, which 
would be to emit directly to the atmosphere. We note that we do not set 
similar limits for thermal oxidizers, baghouses, or other control 
devices that we desire to remain operational during malfunction events 
to limit pollutant emissions to the extent practicable. However, we did 
establish work practice standards that we believe will be effective in 
reducing the size and duration of flaring events that exceed the 
smokeless capacity of the flare to improve overall flare performance. 
We are establishing these work practice standards for flares in order 
to ensure 98-percent destruction of HAP discharged to the flare (as 
contemplated at the time Refinery MACT 1 was promulgated) during both 
normal operating conditions when the flare is used solely as a control 
device and malfunction releases where the flare acts both as a safety 
device and a control device.
    Comment B.3: Commenters stated that the EPA's malfunction exemption 
for force majeure events for emergency flaring is arbitrary and 
capricious under CAA section 112 because it creates periods of time 
when no emissions standard applies.
    Response B.3: As noted in Response A.5 to similar comments 
regarding PRD release events, it is very difficult to guard perfectly 
against acts of God and acts of terrorism. The EPA does not believe it 
can develop measures that would effectively limit emissions during all 
such acts. Regardless, we disagree that force majeure events are exempt 
from regulation. Several of the work practice standards apply during 
these events. Specifically, flares are required to comply with the 
requirements for a continuously lit pilot flame and combustion 
efficiency standards (i.e., limits on the net heating value in 
combustion zone) at all times, including during periods of emergency 
flaring caused by a force majeure event.
    Comment B.4: Commenters requested that the EPA delete from the rule 
the requirements at 40 CFR 63.670(o)(1)(ii)(B) and (o)(1)(iv), claiming 
the requirements are highly burdensome. These requirements require an 
owner or operator to include as part of the flare management plan (FMP) 
records of prevention measures and design and operating details for 
PRDs that are routed to flares. Alternatively, commenters recommended 
that the rule only require this information be included in the FMP for 
those PRDs (i.e., a single PRD or a single set of PRDs which protect a 
single piece of equipment) whose potential for release is great enough 
to exceed the smokeless capacity of the flare.
    Response B.4: Because PRDs are expected to be the primary source of 
a release that might cause a flaring event that could exceed the 
smokeless capacity of the flare, we determined that the identification 
of the PRDs that are vented to the flare is a critical component of the 
FMP. We also recognize that consideration of prevention measures for 
PRDs that can discharge to a flare will help to reduce the number of 
flaring events that exceed the smokeless capacity of the flare. 
Consequently, we include consideration of prevention measures for PRDs 
as one of three critical items, listed in 40 CFR 63.670(o)(1)(ii)(A) 
through (C), that each owner or operator of a flare must consider 
within the flare minimization assessment requirement of the FMP. While 
submission of the FMP is primarily a one-time event, we expect that 
these prevention measures for PRDs discharged to the flare will be an 
active and growing list as owners and operators implement corrective 
actions after a release event exceeding the smokeless capacity of the 
flare and exceeding the visible emissions limit and/or the flare tip 
velocity limit. As noted in 40 CFR 63.670(o)(2)(ii), the plan must be 
updated periodically to account for changes in the operation of the 
flare, but we do not consider new prevention measures implemented for 
PRDs that discharge to the flare to constitute a change in the 
operation of the flare. Thus, this updated listing can be in an 
electronic database and it is not required to be updated in the FMP 
unless the FMP is otherwise required to be updated or re-submitted 
according to the provisions in 40 CFR 63.670(o)(2)(ii). We do not 
consider this effort to be a significant burden beyond what is already 
required for hazards analysis and the commenter did not provide any 
data to quantify or substantiate the claims that this effort is 
``highly burdensome.''
    We considered the suggestion to limit this requirement to PRDs with 
high potential release rates. However, many flares may receive 
discharges from dozens of PRDs across multiple process units. In an 
emergency event, it is possible that several of these PRDs associated 
with different equipment can relieve at the same time. While any one 
PRD may not exceed the flare's smokeless capacity, the combination of 
PRD releases may. Thus, we determined that it is appropriate to require 
all PRDs discharged to the flare to be identified and applicable 
prevention measures should be evaluated regardless of the release 
potential of an individual PRD.
3. What is the EPA's final decision on the work practice standards for 
emergency flaring?
    The emergency flaring work practice standards were developed to 
ensure that flares achieve the 98-percent reduction assumed at the time 
MACT 1 was promulgated. In determining the means to ensure that flares 
achieve the 98-percent reduction, the EPA considered available data for 
best performing flare sources. The inclusion of the force majeure 
provisions in the work practice standard do not alter the work practice 
requirements for a continuously lit pilot flame and combustion 
efficiency standards, which apply at all times. The flare requirements 
in Refinery MACT 1 were established as work practice

[[Page 6074]]

standards and the operational standards established in the December 
2015 final rule and affirmed in this action are also work practice 
standards under CAA section 112(h). Work practice standards are 
appropriate for flares because pollutants emitted from the flare cannot 
be emitted through a conveyance designed and constructed to emit or 
capture such pollutants. We have not been presented with any comments 
and/or information received in response to the proposed notice of 
reconsideration relative to the emergency flaring work practice 
standards which will result in any changes to these requirements as 
promulgated in the December 2015 rule.

C. Issue 3: Assessment of Risk From the Petroleum Refinery Source 
Categories After Implementation of the PRD and Emergency Flaring Work 
Practice Standards

1. What is the history of the assessment of risk from the Petroleum 
Refinery source categories after implementation of the PRD and 
emergency flaring work practice standards?
    The results of our residual risk review for the Petroleum Refinery 
source categories were published in the June 2014 proposal (79 FR 36934 
through 36942), and included assessment of chronic and acute inhalation 
risk, as well as multipathway and environmental risk, to inform our 
decisions regarding acceptability and ample margin of safety. The 
results indicated that the cancer risk to the individual most exposed 
(maximum individual risk or ``MIR'') based on allowable HAP emissions 
is no greater than approximately 100-in-1 million, which is the 
presumptive limit of risk acceptability, and that the MIR based on 
actual HAP emissions is no greater than 60-in-1 million, but may be 
closer to 40-in-1 million. In addition, the maximum chronic noncancer 
target organ-specific hazard index (TOSHI) due to inhalation exposures 
was less than 1. The evaluation of acute noncancer risks, which was 
conservative, showed the potential for adverse health effects from 
acute exposures is unlikely. Based on the results of a refined site-
specific multipathway analysis, we also concluded that the cancer risk 
to the individual most exposed through ingestion is considerably less 
than 100-in-1 million.
    In the December 2015 rule, we established work practice standards 
for PRD releases and emergency flaring events, which under the June 
2014 proposal would not have been allowed. Because we did not consider 
such non-routine emissions under our risk assessment for the June 2014 
proposal, we performed a screening level analysis of risk associated 
with these emissions for the December 2015 rule as discussed in detail 
in ``Final Residual Risk Assessment for the Petroleum Refining Source 
Sector'' in Docket ID Item No. EPA-HQ-OAR-2010-0682-0800. Our analysis 
showed that HAP emissions could increase the MIR based on actual 
emissions by as much as 2-in-1 million, which is not substantially 
different than the level of risk estimated at proposal. We also 
estimated that chronic noncancer TOSHIs attributable to the additional 
exposures from non-routine flaring and PRD HAP emissions are well below 
1. When the additional chronic noncancer TOSHI from the screening 
analysis are added to the TOSHI estimated in the June 2014 proposal, 
all chronic noncancer TOSHIs remain below 1. Further, our screening 
analysis also projected that maximum acute exposure to non-routine PRD 
and flare emissions would result in a maximum hazard quotient (HQ) of 
14 from benzene emissions based on a reference exposure level (REL). An 
exceedance of an REL value does not necessarily indicate that an 
adverse health effect will occur. Because of the infrequent occurrence 
of such events and the probability that someone would be at the exact 
most highly impacted exposure locations at the time of the elevated 
ambient levels, the EPA risk assessors believe there is a very low 
probability of any adverse exposure. Based on the risk analysis 
performed for the June 2014 proposal and the screening assessment to 
consider how conclusions from that analysis would be affected by the 
additional non-routine flare and PRD emissions allowed under the 
December 2015 rule, we determined that the risk posed after 
implementation of the revisions to the MACT standards is acceptable and 
that the standards as promulgated provide an ample margin of safety to 
protect public health.
    We requested public comment on the screening analysis and the 
conclusions reached based on that analysis in conjunction with the risk 
analysis performed for the June 2014 proposal.
2. What comments were received on the assessment of risk from the 
Petroleum Refinery source categories after implementation of the PRD 
and emergency flaring work practice standards?
    Comment C.1: Commenters explained that the EPA performed a 
screening level risk assessment to account for the additional risk from 
the PRD and emergency flare work practice standards based on 
``approximately 430 records of PRD and flare HAP pollutant release 
events'' from 25 facilities, as reported in response to the detailed 
Petroleum Refinery information collection request (ICR), and that this 
assessment resulted in an additional 2-in-1 million lifetime cancer 
risk and an acute risk that is 14 times higher than what the Agency 
considers safe. The commenters contended that these risks were based on 
biased-low industry-estimated emissions data when they should have been 
based on a true maximum additional cancer or acute risk from a serious 
fire, explosion, or force majeure event, or even from one of the 
largest historical leaks or emergency flaring events. Commenters 
referenced numerous malfunction events which they asserted demonstrate 
the long history of these types of releases from refineries that could 
have been prevented by advanced planning, inspections, upgrades, and 
maintenance and claimed these events could have been used for the 
purpose of estimating additional risks from PRD releases and smoking 
flare events. In addition to not basing the risks on a worst-case 
scenario, the commenters said the EPA did not explain how the risk 
model predicted worst case 1-hour and annual average concentrations for 
PRDs and flares or whether the concentrations presented in the final 
risk assessment were total HAP or benzene. In any case, the commenters 
asserted that these concentrations are higher than what the California 
EPA has deemed health protective for acute and chronic exposure, and 
while they are lower than the EPA's 2003 Integrated Risk Information 
System values, the EPA should consider that these exposures occur in 
combination with other emissions from refineries.
    Response C.1: The December 2015 rule established work practice 
standards that require advanced planning, inspections, upgrades, and 
maintenance of equipment through the implementation of prevention 
measures, root cause analysis, and corrective action. Under CAA section 
112(f)(2), the EPA is required to estimate the risk remaining after the 
implementation of the MACT, which for this emissions source is the 
promulgated work practice standards. This approach is consistent with 
the way that EPA has performed its risk analysis for all previously 
promulgated risk reviews under CAA section 112(f)(2). In the screening 
analysis, we used release information collected under the authority of 
CAA section 114 which represents annual releases occurring prior to the 
implementation of these work practice

