Rule2024-04629

National Emission Standards for Hazardous Air Pollutants: Gasoline Distribution Technology Reviews and New Source Performance Standards Review for Bulk Gasoline Terminals

Primary source

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Published
May 8, 2024
Effective
July 8, 2024

Issuing agencies

Environmental Protection Agency

Abstract

The Environmental Protection Agency (EPA) is finalizing the technology reviews (TR) conducted for the national emission standards for hazardous air pollutants (NESHAP) for gasoline distribution facilities and the review of the new source performance standards (NSPS) for bulk gasoline terminals pursuant to the requirements of the Clean Air Act (CAA). The final NESHAP amendments include revised requirements for storage vessels, loading operations, and equipment to reflect cost-effective developments in practices, processes, or controls. The final NSPS reflect the best system of emission reduction for loading operations and equipment leaks. In addition, the EPA is: finalizing revisions related to emissions during periods of startup, shutdown, and malfunction (SSM); adding requirements for electronic reporting; revising monitoring and operating requirements for control devices; and making other minor technical improvements. The EPA estimates that this final action will reduce hazardous air pollutant emissions from gasoline distribution facilities by over 2,200 tons per year (tpy) and volatile organic compound (VOC) emissions by 45,400 tpy.

Full Text

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[Federal Register Volume 89, Number 90 (Wednesday, May 8, 2024)]
[Rules and Regulations]
[Pages 39304-39390]
From the Federal Register Online via the Government Publishing Office [<a href="http://www.gpo.gov">www.gpo.gov</a>]
[FR Doc No: 2024-04629]



[[Page 39303]]

Vol. 89

Wednesday,

No. 90

May 8, 2024

Part VI





Environmental Protection Agency





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40 CFR Parts 60 and 63





National Emission Standards for Hazardous Air Pollutants: Gasoline 
Distribution Technology Reviews and New Source Performance Standards 
Review for Bulk Gasoline Terminals; Final Rule

Federal Register / Vol. 89 , No. 90 / Wednesday, May 8, 2024 / Rules 
and Regulations

[[Page 39304]]


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ENVIRONMENTAL PROTECTION AGENCY

40 CFR Parts 60 and 63

[EPA-HQ-OAR-2020-0371; FRL-8202-02-OAR]
RIN 2060-AU97


National Emission Standards for Hazardous Air Pollutants: 
Gasoline Distribution Technology Reviews and New Source Performance 
Standards Review for Bulk Gasoline Terminals

AGENCY: Environmental Protection Agency (EPA).

ACTION: Final rule.

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SUMMARY: The Environmental Protection Agency (EPA) is finalizing the 
technology reviews (TR) conducted for the national emission standards 
for hazardous air pollutants (NESHAP) for gasoline distribution 
facilities and the review of the new source performance standards 
(NSPS) for bulk gasoline terminals pursuant to the requirements of the 
Clean Air Act (CAA). The final NESHAP amendments include revised 
requirements for storage vessels, loading operations, and equipment to 
reflect cost-effective developments in practices, processes, or 
controls. The final NSPS reflect the best system of emission reduction 
for loading operations and equipment leaks. In addition, the EPA is: 
finalizing revisions related to emissions during periods of startup, 
shutdown, and malfunction (SSM); adding requirements for electronic 
reporting; revising monitoring and operating requirements for control 
devices; and making other minor technical improvements. The EPA 
estimates that this final action will reduce hazardous air pollutant 
emissions from gasoline distribution facilities by over 2,200 tons per 
year (tpy) and volatile organic compound (VOC) emissions by 45,400 tpy.

DATES: The final rule is effective July 8, 2024.

ADDRESSES: The EPA has established a docket for this action under 
Docket ID No. EPA-HQ-OAR-2020-0371. All documents in the docket are 
listed on the <a href="https://www.regulations.gov/">https://www.regulations.gov/</a> website. Although listed, 
some information is not publicly available, e.g., Confidential Business 
Information (CBI) 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. Publicly available docket materials are available electronically 
through <a href="https://www.regulations.gov/">https://www.regulations.gov/</a>.