[[Page 6075]]

standards and the data and assumptions used as inputs to the screening 
analysis are a reasonable representation of the worst-case releases 
allowed under the promulgated standard and that may be expected 
subsequent to the implementation of the work practice standards.
    In response to the commenters' statement that the EPA did not 
explain how the risk model predicted worst case 1-hour and annual 
average concentrations for PRDs and flares or whether the 
concentrations presented in the final risk assessment were total HAP or 
benzene, as noted in the risk report (appendix 13 of Docket ID Item No. 
EPA-HQ-OAR-2010-0682-0800), the EPA estimated concentrations using a 
conservative (health protective) screening dispersion modeling 
approach. Further, the risks were estimated based on all reported 
emissions (i.e., not only benzene). Acute risks (HQs) are estimated on 
a pollutant-by-pollutant basis.
    With regard to the comment that the EPA should consider the 
California Office of Environmental Health Hazard Assessment health 
benchmarks, in May 2018, based on examination of the California EPA's 
acute (1-hour) REL for benzene, and taking into account aspects of the 
methodology used in the derivation of the value and how this assessment 
stands in comparison to the Agency for Toxic Substances and Disease 
Registry's toxicological assessment, EPA toxicologists decided it is 
not appropriate to use the benzene REL value to support the EPA's RTR 
rules. In lieu of using the REL in RTR risk assessments, the EPA is now 
evaluating acute benzene risks by comparing potential exposure levels 
to the emergency response planning guidelines (ERPG)-1 values. In this 
case, the acute HQ value from non-routine PRD and flare emissions is 
0.07 when comparing ambient levels to the ERPG-1.
    Comment C.2: Commenters asserted that the EPA's risk assessment and 
determinations are unlawful and are arbitrary and capricious because 
the EPA has not followed its own policy and guidelines in summing 
cancer risk and treating a lifetime cancer risk above 100-in-1 million 
as showing the need for section CAA section 112(f) standards. The 
commenters stated that the EPA found an inhalation-based cancer risk of 
100-in-1 million from routine emissions, an additional cancer risk of 
2-in-1 million from non-routine PRD and flare emissions, and an 
additional cancer risk of 4-in-1 million from non-inhalation or 
multipathway emissions. The sum of these risks is 106-in-1 million, 
and, therefore, above the presumptive acceptability threshold of 100-
in-1 million, yet the EPA has continued to maintain that risks are 
acceptable. The commenters also contended that in addition to never 
adding these risks, the EPA has not provided a reasoned justification 
in the record for not doing so. The commenters added that the EPA 
recognized risks were unacceptable for a similar set of risks (e.g., 
lead smelting and ferroalloys) as those in the Petroleum Refinery RTR, 
and, thus, the risk for the Petroleum Refinery RTR should also be found 
unacceptable.
    Further, the commenters noted that the EPA's refined multipathway 
risk assessment for one refinery, for which the EPA indicates that the 
sum of the multipathway and inhalation risks for that facility is less 
than 100-in-1 million, conflicts with the fact that the inhalation risk 
alone is at least 100-in-1 million; it is unclear how combined risks 
would not exceed 100-in-1 million. Finally, the commenters stated that 
the EPA has not supported the conclusion based on data in the record 
that after performing a refined risk assessment on one refinery that 
cancer risk for all facilities can be discounted.
    Response C.2: As an initial matter, it is important to note that a 
risk level of 100-in-1 million is a presumptive limit of acceptability, 
not a threshold for acceptability or regulatory action. As stated in 
the Benzene NESHAP (54 FR 38044, 38061, September 14, 1989), in 
determining the need for residual risk standards, we strive to limit to 
no higher than approximately 100-in-1 million the estimated cancer risk 
that a person living near a plant would have if he or she were exposed 
to the maximum pollutant concentrations for 70 years and, in the ample 
margin of safety decision, to protect the greatest number of persons 
possible to an individual lifetime risk level of no higher than 
approximately 1-in-1 million. In determining whether risk is acceptable 
under CAA section 112(f), these levels are not rigid lines, and we 
weigh the cancer risk values with a series of other health measures and 
factors, including the specific uncertainties of the emissions, health 
effects, and risk information for the relevant source category, in both 
the decision regarding risk acceptability and in the ample margin of 
safety determination. The source category-specific decision of what 
constitutes an acceptable level of risk and whether it is necessary to 
promulgate more stringent standards to provide an ample margin of 
safety is a holistic one; that is, the EPA considers all potential 
health impacts--chronic and acute, cancer and noncancer, and 
multipathway--along with their uncertainties.
    With regard to the analysis performed for the refinery standards at 
issue here, the estimated risk of 100-in-1 million is based on a risk 
analysis using the MACT-allowable HAP emissions from a model plant, 
while the estimated risk based on actual HAP emissions from refineries 
is no greater than approximately 60-in-1 million and may be closer to 
40-in-1 million based on updated data received during the comment 
period. The model plant screening approach used to assess MACT-
allowable HAP emissions used several health protective assumptions 
including co-locating all sources at a refinery at a single location. 
The screening analysis used to estimate risk from non-routine PRD and 
flare emissions is also based on several health protective assumptions. 
Because of the conservative nature of these screening analyses, the EPA 
does not typically add their results (i.e., risk estimates from the 
model plant non-routine PRD and flare emissions to risk estimates from 
model plant allowable emissions). Further, we do not add the 
multipathway (non-inhalation) risks to inhalation risks because it is 
highly unlikely that the person exposed to the highest inhalation risk 
is the same person exposed to the highest refined multipathway 
(ingestion) risks. Overall risk results are presented to one 
significant digit, thus, even if we were to add the non-inhalation risk 
of 4-in-1 million to the 100-in-1 million risk from inhalation, we 
would still assess the total risk based on allowable emissions as 100-
in-1 million.
    Regarding the refined multipathway analysis performed on a single 
facility, as stated in the risk report, the EPA performed the refined 
analysis to gain a better understanding of the uncertainty associated 
with the multipathway Tier I and II screening analyses. The site, 
Marathon Ashland Petroleum facility (NEI6087) near Garyville in St. 
John the Baptist Parish, Louisiana, was among those that exceeded the 
Tier I screen for any HAP known to be persistent and bio-accumulative 
in the environment (PB-HAP), and it was among the refineries that had 
the greatest exceedance of a Tier II threshold for any PB-HAP. It also 
was selected based on the feasibility, with respect to the modeling 
framework, of obtaining model parameters for the region surrounding the 
refinery. The exposure estimates (and the risks calculated for those 
exposures) are anticipated to be among the highest that might be 
encountered for this source category because of the proximity of 
waterbodies

[[Page 6076]]

as well as agricultural lands. We note that many of the refineries did 
not exceed the Tier I screen, and for those that did, the levels of the 
exceedances were generally less than the level of exceedance exhibited 
by the facility selected for the refined assessment. Because the other 
facilities had a similar or lower exceedance of the screening level, 
the results of the refined assessment for this facility led us to 
conclude that if refined analyses were performed for other sites, the 
risk estimates would similarly be reduced from their Tier II estimates.
    Comment C.3: A commenter stated that the EPA acknowledged that 
people of color and those with low incomes are disproportionately 
exposed to risk from refinery emissions. The commenter asserted that 
the EPA has not provided a rational explanation why the unfair 
distribution of this risk does not lead to an unacceptable risk finding 
or at least require additional protections to assure an ample margin of 
safety to protect public health for all exposed persons.
    Response C.3: Following the analysis that CAA section 112(f)(2) 
requires, the EPA determined that the risk posed by emissions from the 
Petroleum Refinery source category were acceptable. After considering 
whether additional standards were required to provide an ample margin 
of safety to protect public health, including the health of people of 
color and those with low income, the EPA established additional control 
requirements for storage vessels. The December 2015 rule reduces risk 
for millions of people living near petroleum refineries and provides an 
ample margin of safety to protect public health. The NESHAP accordingly 
provides an ample margin of safety for all proximate populations, 
including people of color and those with low incomes.
    Comment C.4: A commenter stated that the EPA's risk assessment and 
determination are unlawful and are arbitrary and capricious because 
they are based on internally contradictory findings that, although 
acute risk is high (citing an HQ of 14 due to benzene from non-routine 
PRD and flare emissions), exposure to these non-routine emissions will 
rarely occur. The commenter asserted that the EPA's own record shows 
that non-routine emissions occur frequently: Every 4.4 to 6 years at 
all refineries, 16.7 percent probability of having an event in any 
given year, and that over a long period of time, such as 20 years, half 
of the best performers would have two events in a 3-year period. The 
commenter added that the December 2015 rule will allow these non-
routine emissions events to happen even more frequently. The commenter 
further asserted that the EPA's justification to discount this high 
acute risk was by stating that it could have used the acute exposure 
guideline level (AEGL) or ERPG level to develop a lower acute risk 
value than the value developed for the published risk assessment which 
was based on the REL. The commenter stated that the AEGL and ERPG level 
are designed to be used in a true emergency and not to set health 
protective standards that will generally apply at all times, adding 
that the AEGL, unlike the REL, does not incorporate consideration of 
vulnerability, such as for children, or community exposure over time. 
The commenter stated that the use of the AEGL and ERPG numbers would be 
expected to substantially underestimate risk and using them as 
justification to discount the high acute risk is arbitrary and 
capricious.
    Response C.4: As an initial matter, we disagree with the 
characterization that the work practice standards in the December 2015 
rule for flares and PRDs will allow non-routine events to occur more 
frequently than they do now. Prior to promulgation of the flare 
requirements and the PRD provisions, the MACT did not include any 
specific regulatory requirements that applied to these events. As noted 
in sections III.A and B above, the final work practice standards 
include requirements that are designed to reduce the number and 
magnitude of these types of releases. The commenters have not explained 
why the new requirements would increase the frequency and/or magnitude 
of these events.
    In May 2018, based on examination of California EPA's acute (1-
hour) REL for benzene, and considering aspects of the methodology used 
in the derivation of the value and how this assessment stands in 
comparison to the Agency for Toxic Substances and Disease Registry's 
toxicological assessment, EPA toxicologists decided it is not 
appropriate to use the benzene REL value to support the EPA's RTR 
rules. In lieu of using the REL in RTR risk assessments, the EPA is now 
evaluating acute benzene risks by comparing potential exposure levels 
to the ERPG-1 values. In this case, the acute HQ value from non-routine 
PRD and flare emissions is 0.07 when comparing ambient levels to the 
ERPG-1. To better characterize the potential health risks associated 
with estimated worst-case acute exposures to HAP, and in response to a 
key recommendation from the Science Advisory Board's peer review of the 
EPA's RTR risk assessment methodologies, we now examine a wider range 
of available acute health metrics than we do for our chronic risk 
assessments. This is in acknowledgement that there are generally more 
data gaps and uncertainties in acute reference values than there are in 
chronic reference values. The acute REL represents a health-protective 
level of exposure, with effects not anticipated below those levels, 
even for repeated exposures. Although the potential for effects 
increases as exposure concentration increases above the acute REL, the 
level of exposure greater than the REL that would cause health effects 
is not specifically known. Therefore, when an REL is exceeded and an 
AEGL-1 or ERPG-1 level is available (i.e., levels at which mild, 
reversible effects are anticipated in the general public for a single 
exposure), we typically use them as an additional comparative measure, 
as they provide an upper bound for exposure levels above which exposed 
individuals could experience effects. The worst-case maximum estimated 
1-hour exposure to benzene outside the facility fence line is less than 
the AEGL-1 or ERPG-1 levels.
3. What is the EPA's final decision on the risk assessment?
    As supported by the screening analysis published with the December 
2015 rule, the additional risk from the PRD and emergency flaring work 
practice standards did not significantly alter the risk estimates in 
the EPA's 2014 analysis. In response to the current proposal, we did 
not receive any new information or other basis that would support a 
change to the risk analysis and the determination that the risk from 
the source category is acceptable and that, as modified by the December 
2015 rule, the MACT standards provide an ample margin of safety to 
protect public health.

D. Issue 4: Alternative Work Practice Standards for DCUs Employing the 
Water Overflow Design

1. What is the history of the alternative work practice standards for 
DCUs employing the water overflow design?
    In the December 2015 rule, we finalized MACT standards for DCU 
decoking operations. The rule provided that existing DCU-affected 
sources must comply with a 2 psig or 220 degrees Fahrenheit ([deg]F) 
limit in the drum overhead line determined on a rolling 60-event basis 
prior to venting to the atmosphere, draining, or deheading the coke 
drum. New DCU-affected sources must comply with a 2.0 psig or 218 
[deg]F limit in the drum overhead line on a per-event, not-to-exceed 
basis. In the

[[Page 6077]]

December 2015 rule, we also finalized an alternative requirement that 
we did not propose to address DCU with water overflow design, where 
pressure monitoring would not be appropriate. As part of these 
provisions, we included a new requirement in the December 2015 rule for 
DCU with water overflow design to hard-pipe the overflow drain water to 
the receiving tank via a submerged fill pipe (pipe below the existing 
liquid level) whenever the overflow water exceeds 220 [deg]F.
    We requested public comment on the alternative work practice 
standard for delayed coking units employing a water overflow design 
provided in 40 CFR 63.657(e).
    In response to the comments received on the October 2016 proposed 
notice of reconsideration regarding the alternative work practice 
standards for DCU employing the water overflow design, we proposed 
amendments on April 10, 2018 (April 2018 proposal) (see 83 FR 15458), 
to the water overflow requirements in 40 CFR 63.657(e). The EPA has 
issued a final rule which was promulgated on November 26, 2018 
(November 2018 rule) fully addressing this issue and responding to all 
of the comments on the proposal for this rule as well as the April 2018 
proposal.

E. Issue 5: Alternative Sampling Frequency for Burden Reduction for 
Fenceline Monitoring

1. What is the history of the alternative sampling frequency for burden 
reduction for fenceline monitoring?
    In the December 2015 rule, we revised Refinery MACT 1 to establish 
a work practice standard requiring refinery owners to monitor benzene 
concentrations around the fenceline or perimeter of the refinery. We 
promulgated new EPA Methods 325A and B which specify monitor siting and 
quantitative sample analysis procedures. The work practice is designed 
to improve the management of fugitive emissions at petroleum refineries 
through the use of passive monitors by requiring sources to implement 
corrective measures if the benzene concentration in air attributable to 
emissions from the refinery exceeds a fenceline benzene concentration 
action level. The work practice requires refinery owners to maintain 
fenceline benzene concentrations at or below the concentration action 
level of 9 [mu]g/m\3\. In the December 2015 rule, we included 
provisions that were not proposed that would allow for reduced 
monitoring frequency (after 2 years of continual monitoring) at 
monitoring locations that record concentrations below 0.9 [mu]g/m\3\ 
[see 40 CFR 63.658(e)(3)].
    We requested public comment on the provision allowing refineries to 
reduce the frequency of fenceline monitoring at monitoring locations 
that consistently record benzene concentrations below 0.9 [mu]g/m\3\.
2. What comments were received on the alternative sampling frequency 
for fenceline monitoring?
    Comment E.1: Commenters asserted that setting the threshold for 
reducing the frequency of fenceline monitoring at 0.9 [mu]g/m\3\ is 
arbitrary and capricious. The commenters stated that the EPA's modeling 
predicted that more than half (81 of 142) of the refineries modeled 
would have fenceline concentrations equal to or less than 0.4 [mu]g/
m\3\, and, thus, it is unlikely these facilities will have any monitors 
register concentrations in excess of the threshold. Therefore, these 
refineries will likely qualify for reduced monitoring, although they 
could have malfunctioning equipment causing benzene levels to be double 
the EPA's modeled amount.
    The commenter added that while the fenceline concentrations modeled 
by the EPA do not include background ambient concentrations of benzene 
which will contribute to the benzene concentration measured at each 
monitor, it is still likely that the eligibility threshold for reduced 
frequency monitoring is too high and will allow operators to reduce the 
monitoring frequency at downwind monitors. The commenter supported this 
statement by referencing the API Corrected Fenceline Monitoring 
Results, Docket ID Item No. EPA-HQ-OAR-2010-0682-0752, which showed 
that at least 25 percent of facilities would be eligible for reduced 
monitoring at more than half of the monitoring sites based on the 0.9 
[mu]g/m\3\ threshold.
    Response E.1: We disagree that entire refineries will be able to 
qualify for reduced monitoring frequency. As the commenters themselves 
noted, the Agency's modeled concentrations provide only the impact of 
refinery emissions on the ambient air concentration (the [Delta]C) and 
do not include background concentrations. The modeling does not allow 
us to evaluate the total (refinery plus background) concentration level 
at any one location. Second, we note that the API study was a 3-month 
study that occurred primarily in the winter months when fugitive 
emissions are expected to be at their lowest. We also considered the 
Corpus Christi year-long study and a comparison of the concentrations 
observed throughout the year. That study showed that benzene 
concentrations at the fenceline are higher during warmer weather 
because most fugitive emission sources, such as storage tanks and 
wastewater, have a significant temperature dependency. The reduced 
monitoring provisions require 2 full years (52 consecutive 2-week 
samples) where the highest single value, not the average concentration 
at that location, is less than 0.9 [mu]g/m\3\. Based on the data we 
have available, we consider that only a few monitoring locations will 
qualify for reduced frequency monitoring based on this 2-year 
requirement that all sample concentrations at the location are less 
than 0.9 [mu]g/m\3\.
    In addition, we selected this value to be consistent with the 
minimum detection limit we required for an alternative monitoring 
method. It seemed incongruous to allow an alternative monitoring method 
with a detection limit of 0.9 [mu]g/m\3\ to be used to comply with the 
rule but then establish a burden reduction alternative that used a 
lower concentration level. Ultimately, we are confident that only a 
limited number of sampling locations at any petroleum refinery will 
meet the burden reduction criteria. We considered it reasonable to 
provide incentives for refinery owners or operators to achieve even 
greater reductions than are required by the 9 [mu]g/m\3\ [Delta]C 
action level, and the final burden reduction provisions provide such an 
incentive without compromising the overall objectives of the program.
    Comment E.2: One commenter stated that the provisions allowing 
refineries to reduce the frequency of fenceline monitoring are unlawful 
and are arbitrary and capricious. To support this statement, the 
commenter stated that a reduction in burden to the fenceline monitoring 
program will not allow the program to serve its intended purpose: To 
enable operators to identify leaks or operating problems at equipment 
that cannot practically be monitored, tested, or evaluated for 
compliance on a frequent basis. In further support of their argument, 
the commenters explained that the risk findings for the December 2015 
rule hinge on the frequency of the fenceline monitoring cycle. The 
commenter stated that the EPA is on record stating that if the emission 
inventories or risk assessment do understate actual emissions, as some 
commenters have alleged, the fenceline monitoring and corrective action 
requirements will ensure refineries reduce their actual emissions to 
levels comparable to their emissions inventories, and that in doing so, 
will

[[Page 6078]]