FOR FURTHER INFORMATION CONTACT: For questions about this final action, 
contact U.S. EPA, Attn: Ms. Jennifer Caparoso, Mail Drop: E143-01, 109 
T.W. Alexander Drive, P.O. Box 12055, RTP, NC 27711; telephone number: 
(919) 541-4063; and email address: <a href="/cdn-cgi/l/email-protection#0f6c6e7f6e7d607c6021656a616166696a7d4f6a7f6e21686079"><span class="__cf_email__" data-cfemail="80e3e1f0e1f2eff3efaeeae5eeeee9e6e5f2c0e5f0e1aee7eff6">[email&#160;protected]</span></a>.

SUPPLEMENTARY INFORMATION: 
    Preamble acronyms and abbreviations. Throughout this document the 
use of ``we,'' ``us,'' or ``our'' is intended to refer to the EPA. The 
EPA uses multiple acronyms and terms in this preamble. While this list 
may not be exhaustive, to ease the reading of this preamble and for 
reference purposes, the EPA defines the following terms and acronyms 
here:

AVO audio, visual, or olfactory
BACT best available control technology
BSER best system of emission reduction
CAA Clean Air Act
CDX Central Data Exchange
CEDRI Compliance and Emissions Data Reporting Interface
CEMS continuous emission monitoring system
CFR Code of Federal Regulations
CO carbon monoxide
CO<INF>2</INF> carbon dioxide
CPMS continuous parametric monitoring system
EAV equivalent annual value
EJ environmental justice
E.O. Executive Order
EPA Environmental Protection Agency
ERT Electronic Reporting Tool
FR Federal Register
GACT generally available control technology
HAP hazardous air pollutant(s)
ICR information collection request
km kilometer
LAER lowest achievable emission rate
LDAR leak detection and repair
LEL lower explosive limit
MACT maximum achievable control technology
mg/L milligrams per liter
mph miles per hour
NAICS North American Industry Classification System
NESHAP national emission standards for hazardous air pollutants
NHV<INF>cz</INF> combustion zone net heating value
NHV<INF>dil</INF> net heating value dilution
NO<INF>X</INF> nitrogen oxides
NSPS new source performance standards
O<INF>3</INF> ozone
OGI optical gas imaging
OMB Office of Management and Budget
ppmv parts per million volume
psig pounds per square inch gauge
PRA Paperwork Reduction Act
PV present value
RACT reasonably available control technology
RFA Regulatory Flexibility Act
RIA regulatory impact analysis
RTR risk and technology review
SO<INF>2</INF> sulfur dioxide
SSM startup, shutdown, and malfunction
TOC total organic carbon
tpy tons per year
TR technology review
U.S. United States
U.S.C. United States Code
VOC volatile organic compound(s)
VRU vapor recovery unit

    Background information. On June 10, 2022, the EPA proposed 
revisions to both the major source and area source Gasoline 
Distribution NESHAP and the Bulk Gasoline Terminals NSPS based on the 
TR and NSPS review. In this action, the EPA is finalizing decisions and 
revisions for these rules. The EPA summarized some of the more 
significant comments we timely received regarding the proposed rules 
and provides responses in this preamble. A summary of all other public 
comments on the proposals and the EPA's responses to those comments is 
available in National Emission Standards for Hazardous Air Pollutants 
for Gasoline Distribution Facilities and New Source Performance 
Standards for Bulk Gasoline Terminals, Background Information for Final 
Amendments, Summary of Public Comments and Responses, Docket ID No. 
EPA-HQ-OAR-2020-0371. ``Track changes'' versions of the regulatory 
language that incorporates the changes in these rules are available in 
the docket.
    Organization of this document. The information in this preamble is 
organized as follows:

I. General Information
    A. Executive Summary
    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 Review
II. Background
    A. What is the statutory authority for this action?
    B. What are the source categories regulated in this final 
action?
    C. What changes were proposed for the gasoline distribution 
NESHAP and for the bulk gasoline terminals NSPS in the June 10, 
2022, proposal?
    D. What outreach was conducted following the proposal?
III. What is included in these final rules and what is the rationale 
for the final decisions and amendments?
    A. What are the final rule amendments based on the technology 
reviews for the gasoline distribution NESHAP and NSPS review for 
bulk gasoline terminals?
    B. Other Actions the EPA is Finalizing and the Rationale
    C. What are the effective and compliance dates of the standards?
IV. Summary of Cost, Environmental, and Economic Impacts and 
Additional Analyses Conducted
    A. What are the affected facilities?