ensure communities surrounding petroleum refineries would be protected 
to acceptable risk levels. Therefore, the commenter asserted that it is 
imperative for the EPA to maintain the 2-week monitoring cycle to 
ensure operators are quickly identifying malfunctioning equipment and 
to close the gap between actual and reported emissions.
    On the other hand, some commenters stated that the alternative 
monitoring provisions did not go far enough at reducing burden. Some 
commenters suggested that after 2 years of demonstrating a background-
corrected maximum fenceline annual average concentration ([Delta]C) 
below the action level, monitoring frequency be reduced to a 2-week 
period every quarter for all monitoring locations. If the background-
corrected annual average benzene concentration based on the quarterly 
monitoring exceeds the action level, a return to more frequent 
monitoring could be required RCA/CAA requirement. The reduced 
monitoring frequency could be available again after 1 year of meeting 
the action level. Another commenter recommended that the reduced 
monitoring provision be removed in favor of a one-time demonstration 
that the annual fenceline benzene [Delta]C concentration is less than 
50 percent of the action level during normal operations.
    Response E.2: With respect to the commenter's opposition to the 
alternative sampling frequency, it is important to understand that the 
alternative sampling frequency provision in the December 2015 rule does 
not reduce the frequency by which the [Delta]C values must be 
determined. This is because the reduced sampling frequency provision 
will impact only selected locations that have monitored benzene 
concentrations below 0.9 [mu]g/m\3\ based on 2 full years of data. 
Refineries will still collect samples at all other locations during 
each 2-week period and will still determine the [Delta]C value for each 
sampling interval and include the [Delta]C for the sampling interval in 
the annual average [Delta]C value calculation. Therefore, we still 
expect the fenceline monitoring program as included in the December 
2015 rule to achieve its purpose of more timely detection and 
correction of issues that can lead to high fugitive emissions.
    The burden reduction alternatives suggested by some commenters 
would significantly limit the effectiveness of the fenceline monitoring 
program to identify issues early. A one-time determination completely 
defeats this purpose and could not possibly be done in a manner 
representative of the variety of circumstances that can occur 
throughout the year or the lifetime of a facility. The purpose of the 
fenceline monitoring program is to allow for detection and correction 
of issues that may cause abnormally high emissions, such as large leaks 
in valves, tears in rim seals of floating roof storage vessels, and 
other unexpected, difficult to predict events. A one-time determination 
does not allow the fenceline monitoring program to timely and 
effectively identify these issues on an on-going basis.
    While quarterly determinations would be more effective than a one-
time determination for on-going fugitive management, quarterly 
determinations are less effective in improving fugitive emissions 
management than continual 2-week sampling. First, for large leak 
events, the emissions may continue for months prior to being detected 
under quarterly monitoring versus being detected in a week or two under 
continual 2-week sampling. Thus, the emission reduction achieved by the 
quarterly monitoring would not be as great as by continual 2-week 
monitoring. Second, under the quarterly monitoring option, there would 
be large periods of time when no monitoring will be performed. The 
passive diffusive tubes cannot be deployed over such a long time 
period. Thus, we assume that quarterly monitoring would consist of a 2-
week sampling period once every quarter. As such, for more than 80 
percent of the time, no monitoring would be conducted at the fenceline. 
Consequently, quarterly monitoring would often miss periodic emission 
events, such as tank cleaning and/or filling, which can lead to high 
short-term emissions. These short-term events can contribute 
significantly to a facility's emissions and their contribution would be 
captured via the continual 2-week sampling, but likely missed under a 
quarterly monitoring approach. In order to effectively manage all 
fugitive emission sources, including periodic releases, we determined 
that the continual 2-week sampling period should be maintained for the 
overall program. By providing a monitoring skip period only to 
locations that do not exceed 0.9 [mu]g/m\3\ for any sampling interval 
for 2 full years (52 consecutive 2-week sampling periods), we maintain 
continual 2-week sampling at all locations that may contribute to an 
exceedance of the action level and ensure on-going enhanced management 
of fugitive emissions.
    Comment E.3: Commenters stated that the rule does not include 
provisions for re-instating the monitoring frequency for those monitors 
which may at one time qualify for reduced monitoring.
    Response E.3: We disagree. Section 63.658(e)(v) of the final rule 
provides that any location with a value above 0.9 [mu]g/m\3\ while 
reduced monitoring is being implemented will subject the owner or 
operator to a 3-month ``probationary period'' where samples must be 
collected every 2 weeks at that location. If the concentrations during 
the probationary period are all at or below 0.9 [mu]g/m\3\, the owner 
or operator may continue with the monitoring frequency prior to the 
excursion. If any other sample during the probationary period exceeds 
0.9 [mu]g/m\3\, then the owner or operator must comply with the more 
stringent monitoring requirements and would not be eligible for reduced 
monitoring frequency until completion of a new 2-year period at that 
more stringent monitoring frequency.
    Comment E.4: A commenter stated that despite the EPA's claims that 
it is allowing less frequent monitoring to reduce burden, there is no 
quantified or otherwise evaluated data available in the record related 
to the actual burden reduction.
    Response E.4: We did not specifically develop burden reduction 
estimates associated with this provision for several reasons. First, 
fenceline monitoring must be performed for a full 2 years prior to the 
burden reduction provisions applying to any monitoring location, so 
estimating the burden of the fenceline monitoring provisions without 
consideration of the burden reduction provisions provides an accurate 
estimate of the annual burden for the first 2 years. Second, we were 
uncertain how many monitoring locations would qualify for the burden 
reduction provision. Third, with respect to the burden estimate for the 
December 2015 rule as provided in the Supporting Statement for the 
Office of Management and Budget's (OMB's) ICR, we estimated the costs 
of the on-going fenceline monitoring program assuming all samples would 
continue to be collected during the 3-year period covered by the ICR.
    Based on the burden estimate detail provided in the attachments to 
the memorandum, ``Fenceline Monitoring Impact Estimates for Final 
Rule'' (see Docket ID Item No. EPA-HQ-OAR-2010-0682-0749), we estimate 
that each time a sample does not need to be collected at a specific 
location there will be a burden reduction of 0.3 technical hours (0.25 
hours reduced during sample collection and 0.05 hours reduced during 
sample analyses). Considering management and clerical hours, the total 
burden reduction per sample skipped would be 0.35 hours and 
approximately $29. As an example

[[Page 6079]]

of potential burden reduction, if a facility could use the monthly 
reduced monitoring provisions for two locations in a given year (26 
skipped samples, 13 at each site), the burden reduction for that 
facility would be 9 hours and $745 each year.
    Comment E.5: One commenter recommended that the EPA reduce burden 
by providing a mechanism to use existing HAP ambient monitoring 
programs as an acceptable alternative to the EPA fenceline monitoring 
program.
    Response E.5: We provided a mechanism and criteria by which a 
refinery owner or operator may submit a request for an alternative test 
method to the passive diffusive tube fenceline monitoring methods (EPA 
Methods 325A and 325B). These provisions are included at 40 CFR 
63.658(k) of the final rule.
3. What is EPA's final decision on the alternative sampling frequency 
for fenceline monitoring?
    For fenceline monitoring requirements, the alternative sampling 
frequency requirements will not alter the effectiveness of the program 
as the requirements do not change the facility-level procedures and 
frequency for calculating and reporting [Delta]C (see Response E.1). 
Furthermore, the 0.9 [mu]g/m\3\ threshold for reducing the frequency of 
fenceline monitoring is appropriate based on the available data and it 
is consistent with the minimum detection limit required for alternative 
monitoring methods. We have not been presented with any comments and/or 
information in response to the October 2016 proposed notice of 
reconsideration relative to the alternative sampling frequency for 
fenceline monitoring which will result in any changes to the December 
2015 rule.

F. Additional Proposed Clarifying Amendments

1. What is the history of the proposed clarifying amendments?
    The EPA proposed to amend provisions related to the overlap 
requirements for equipment leaks that are contained in Refinery MACT 1 
and in the Refinery Equipment Leak NSPS (40 CFR part 60, subpart GGGa). 
The Refinery MACT 1 provision at 40 CFR 63.640(p)(2) states that 
equipment leaks that are subject to the provisions in the Refinery 
Equipment Leak NSPS (40 CFR part 60, subpart GGGa) are only required to 
comply with the provisions in the Refinery Equipment Leak NSPS. 
However, the Refinery Equipment Leak NSPS does not include the new work 
practice standards finalized in the final Refinery MACT 1 at 40 CFR 
63.648(j) which apply to releases from PRDs. We intended that these new 
work practice standards would be applicable to all PRDs at refineries, 
including those PRDs subject to the requirements in the Refinery 
Equipment Leaks NSPS. In order to provide clarity and assure that 
refiners subject to these provisions fully understand their compliance 
obligations, we proposed to modify the equipment leak requirement to 
provide that PRDs in organic HAP service must comply with the 
requirements in Refinery MACT 1 at 40 CFR 63.648(j) for PRDs. We also 
proposed to amend the introductory text in 40 CFR 63.648(j) to 
reference the Refinery Equipment Leaks NSPS at 40 CFR 60.482-4a and 
amend paragraphs (j)(2)(i) through (iii) of Refinery MACT 1 to correct 
the existing reference to 40 CFR 60.485(b), to instead refer to 40 CFR 
60.485(c) and 40 CFR 60.485a(c). As noted in section III.B.1 of this 
preamble, we also proposed to revise the incorrect cross-reference to 
PRD prevention measures at 40 CFR 63.670(o)(1)(ii)(B) from 40 CFR 
63.648(j)(5) to 63.648(j)(3)(ii). However, we concluded it would be 
more accurate to cross-reference 40 CFR 63.648(j)(3)(ii)(A) through (E) 
rather than the entirety of 40 CFR 63.648(j)(3)(ii). Therefore, in the 
April 2018 proposal, we proposed this clarified revision and finalized 
this revision as proposed in the November 2018 rule.
2. What comments were received on the proposed clarifying amendments?
    Comment F.1: Commenters asserted that the EPA's proposal to modify 
the provisions in 40 CFR 63.640(p)(2) by providing that PRDs in organic 
HAP service must comply with the requirements in 40 CFR 63.648(j) is 
arbitrary and capricious. Commenters opposed the proposed revisions 
claiming they would enshrine exemptions from NSPS equipment leak 
standards for new and modified PRD or allow for substitution of NSPS 
requirements for the work practice standards in 40 CFR 63.648(j), which 
they believe are exemptions from malfunction requirements. They added 
that these provisions amend the NSPS for Petroleum Refineries without 
satisfying the appropriate procedural and substantive legal tests 
required to do so.
    Response F.1: It appears that the commenter misunderstands the 
proposed amendment. When we revised Refinery MACT 1 at 40 CFR 63.648(j) 
to add PRD requirements, we failed to recognize that the NSPS overlap 
provisions in 40 CFR 63.640(p)(2) could be used as a ``loophole'' by 
refinery owners and operators to not implement three prevention 
measures and to not perform the root cause analysis or implement 
corrective actions. This is because the NSPS subpart GGGa does not have 
any pressure release management requirements. In the absence of the 
proposed amendment, the existing overlap provision states that 
``Equipment leaks that are also subject to the provisions of 40 CFR 
part 60, subpart GGGa, are required to comply only with the provisions 
specified in 40 CFR part 60, subpart GGGa.'' Thus, PRDs subject to 40 
CFR part 60, subpart GGGa, were inadvertently exempted from the new PRD 
pressure release management requirements. We understand that the 
commenter does not support some of the provisions in the pressure 
release management requirements in the final Refinery MACT 1 rule, but 
these requirements are clearly more stringent than the NSPS subpart 
GGGa provisions for PRDs which only require monitoring of the PRD after 
a release, and do not have any restrictions or requirements to limit 
PRD releases. We note that in addition to the new PRD requirements 
established in the December 2015 rule, the Refinery MACT 1 PRD 
requirements at 40 CFR 63.648(j)(1) and (2) fully include those 
requirements that would apply under 40 CFR part 60, subpart GGGa. In 
reviewing standards covering the same pieces of equipment, we look to 
identify the overlapping standards and require the owner or operator to 
comply only with the most stringent standard. After the revisions to 
the PRD requirements in Refinery MACT 1, we determined that the 
equipment leak provisions for PRDs in Refinery MACT 1 are more 
stringent than those in 40 CFR part 60, subpart GGGa. By revising this 
overlap provision, we are requiring equipment leak sources that are 
subject to both rules to comply with the 40 CFR part 60, subpart GGGa 
for most equipment leak sources but PRDs must comply with the PRD 
requirements in Refinery MACT 1. This revision will require PRDs that 
are also subject to 40 CFR part 60, subpart GGGa, to implement 
prevention measures for PRDs, conduct root cause analyses, and 
implement corrective actions to prevent a similar release from 
occurring. Because compliance with 40 CFR part 60, subpart GGGa is not 
sufficient to demonstrate compliance with Refinery MACT 1 PRD 
provisions, revision of the existing overlap provisions was deemed 
critical to ensure all Refinery MACT 1 PRDs comply with the new 
pressure release management requirements.