[[Page 39305]]

    B. What are the air quality impacts?
    C. What are the cost impacts?
    D. What are the economic impacts?
    E. What are the benefits?
    F. What analysis of environmental justice did the EPA conduct?
V. Statutory and Executive Order Reviews
    A. Executive Order 12866: Regulatory Planning and Review and 
Executive Order 14094: Modernizing Regulatory Review
    B. Paperwork Reduction Act (PRA)
    C. Regulatory Flexibility Act (RFA)
    D. Unfunded Mandates Reform Act of 1995 (UMRA)
    E. Executive Order 13132: Federalism
    F. Executive Order 13175: Consultation and Coordination with 
Indian Tribal Governments
    G. Executive Order 13045: Protection of Children from 
Environmental Health Risks and Safety Risks
    H. Executive Order 13211: Actions Concerning Regulations that 
Significantly Affect Energy Supply, Distribution, or Use
    I. National Technology Transfer and Advancement Act (NTTAA)
    J. Executive Order 12898: Federal Actions to Address 
Environmental Justice in Minority Populations and Low-Income 
Populations and Executive Order 14096: Revitalizing Our Nation's 
Commitment to Environmental Justice for All
    K. Congressional Review Act (CRA)

I. General Information

A. Executive Summary

1. Purpose of the Regulatory Action
    The source categories that are the subject of this final action are 
Gasoline Distribution regulated under 40 CFR part 63, subparts R and 
BBBBBB, and Bulk Gasoline Terminals \1\ regulated under 40 CFR part 60, 
subparts XX and XXa. The EPA set maximum achievable control technology 
(MACT) standards for the gasoline distribution major source category in 
1994 and conducted the residual risk and technology review (RTR) in 
2006. The sources affected by the major source NESHAP for the gasoline 
distribution source category (40 CFR part 63, subpart R) are bulk 
gasoline terminals and pipeline breakout stations. The EPA set 
generally available control technology (GACT) standards for the 
gasoline distribution area source category in 2008. The sources 
affected by the area source NESHAP for the gasoline distribution source 
category (40 CFR part 63, subpart BBBBBB) are bulk gasoline terminals, 
bulk gasoline plants, and pipeline facilities. The EPA set the first 
NSPS for bulk gasoline terminals in 1983. Bulk gasoline terminals that 
commenced construction or modification after December 17, 1980, and on 
or before June 10, 2022, are regulated under the NSPS codified at 40 
CFR part 60, subpart XX. Bulk gasoline terminals that commenced 
construction or modification after June 10, 2022, will be regulated 
under the NSPS codified at 40 CFR part 60, subpart XXa.
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    \1\ Petroleum Transportation and Marketing is the listed source 
category. Bulk Gasoline Terminals are the affected facilities 
regulated by the NSPS addressing the Petroleum Transportation and 
Marketing source category.
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    The statutory authority for these final rulemakings is sections 111 
and 112 of the CAA. Section 111(b)(1)(B) of the CAA requires the EPA to 
``at least every 8 years review and, if appropriate, revise'' the NSPS. 
Section 111(a)(1) of the CAA provides that performance standards are to 
``reflect the degree of emission limitation achievable through the 
application of the best system of emission reduction which (taking into 
account the cost of achieving such reduction and any nonair quality 
health and environmental impact and energy requirements) the 
Administrator determines has been adequately demonstrated.'' We refer 
to this level of control as the best system of emission reduction or 
``BSER.'' Section 112(d)(6) of the CAA requires the EPA to review 
standards promulgated under CAA section 112(d) and revise them ``as 
necessary (taking into account developments in practices, processes, 
and control technologies)'' no less often than every 8 years following 
promulgation of those standards. This is referred to as a ``technology 
review.''
    The NSPS for Bulk Gasoline Terminals and the amendments to the 