[[Page 6080]]

    The commenter is also mistaken that this provision amends the NSPS. 
Rather, it defines what sources subject to Refinery MACT 1 must do to 
comply with Refinery MACT 1. Specifically, for equipment leaks at 
facilities subject to both Refinery MACT 1 and 40 CFR part 60, subpart 
GGGa, owners and operators must comply with the requirements in 
Refinery MACT 1 (40 CFR part 63, subpart CC) for PRDs associated with 
the leaking equipment because the requirements in Refinery MACT 1 for 
PRDs are more stringent than those in 40 CFR part 60, subpart GGGa. The 
NSPS requirements are not modified by this change to 40 CFR part 63, 
subpart CC and remain in effect for PRDs associated with equipment 
leaks that are not subject to Refinery MACT 1.
    Comment F.2: Commenters supported the clarification to the overlap 
provisions for equipment leaks in 40 CFR 63.640(p)(2), but also request 
that a delay of repair provision be included in 40 CFR 63.648 because 
other equipment leak rules (such as 40 CFR part 60, subparts GGG and 
GGGa) potentially applicable to refinery PRDs include such delay of 
repair provisions. The commenters noted that PRDs subject to 40 CFR 
part 60, subpart GGG, are made subject to 40 CFR 63.648(j) by 40 CFR 
63.640(p)(1).
    Response F.2: By proposing a technical correction to 40 CFR 
63.640(p)(2), the EPA was not proposing to re-open the substantive 
requirements of 40 CFR 63.640 nor of other provisions, such as 40 CFR 
63.648 that may be referenced in 40 CFR 63.640. We also disagree that 
PRDs are allowed to comply with delay of repair provisions in the NSPS 
(subparts GGG/GGGa or VV/Vva) beyond taking the equipment out of VOC 
service. In any case, we determined that it was contrary to safety and 
good air pollution control practices to continue to operate a process 
unit without a properly functioning PRD as PRDs are, primarily, safety 
devices.
3. What is the EPA's final decision on the proposed clarifying 
amendments?
    We are finalizing the amendment that equipment leaks that are 
subject to the provisions of the Refinery Equipment Leak NSPS pursuant 
to 40 CFR 63.640(p)(2) must comply with the requirements in Refinery 
MACT 1 at 40 CFR 63.648(j) for PRDs, as proposed. We are also 
finalizing the amendment to the introductory text in 40 CFR 63.648(j) 
to reference Refinery Equipment Leaks NSPS at 40 CFR 60.482-4a and the 
amendment to paragraphs (j)(2)(i) through (iii) of Refinery MACT 1 to 
correct the existing reference to 40 CFR 60.485(b), which should refer 
to 40 CFR 60.485(c) and 40 CFR 60.485a(c), as proposed. Finally, as 
noted in the history of these clarifying amendments, we addressed the 
proposed amendments at 40 CFR 63.670(o)(1)(ii)(B) in a final rule 
issued in November 2018 to more accurately cross-reference 40 CFR 
63.648(j)(3)(ii)(A) through (E) rather than the entirety of 40 CFR 
63.648(j)(3)(ii).

G. Corrections to November 2018 Final Rule

    There were a number of publication errors associated with the 
November 2018 rule. Several of these errors were associated with 
inaccurate amendatory instructions or editorial errors in the final 
amendment package. We are correcting these errors to finalize the 
amendments consistent with the intent of the preamble to the November 
2018 final rule (83 FR 60696). Table 2 of this preamble provides a 
summary of the publication and editorial errors in the November 2018 
rule that we are correcting in this final action.

          Table 2--Summary of Corrections to November 2018 Rule
------------------------------------------------------------------------
           Provision                  Issue            Final revision
------------------------------------------------------------------------
                             Refinery MACT 1
------------------------------------------------------------------------
40 CFR 63.641, definition of    Incorrect          Revise instructions
 ``Reference control             amendatory         and reprint the
 technology for storage          instructions;      entire definition to
 vessels''.                      the Code of        more easily
                                 Federal            implement revisions
                                 Regulations        to the definition of
                                 could not          ``Reference control
                                 implement          technology for
                                 revisions as       storage vessels''
                                 instructed.        consistent with the
                                                    intent of the
                                                    preamble to the
                                                    November 2018 final
                                                    rule.
40 CFR 63.643(c)(1)(v)........  There is a comma   Amend 40 CFR
                                 after the word     63.643(c)(1)(v) to
                                 ``less.'' It       replace the comma
                                 should be a        after the word
                                 period.            ``less'' with a
                                                    period.
40 CFR 63.655(f)(1)(iii)......  Subordinate        Amend 40 CFR
                                 paragraphs (A)     63.655(f)(1)(iii) to
                                 and (B) were       include subordinate
                                 inadvertently      paragraphs (A) and
                                 removed due to     (B) consistent with
                                 incorrect          the intent of the
                                 amendatory         preamble to the
                                 instructions.      November 2018 final
                                                    rule.
40 CFR 63.655(f)(2)...........  Subordinate        Amend 40 CFR
                                 paragraphs (i)     63.655(f)(2) to
                                 through (iii)      include subordinate
                                 were               paragraphs (i)
                                 inadvertently      through (iii)
                                 removed due to     consistent with the
                                 incorrect          intent of the
                                 amendatory         preamble to the
                                 instructions.      November 2018 final
                                                    rule.
40 CFR 63.655(h)(10)..........  The introductory   Amend 40 CFR
                                 text associated    63.655(h)(10)
                                 with this          introductory text to
                                 paragraph was      read as ``Extensions
                                 missing from the   to electronic
                                 regulatory text    reporting
                                 included in the    deadlines.''
                                 rule as
                                 published in the
                                 Federal Register.
40 CFR 63.655(i)(11) ``. . .    Pilot-operated     Amend 40 CFR
 For each pilot-operated         PRDs are not       63.655(i)(11)
 pressure relief device          subject to         introductory text to
 subject to the requirements     requirements at    remove ``or (iii).''
 at 40 CFR 63.648(j)(4)(ii) or   40 CFR
 (iii), . . .''.                 63.648(j)(4)(iii
                                 ) so the
                                 inclusion of
                                 ``or (iii)'' was
                                 incorrect.
40 CFR 63.660(i)(2)(iii).       Use of the plural  Amend 40 CFR
 ``Use a cap, blind flange,      in referencing     63.660(i)(2)(iii) to
 plug, or a second valve for     ``. . . an open-   read ``Use a cap,
 an open-ended valves or line    ended valves . .   blind flange, plug,
 . . .''.                        .'' is incorrect   or a second valve
                                 grammar.           for an open-ended
                                                    valve or line . .
                                                    .''
40 CFR 63.670(d)(2)...........  Equation term      Amend the reference
                                 NHVvg              in the equation term
                                 incorrectly        NHVvg in 40 CFR
                                 references         63.670(d)(2) from
                                 paragraph (l)(4)   (l)(4) to (k)(4).
                                 and should
                                 instead
                                 reference (k)(4).
------------------------------------------------------------------------

[[Page 6081]]

 
                             Refinery MACT 2
------------------------------------------------------------------------
Table 4 to Subpart UUU, Item    The ``1'' should   Amend Item 9.c. of
 9.c. ``XRF procedure in         be superscripted   Table 4 to Subpart
 appendix A to this subpart 1;   as it is           UUU to read. ``XRF
 . . .''.                        intended to        procedure in
                                 identify           appendix A to this
                                 footnote 1.        subpart; \1\ . . .''
------------------------------------------------------------------------

IV. Summary of Cost, Environmental, and Economic Impacts

    As described in section III of this preamble, the EPA is not 
revising the 2015 Rule requirements for: (1) The work practice 
standards for PRDs; (2) the work practice standards for emergency 
flaring events; (3) the assessment of risk as modified based on 
implementation of these PRD and emergency flaring work practice 
standards; or (4) the provision allowing refineries to reduce the 
frequency of fenceline monitoring at sampling locations that 
consistently record benzene concentrations below 0.9 [micro]g/m\3\. In 
this action, the EPA is finalizing two clarifying amendments which were 
included in the proposed notice of reconsideration. These amendments 
are not expected to have any cost, environmental, or economic impacts. 
Therefore, the burden estimates and economic impact analysis associated 
with the December 2015 rule (available in Docket ID No. EPA-HQ-OAR-
2010-0682) have not been altered as a result of this action. We note 
that in the November 2018 rule, the EPA revised the requirements for 
the alternative water overflow provisions for DCUs. A discussion of the 
cost, environmental, and economic impacts of the amendments for the 
water overflow provisions for DCUs were included in the April 2018 
proposal and the November 2018 rule.

V. Statutory and Executive Order Reviews

    Additional information about these statutes and Executive Orders 
can be found at https://www.epa.gov/laws-regulations/laws-and-executive-orders.

A. Executive Order 12866: Regulatory Planning and Review and Executive 
Order 13563: Improving Regulation and Regulatory Review

    This action is not a significant regulatory action and was, 
therefore, not submitted to OMB for review.

B. Executive Order 13771: Reducing Regulation and Controlling 
Regulatory Costs

    This action is not an Executive Order 13771 regulatory action 
because this action is not significant under Executive Order 12866.

C. Paperwork Reduction Act (PRA)

    This action does not impose any new information collection burden 
under the PRA. OMB has previously approved the information collection 
activities contained in the existing regulations at 40 CFR part 63, 
subparts CC and UUU, and has assigned OMB control numbers 2060-0340 and 
2060-0554. The revisions adopted in this action are clarifications and 
technical corrections that do not affect the estimated burden of the 
existing rule. Therefore, we have not revised the information 
collection request for the existing rule.

D. Regulatory Flexibility Act (RFA)

    I certify that this action will not have a significant economic 
impact on a substantial number of small entities under the RFA. In 
making this determination, the impact of concern is any significant 
adverse economic impact on small entities. An agency may certify that a 
rule will not have a significant economic impact on a substantial 
number of small entities if the rule relieves regulatory burden, has no 
net burden, or otherwise has a positive economic effect on the small 
entities subject to the rule. The rule revisions being made through 
this action consist of clarifications and technical corrections which 
do not change the expected economic impact analysis performed for the 
December 2015 rule. We have, therefore, concluded that this action will 
have no net regulatory burden for all directly regulated small 
entities.

E. Unfunded Mandates Reform Act (UMRA)

    This action does not contain any unfunded mandate as described in 
UMRA, 2 U.S.C. 1531-1538, and does not significantly or uniquely affect 
small governments. The action imposes no enforceable duty on any state, 
local, or tribal governments or the private sector.

F. Executive Order 13132: Federalism

    This action does not have federalism implications. It will not have 
substantial direct effects on the states, on the relationship between 
the national government and the states, or on the distribution of power 
and responsibilities among the various levels of government.

G. Executive Order 13175: Consultation and Coordination With Indian 
Tribal Governments

    This action does not have tribal implications as specified in 
Executive Order 13175. It will not have substantial direct effect on 
tribal governments, on the relationship between the federal government 
and Indian tribes, or on the distribution of power and responsibilities 
between the federal government and Indian tribes, as specified in 
Executive Order 13175. Thus, Executive Order 13175 does not apply to 
this action.

H. Executive Order 13045: Protection of Children From Environmental 
Health Risks and Safety Risks

    This action is not subject to Executive Order 13045 because it is 
not economically significant as defined in Executive Order 12866, and 
because the environmental health or safety risks addressed by this 
action do not present a disproportionate risk to children. The actions 
taken in this rulemaking are technical clarifications and corrections 
and they do not affect risk for any populations.

I. Executive Order 13211: Actions Concerning Regulations That 
Significantly Affect Energy Supply, Distribution, or Use

    This action is not subject to Executive Order 13211 because it is 
not a significant regulatory action under Executive Order 12866.

J. National Technology Transfer and Advancement Act (NTTAA)

    This rulemaking does not involve technical standards.

[[Page 6082]]

K. Executive Order 12898: Federal Actions To Address Environmental 
Justice in Minority Populations and Low-Income Populations

    The EPA believes that this action does not have disproportionately 
high and adverse human health or environmental effects on minority 
populations, low-income populations, and/or indigenous peoples, as 
specified in Executive Order 12898 (59 FR 7629, February 16, 1994). The 
actions taken in this rulemaking are technical clarifications and 
corrections and they do not affect the risk for any populations.

L. Congressional Review Act (CRA)

    This action is subject to the CRA, and the EPA will submit a rule 
report to each House of the Congress and to the Comptroller General of 
the United States. This action is not a ``major rule'' as defined by 5 
U.S.C. 804(2).

List of Subjects in 40 CFR Part 63

    Environmental protection, Administrative practice and procedures, 
Air pollution control, Hazardous substances, Intergovernmental 
relations, Reporting and recordkeeping requirements.

    Dated: January 14, 2020.
Andrew R. Wheeler,
Administrator.

    For the reasons set forth in the preamble, the Environmental 
Protection Agency is amending 40 CFR part 63 as follows:

PART 63--NATIONAL EMISSION STANDARDS FOR HAZARDOUS AIR POLLUTANTS 
FOR SOURCE CATEGORIES

0
1. The authority citation for part 63 continues to read as follows:

    Authority: 42 U.S.C. 7401 et seq.

Subpart CC--National Emission Standards for Hazardous Air 
Pollutants from Petroleum Refineries

0
2. Section 63.640 is amended by revising paragraph (p)(2) to read as 
follows:

Sec.  63.640  Applicability and designation of affected source.

* * * * *
    (p) * * *
    (2) Equipment leaks that are also subject to the provisions of 40 
CFR part 60, subpart GGGa, are required to comply only with the 
provisions specified in 40 CFR part 60, subpart GGGa, except that 
pressure relief devices in organic HAP service must only comply with 
the requirements in Sec.  63.648(j).
* * * * *

0
3. Section 63.641 is amended by revising the definition of ``Reference 
control technology for storage vessels'' to read as follows:

Sec.  63.641  Definitions.

* * * * *
    Reference control technology for storage vessels means either:
    (1) For Group 1 storage vessels complying with Sec.  63.660:
    (i) An internal floating roof, including an external floating roof 
converted to an internal floating roof, meeting the specifications of 
Sec. Sec.  63.1063(a)(1)(i), (a)(2), and (b) and 63.660(b)(2);
    (ii) An external floating roof meeting the specifications of 
Sec. Sec.  63.1063(a)(1)(ii), (a)(2), and (b) and 63.660(b)(2); or
    (iii) [Reserved]
    (iv) A closed-vent system to a control device that reduces organic 
HAP emissions by 95 percent, or to an outlet concentration of 20 parts 
per million by volume (ppmv).
    (v) For purposes of emissions averaging, these four technologies 
are considered equivalent.
    (2) For all other storage vessels:
    (i) An internal floating roof meeting the specifications of Sec.  
63.119(b) of subpart G except for Sec.  63.119(b)(5) and (6);
    (ii) An external floating roof meeting the specifications of Sec.  
63.119(c) of subpart G except for Sec.  63.119(c)(2);
    (iii) An external floating roof converted to an internal floating 
roof meeting the specifications of Sec.  63.119(d) of subpart G except 
for Sec.  63.119(d)(2); or
    (iv) A closed-vent system to a control device that reduces organic 
HAP emissions by 95 percent, or to an outlet concentration of 20 parts 
per million by volume.
    (v) For purposes of emissions averaging, these four technologies 
are considered equivalent.
* * * * *

0
4. Section 63.643 is amended by revising paragraph (c)(1)(v) to read as 
follows:

Sec.  63.643  Miscellaneous process vent provisions.

* * * * *
    (c) * * *
    (1) * * *
    (v) If, after applying best practices to isolate and purge 
equipment served by a maintenance vent, none of the applicable 
criterion in paragraphs (c)(1)(i) through (iv) of this section can be 
met prior to installing or removing a blind flange or similar equipment 
blind, the pressure in the equipment served by the maintenance vent is 
reduced to 2 psig or less. Active purging of the equipment may be used 
provided the equipment pressure at the location where purge gas is 
introduced remains at 2 psig or less.
* * * * *

0
5. Section 63.648 is amended by revising paragraphs (j) introductory 
text and (j)(2)(i) through (iii) to read as follows:

Sec.  63.648  Equipment leak standards.

* * * * *
    (j) Except as specified in paragraph (j)(4) of this section, the 
owner or operator must comply with the requirements specified in 
paragraphs (j)(1) and (2) of this section for pressure relief devices, 
such as relief valves or rupture disks, in organic HAP gas or vapor 
service instead of the pressure relief device requirements of Sec.  
60.482-4 of this chapter, Sec.  60.482-4a of this chapter, or Sec.  
63.165, as applicable. Except as specified in paragraphs (j)(4) and (5) 
of this section, the owner or operator must also comply with the 
requirements specified in paragraph (j)(3) of this section for all 
pressure relief devices in organic HAP service.
* * * * *
    (2) * * *
    (i) If the pressure relief device does not consist of or include a 
rupture disk, conduct instrument monitoring, as specified in Sec.  
60.485(c) of this chapter, Sec.  60.485a(c) of this chapter, or Sec.  
63.180(c), as applicable, no later than 5 calendar days after the 
pressure relief device returns to organic HAP gas or vapor service 
following a pressure release to verify that the pressure relief device 
is operating with an instrument reading of less than 500 ppm.
    (ii) If the pressure relief device includes a rupture disk, either 
comply with the requirements in paragraph (j)(2)(i) of this section 
(not replacing the rupture disk) or install a replacement disk as soon 
as practicable after a pressure release, but no later than 5 calendar 
days after the pressure release. The owner or operator must conduct 
instrument monitoring, as specified in Sec.  60.485(c) of this chapter, 
Sec.  60.485a(c) of this chapter or Sec.  63.180(c), as applicable, no 
later than 5 calendar days after the pressure relief device returns to 
organic HAP gas or vapor service following a pressure release to verify 
that the pressure relief device is operating with an instrument reading 
of less than 500 ppm.
    (iii) If the pressure relief device consists only of a rupture 
disk, install a replacement disk as soon as practicable

[[Page 6083]]

after a pressure release, but no later than 5 calendar days after the 
pressure release. The owner or operator may not initiate startup of the 
equipment served by the rupture disk until the rupture disc is 
replaced. The owner or operator must conduct instrument monitoring, as 
specified in Sec.  60.485(c) of this chapter, Sec.  60.485a(c) of this 
chapter, or Sec.  63.180(c), as applicable, no later than 5 calendar 
days after the pressure relief device returns to organic HAP gas or 
vapor service following a pressure release to verify that the pressure 
relief device is operating with an instrument reading of less than 500 
ppm.
* * * * *

0
6. Section 63.655 is amended by revising paragraphs (f)(1)(iii), 
(f)(2), adding a paragraph (h)(10) subject heading, and revising 
paragraph (i)(11) introductory text to read as follows:

Sec.  63.655  Reporting and recordkeeping requirements.

* * * * *
    (f) * * *
    (1) * * *
    (iii) For miscellaneous process vents controlled by control devices 
required to be tested under Sec. Sec.  63.645 and 63.116(c), 
performance test results including the information in paragraphs 
(f)(1)(iii)(A) and (B) of this section. Results of a performance test 
conducted prior to the compliance date of this subpart can be used 
provided that the test was conducted using the methods specified in 
Sec.  63.645 and that the test conditions are representative of current 
operating conditions. If the performance test is submitted 
electronically through the EPA's Compliance and Emissions Data 
Reporting Interface (CEDRI) in accordance with Sec.  63.655(h)(9), the 
process unit(s) tested, the pollutant(s) tested, and the date that such 
performance test was conducted may be submitted in the Notification of 
Compliance Status in lieu of the performance test results. The 
performance test results must be submitted to CEDRI by the date the 
Notification of Compliance Status is submitted.
    (A) The percentage of reduction of organic HAP's or TOC, or the 
outlet concentration of organic HAP's or TOC (parts per million by 
volume on a dry basis corrected to 3 percent oxygen), determined as 
specified in Sec.  63.116(c) of subpart G of this part; and
    (B) The value of the monitored parameters specified in table 10 of 
this subpart, or a site-specific parameter approved by the permitting 
authority, averaged over the full period of the performance test.
* * * * *
    (2) If initial performance tests are required by Sec. Sec.  63.643 
through 63.653, the Notification of Compliance Status report shall 
include one complete test report for each test method used for a 
particular source. On and after February 1, 2016, for data collected 
using test methods supported by the EPA's Electronic Reporting Tool 
(ERT) as listed on the EPA's ERT website (https://www.epa.gov/electronic-reporting-air-emissions/electronic-reporting-tool-ert) at 
the time of the test, you must submit the results in accordance with 
Sec.  63.655(h)(9) by the date that you submit the Notification of 
Compliance Status, and you must include the process unit(s) tested, the 
pollutant(s) tested, and the date that such performance test was 
conducted in the Notification of Compliance Status. All other 
performance test results must be reported in the Notification of 
Compliance Status.
    (i) For additional tests performed using the same method, the 
results specified in paragraph (f)(1) of this section shall be 
submitted, but a complete test report is not required.
    (ii) A complete test report shall include a sampling site 
description, description of sampling and analysis procedures and any 
modifications to standard procedures, quality assurance procedures, 
record of operating conditions during the test, record of preparation 
of standards, record of calibrations, raw data sheets for field 
sampling, raw data sheets for field and laboratory analyses, 
documentation of calculations, and any other information required by 
the test method.
    (iii) Performance tests are required only if specified by 
Sec. Sec.  63.643 through 63.653 of this subpart. Initial performance 
tests are required for some kinds of emission points and controls. 
Periodic testing of the same emission point is not required.
* * * * *
    (h) * * *
    (10) Extensions to electronic reporting deadlines.
* * * * *
    (i) * * *
    (11) For each pressure relief device subject to the pressure 
release management work practice standards in Sec.  63.648(j)(3), the 
owner or operator shall keep the records specified in paragraphs 
(i)(11)(i) through (iii) of this section. For each pilot-operated 
pressure relief device subject to the requirements at Sec.  
63.648(j)(4)(ii), the owner or operator shall keep the records 
specified in paragraph (i)(11)(iv) of this section.
* * * * *

0
7. Section 63.660 is amended by revising paragraph (i)(2)(iii) to read 
as follows:

Sec.  63.660   Storage vessel provisions.

* * * * *
    (i) * * *
    (2) * * *
    (iii) Use a cap, blind flange, plug, or a second valve for an open-
ended valve or line following the requirements specified in Sec.  
60.482-6(a)(2), (b), and (c).
* * * * *

0
8. Section 63.670 is amended by revising paragraph (d)(2) to read as 
follows:

Sec.  63.670   Requirements for flare control devices.

* * * * *
    (d) * * *
    (2) Vtip must be less than 400 feet per second and also 
less than the maximum allowed flare tip velocity (Vmax) as 
calculated according to the following equation. The owner or operator 
shall monitor Vtip using the procedures specified in 
paragraphs (i) and (k) of this section and monitor gas composition and 
determine NHVvg using the procedures specified in paragraphs 
(j) and (l) of this section.
[GRAPHIC] [TIFF OMITTED] TR04FE20.003

Where:

Vmax = Maximum allowed flare tip velocity, ft/sec.
NHVvg = Net heating value of flare vent gas, as 
determined by paragraph (k)(4) of this section, Btu/scf.
1,212 = Constant.
850 = Constant.
* * * * *

Subpart UUU--National Emission Standards for Hazardous Air 
Pollutants for Petroleum Refineries: Catalytic Cracking Units, 
Catalytic Reforming Units, and Sulfur Recovery Units

0
9. Revise Table 4 to Subpart UUU of Part 63 to read as follows:

    Table 4 to Subpart UUU of Part 63--Requirements for Performance 
Tests for Metal HAP Emissions From Catalytic Cracking Units
    As stated in Sec. Sec.  63.1564(b)(2) and 63.1571(a)(5), you shall 
meet each requirement in the following table that applies to you.

[[Page 6084]]

----------------------------------------------------------------------------------------------------------------
For each new or existing catalytic
cracking unit catalyst regenerator      You must . . .             Using . . .             According to these
            vent . . .                                                                     requirements . . .
----------------------------------------------------------------------------------------------------------------
1. Any............................  a. Select sampling     Method 1 or 1A in appendix  Sampling sites must be
                                     port's location and    A-1 to part 60 of this      located at the outlet of
                                     the number of          chapter.                    the control device or
                                     traverse ports.                                    the outlet of the
                                                                                        regenerator, as
                                                                                        applicable, and prior to
                                                                                        any releases to the
                                                                                        atmosphere.
                                    b. Determine velocity  Method 2, 2A, 2C, 2D, or
                                     and volumetric flow    2F in appendix A-1 to
                                     rate.                  part 60 of this chapter,
                                                            or Method 2G in appendix
                                                            A-2 to part 60 of this
                                                            chapter, as applicable.
                                    c. Conduct gas         Method 3, 3A, or 3B in
                                     molecular weight       appendix A-2 to part 60
                                     analysis.              of this chapter, as
                                                            applicable.
                                    d. Measure moisture    Method 4 in appendix A-3
                                     content of the stack   to part 60 of this
                                     gas.                   chapter.
                                    e. If you use an
                                     electrostatic
                                     precipitator, record
                                     the total number of
                                     fields in the
                                     control system and
                                     how many operated
                                     during the
                                     applicable
                                     performance test.
                                    f. If you use a wet
                                     scrubber, record the
                                     total amount (rate)
                                     of water (or
                                     scrubbing liquid)
                                     and the amount
                                     (rate) of make-up
                                     liquid to the
                                     scrubber during each
                                     test run.
2. Subject to the NSPS for PM in    a. Measure PM          Method 5, 5B, or 5F (40     You must maintain a
 40 CFR 60.102 and not elect Sec.    emissions.             CFR part 60, appendix A-    sampling rate of at
  60.100(e).                                                3) to determine PM          least 0.15 dry standard
                                                            emissions and associated    cubic meters per minute
                                                            moisture content for        (dscm/min) (0.53 dry
                                                            units without wet           standard cubic feet per
                                                            scrubbers. Method 5 or 5B   minute (dscf/min)).
                                                            (40 CFR part 60, appendix
                                                            A-3) to determine PM
                                                            emissions and associated
                                                            moisture content for unit
                                                            with wet scrubber.
                                    b. Compute coke burn-  Equations 1, 2, and 3 of
                                     off rate and PM        Sec.   63.1564 (if
                                     emission rate (lb/     applicable).
                                     1,000 lb of coke
                                     burn-off).
                                    c. Measure opacity of  Continuous opacity          You must collect opacity
                                     emissions.             monitoring system.          monitoring data every 10
                                                                                        seconds during the
                                                                                        entire period of the
                                                                                        Method 5, 5B, or 5F
                                                                                        performance test and
                                                                                        reduce the data to 6-
                                                                                        minute averages.
3. Subject to the NSPS for PM in    a. Measure PM          Method 5, 5B, or 5F (40     You must maintain a
 40 CFR 60.102a(b)(1) or elect       emissions.             CFR part 60, appendix A-    sampling rate of at
 Sec.   60.100(e), electing the PM                          3) to determine PM          least 0.15 dscm/min
 for coke burn-off limit.                                   emissions and associated    (0.53 dscf/min).
                                                            moisture content for
                                                            units without wet
                                                            scrubbers. Method 5 or 5B
                                                            (40 CFR part 60, appendix
                                                            A-3) to determine PM
                                                            emissions and associated
                                                            moisture content for unit
                                                            with wet scrubber.
                                    b. Compute coke burn-  Equations 1, 2, and 3 of
                                     off rate and PM        Sec.   63.1564 (if
                                     emission rate (lb/     applicable).
                                     1,000 lb of coke
                                     burn-off).

[[Page 6085]]

 
                                    c. Establish site-     Continuous opacity          If you elect to comply
                                     specific limit if      monitoring system.          with the site-specific
                                     you use a COMS.                                    opacity limit in Sec.
                                                                                        63.1564(b)(4)(i), you
                                                                                        must collect opacity
                                                                                        monitoring data every 10
                                                                                        seconds during the
                                                                                        entire period of the
                                                                                        Method 5, 5B, or 5F
                                                                                        performance test. For
                                                                                        site specific opacity
                                                                                        monitoring, reduce the
                                                                                        data to 6-minute
                                                                                        averages; determine and
                                                                                        record the average
                                                                                        opacity for each test
                                                                                        run; and compute the
                                                                                        site-specific opacity
                                                                                        limit using Equation 4
                                                                                        of Sec.   63.1564.
4. Subject to the NSPS for PM in    a. Measure PM          Method 5, 5B, or 5F (40     You must maintain a
 40 CFR 60.102a(b)(1) or elect       emissions.             CFR part 60, appendix A-    sampling rate of at
 Sec.   60.100(e).                                          3) to determine PM          least 0.15 dscm/min
                                                            emissions and associated    (0.53 dscf/min).
                                                            moisture content for
                                                            units without wet
                                                            scrubbers. Method 5 or 5B
                                                            (40 CFR part 60, appendix
                                                            A-3) to determine PM
                                                            emissions and associated
                                                            moisture content for unit
                                                            with wet scrubber.
5. Option 1a: Elect NSPS subpart J  See item 2 of this
 requirements for PM per coke burn-  table.
 off limit, not subject to the
 NSPS for PM in 40 CFR 60.102 or
 60.102a(b)(1).
6. Option 1b: Elect NSPS subpart    See item 3 of this
 Ja requirements for PM per coke     table.
 burn-off limit, not subject to
 the NSPS for PM in 40 CFR 60.102
 or 60.102a(b)(1).
7. Option 1c: Elect NSPS            See item 4 of this
 requirements for PM                 table.
 concentration, not subject to the
 NSPS for PM in 40 CFR 60.102 or
 60.102a(b)(1).
8. Option 2: PM per coke burn-off   See item 3 of this
 limit, not subject to the NSPS      table.
 for PM in 40 CFR 60.102 or
 60.102a(b)(1).
9. Option 3: Ni lb/hr limit, not    a. Measure             Method 29 (40 CFR part 60,
 subject to the NSPS for PM in 40    concentration of Ni.   appendix A-8) Equation 5
 CFR 60.102 or 60.102a(b)(1).       b. Compute Ni           of Sec.   63.1564.
                                     emission rate (lb/
                                     hr).
                                    c. Determine the       XRF procedure in appendix   You must obtain 1 sample
                                     equilibrium catalyst   A to this subpart; \1\ or   for each of the 3 test
                                     Ni concentration.      EPA Method 6010B or 6020    runs; determine and
                                                            or EPA Method 7520 or       record the equilibrium
                                                            7521 in SW-8462; or an      catalyst Ni
                                                            alternative to the SW-846   concentration for each
                                                            method satisfactory to      of the 3 samples; and
                                                            the Administrator.          you may adjust the
                                                                                        laboratory results to
                                                                                        the maximum value using
                                                                                        Equation 1 of Sec.
                                                                                        63.1571, if applicable.
                                    d. If you use a        i. Equations 6 and 7 of     (1) You must collect
                                     continuous opacity     Sec.   63.1564 using data   opacity monitoring data
                                     monitoring system,     from continuous opacity     every 10 seconds during
                                     establish your site-   monitoring system, gas      the entire period of the
                                     specific Ni            flow rate, results of       initial Ni performance
                                     operating limit.       equilibrium catalyst Ni     test; reduce the data to
                                                            concentration analysis,     6-minute averages; and
                                                            and Ni emission rate from   determine and record the
                                                            Method 29 test.             average opacity from all
                                                                                        the 6-minute averages
                                                                                        for each test run.
                                                                                       (2) You must collect gas
                                                                                        flow rate monitoring
                                                                                        data every 15 minutes
                                                                                        during the entire period
                                                                                        of the initial Ni
                                                                                        performance test;
                                                                                        measure the gas flow as
                                                                                        near as practical to the
                                                                                        continuous opacity
                                                                                        monitoring system; and
                                                                                        determine and record the
                                                                                        hourly average actual
                                                                                        gas flow rate for each
                                                                                        test run.

[[Page 6086]]

 
10. Option 4: Ni per coke burn-off  a. Measure             Method 29 (40 CFR part 60,
 limit, not subject to the NSPS      concentration of Ni.   appendix A-8). Equations
 for PM in 40 CFR 60.102 or         b. Compute Ni           1 and 8 of Sec.   63.1564.
 60.102a(b)(1).                      emission rate (lb/
                                     1,000 lb of coke
                                     burn-off).
                                    c. Determine the       See item 9.c. of this       You must obtain 1 sample
                                     equilibrium catalyst   table.                      for each of the 3 test
                                     Ni concentration.                                  runs; determine and
                                                                                        record the equilibrium
                                                                                        catalyst Ni
                                                                                        concentration for each
                                                                                        of the 3 samples; and
                                                                                        you may adjust the
                                                                                        laboratory results to
                                                                                        the maximum value using
                                                                                        Equation 2 of Sec.
                                                                                        63.1571, if applicable.
                                    d. If you use a        i. Equations 9 and 10 of    (1) You must collect
                                     continuous opacity     Sec.   63.1564 with data    opacity monitoring data
                                     monitoring system,     from continuous opacity     every 10 seconds during
                                     establish your site-   monitoring system, coke     the entire period of the
                                     specific Ni            burn-off rate, results of   initial Ni performance
                                     operating limit.       equilibrium catalyst Ni     test; reduce the data to
                                                            concentration analysis,     6-minute averages; and
                                                            and Ni emission rate from   determine and record the
                                                            Method 29 test.             average opacity from all
                                                                                        the 6-minute averages
                                                                                        for each test run.
                                                                                       (2) You must collect gas
                                                                                        flow rate monitoring
                                                                                        data every 15 minutes
                                                                                        during the entire period
                                                                                        of the initial Ni
                                                                                        performance test;
                                                                                        measure the gas flow
                                                                                        rate as near as
                                                                                        practical to the
                                                                                        continuous opacity
                                                                                        monitoring system; and
                                                                                        determine and record the
                                                                                        hourly average actual
                                                                                        gas flow rate for each
                                                                                        test run.
                                    e. Record the
                                     catalyst addition
                                     rate for each test
                                     and schedule for the
                                     10-day period prior
                                     to the test.
11. If you elect item 5 Option 1b   a. Establish each      Data from the continuous
 in Table 1, item 7 Option 2 in      operating limit in     parameter monitoring
 Table 1, item 8 Option 3 in Table   Table 2 of this        systems and applicable
 1, or item 9 Option 4 in Table 1    subpart that applies   performance test methods.
 of this subpart and you use         to you.
 continuous parameter monitoring
 systems.
                                    b. Electrostatic       i. Data from the            (1) You must collect gas
                                     precipitator or wet    continuous parameter        flow rate monitoring
                                     scrubber: Gas flow     monitoring systems and      data every 15 minutes
                                     rate.                  applicable performance      during the entire period
                                                            test methods.               of the initial
                                                                                        performance test;
                                                                                        determine and record the
                                                                                        average gas flow rate
                                                                                        for each test run.
                                                                                       (2) You must determine
                                                                                        and record the 3-hr
                                                                                        average gas flow rate
                                                                                        from the test runs.
                                                                                        Alternatively, before
                                                                                        August 1, 2017, you may
                                                                                        determine and record the
                                                                                        maximum hourly average
                                                                                        gas flow rate from all
                                                                                        the readings.
                                    c. Electrostatic       i. Data from the            (1) You must collect
                                     precipitator: Total    continuous parameter        voltage, current, and
                                     power (voltage and     monitoring systems and      secondary current
                                     current) and           applicable performance      monitoring data every 15
                                     secondary current.     test methods.               minutes during the
                                                                                        entire period of the
                                                                                        performance test; and
                                                                                        determine and record the
                                                                                        average voltage,
                                                                                        current, and secondary
                                                                                        current for each test
                                                                                        run. Alternatively,
                                                                                        before August 1, 2017,
                                                                                        you may collect voltage
                                                                                        and secondary current
                                                                                        (or total power input)
                                                                                        monitoring data every 15
                                                                                        minutes during the
                                                                                        entire period of the
                                                                                        initial performance
                                                                                        test.
                                                                                       (2) You must determine
                                                                                        and record the 3-hr
                                                                                        average total power to
                                                                                        the system for the test
                                                                                        runs and the 3-hr
                                                                                        average secondary
                                                                                        current from the test
                                                                                        runs. Alternatively,
                                                                                        before August 1, 2017,
                                                                                        you may determine and
                                                                                        record the minimum
                                                                                        hourly average voltage
                                                                                        and secondary current
                                                                                        (or total power input)
                                                                                        from all the readings.

[[Page 6087]]

 
                                    d. Electrostatic       Results of analysis for     You must determine and
                                     precipitator or wet    equilibrium catalyst Ni     record the average
                                     scrubber:              concentration.              equilibrium catalyst Ni
                                     Equilibrium catalyst                               concentration for the 3
                                     Ni concentration.                                  runs based on the
                                                                                        laboratory results. You
                                                                                        may adjust the value
                                                                                        using Equation 1 or 2 of
                                                                                        Sec.   63.1571 as
                                                                                        applicable.
                                    e. Wet scrubber:       i. Data from the            (1) You must collect
                                     Pressure drop (not     continuous parameter        pressure drop monitoring
                                     applicable to non-     monitoring systems and      data every 15 minutes
                                     venturi scrubber of    applicable performance      during the entire period
                                     jet ejector design).   test methods.               of the initial
                                                                                        performance test; and
                                                                                        determine and record the
                                                                                        average pressure drop
                                                                                        for each test run.
                                                                                       (2) You must determine
                                                                                        and record the 3-hr
                                                                                        average pressure drop
                                                                                        from the test runs.
                                                                                        Alternatively, before
                                                                                        August 1, 2017, you may
                                                                                        determine and record the
                                                                                        minimum hourly average
                                                                                        pressure drop from all
                                                                                        the readings.
                                    f. Wet scrubber:       i. Data from the            (1) You must collect gas
                                     Liquid-to-gas ratio.   continuous parameter        flow rate and total
                                                            monitoring systems and      water (or scrubbing
                                                            applicable performance      liquid) flow rate
                                                            test methods.               monitoring data every 15
                                                                                        minutes during the
                                                                                        entire period of the
                                                                                        initial performance
                                                                                        test; determine and
                                                                                        record the average gas
                                                                                        flow rate for each test
                                                                                        run; and determine the
                                                                                        average total water (or
                                                                                        scrubbing liquid) flow
                                                                                        for each test run.
                                                                                       (2) You must determine
                                                                                        and record the hourly
                                                                                        average liquid-to-gas
                                                                                        ratio from the test
                                                                                        runs. Alternatively,
                                                                                        before August 1, 2017,
                                                                                        you may determine and
                                                                                        record the hourly
                                                                                        average gas flow rate
                                                                                        and total water (or
                                                                                        scrubbing liquid) flow
                                                                                        rate from all the
                                                                                        readings.
                                                                                       (3) You must determine
                                                                                        and record the 3-hr
                                                                                        average liquid-to-gas
                                                                                        ratio. Alternatively,
                                                                                        before August 1, 2017,
                                                                                        you may determine and
                                                                                        record the minimum
                                                                                        liquid-to-gas ratio.
                                    g. Alternative         i. Data from the            (1) You must collect air
                                     procedure for gas      continuous parameter        flow rate monitoring
                                     flow rate.             monitoring systems and      data or determine the
                                                            applicable performance      air flow rate using
                                                            test methods.               control room
                                                                                        instrumentation every 15
                                                                                        minutes during the
                                                                                        entire period of the
                                                                                        initial performance
                                                                                        test.
                                                                                       (2) You must determine
                                                                                        and record the 3-hr
                                                                                        average rate of all the
                                                                                        readings from the test
                                                                                        runs. Alternatively,
                                                                                        before August 1, 2017,
                                                                                        you may determine and
                                                                                        record the hourly
                                                                                        average rate of all the
                                                                                        readings.
                                                                                       (3) You must determine
                                                                                        and record the maximum
                                                                                        gas flow rate using
                                                                                        Equation 1 of Sec.
                                                                                        63.1573.
----------------------------------------------------------------------------------------------------------------
\1\ Determination of Metal Concentration on Catalyst Particles (Instrumental Analyzer Procedure).
\2\ EPA Method 6010B, Inductively Coupled Plasma-Atomic Emission Spectrometry, EPA Method 6020, Inductively
  Coupled Plasma-Mass Spectrometry, EPA Method 7520, Nickel Atomic Absorption, Direct Aspiration, and EPA Method
  7521, Nickel Atomic Absorption, Direct Aspiration are included in ``Test Methods for Evaluating Solid Waste,
  Physical/Chemical Methods,'' EPA Publication SW-846, Revision 5 (April 1998). The SW-846 and Updates (document
  number 955-001-00000-1) are available for purchase from the Superintendent of Documents, U.S. Government
  Publishing Office, Washington, DC 20402, (202) 512-1800; and from the National Technical Information Services
  (NTIS), 5285 Port Royal Road, Springfield, VA 22161, (703) 487-4650. Copies may be inspected at the EPA Docket
  Center, William Jefferson Clinton (WJC) West Building (Air Docket), Room 3334, 1301 Constitution Ave. NW,
  Washington, DC; or at the Office of the Federal Register, 800 North Capitol Street NW, Suite 700, Washington,
  DC.

[FR Doc. 2020-01108 Filed 2-3-20; 8:45 am]
 BILLING CODE 6560-50-P