NESHAP for Gasoline Distribution facilities finalized in this action 
fulfill the Agency's requirements, respectively, to review and, if 
appropriate, revise the NSPS and to review and revise as necessary the 
NESHAP at least every 8 years.
2. Summary of the Major Provisions of the Regulatory Action in Question
a. NESHAP Subpart R
    The EPA is finalizing the requirement of a graduated vapor 
tightness certification from 0.5 to 1.25 inches of water pressure drop 
over a 5-minute period, depending on the cargo tank compartment size 
for gasoline cargo tanks. The EPA is also finalizing the requirement of 
fitting controls for external floating roof tanks consistent with the 
requirements in 40 CFR part 60, subpart Kb (NSPS subpart Kb). In 
addition, the EPA is finalizing the requirement of semiannual 
instrument monitoring for equipment leaks at major source gasoline 
distribution facilities.
b. NESHAP Subpart BBBBBB
    The EPA is finalizing an area source emission limit of 35 
milligrams of total organic carbon (TOC) per liter of gasoline loaded 
(mg/L) at large bulk gasoline terminals and vapor balancing \2\ 
requirements for loading storage vessels and gasoline cargo tanks at 
bulk gasoline plants with actual throughput of 4,000 gallons per day or 
more. The EPA is also finalizing the requirement of a graduated vapor 
tightness certification from 0.5 to 1.25 inches of water pressure drop 
over a 5-minute period, depending on the cargo tank compartment size 
for gasoline cargo tanks. Additionally, the EPA is finalizing the 
requirement of fitting controls for external floating roof tanks 
consistent with the requirements in NSPS subpart Kb. Also, the EPA is 
finalizing the requirement of annual instrument monitoring for 
equipment leaks at area source gasoline distribution facilities.
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    \2\ When using a vapor balancing system, displaced vapors from a 
cargo tank are captured and routed through piping back to a storage 
vessel or vice-a-versa.
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c. NSPS Subpart XXa
    The EPA is finalizing a new NSPS subpart XXa applicable to affected 
facilities that commence construction, modification, or reconstruction 
after June 10, 2022. For loading operations, the EPA is finalizing 
standards of performance for VOC that require new facilities to meet a 
1.0 mg/L TOC emission limit and modified and reconstructed facilities 
to meet a 10 mg/L TOC emission limit. The EPA is also finalizing the 
requirement for gasoline cargo tanks of a graduated vapor tightness 
certification from 0.5 to 1.25 inches of water pressure drop over a 5-
minute period, depending on the cargo tank compartment size. In 
addition, the EPA is finalizing the requirement of quarterly instrument 
monitoring for equipment leaks.
3. Costs and Benefits
    In accordance with Executive Order (E.O.) 12866 and 13563, the 
guidelines of the Office of Management and Budget (OMB) Circular A-4, 
and the EPA's Guidelines for Preparing Economic Analyses, the EPA 
prepared a Regulatory Impact Analysis (RIA) for the proposal of the 
rules included in this action. The RIA analyzed the benefits and costs 
associated with the projected emissions reductions under the proposed 
requirements, a less stringent set of requirements, and a more 
stringent set of requirements. Prior to the amendments made by E.O. 
14094, the proposal of the area source NESHAP

[[Page 39306]]

rule was significant under E.O. 12866, section 3(f)(1) due to its 
likely annual effect on the economy of $100 million or more in any one 
year on the economy, a sector of the economy, productivity, 
competition, jobs, the environment, public health or safety, or State, 
local, or Tribal governments or communities. Specifically, monetized 
health benefits from projected VOC reductions associated with the 
proposed area source NESHAP rule amendments exceeded $100 million per 
year.
    On April 6, 2023, President Biden issued E.O. 14094, Modernizing 
Regulatory Review, which increased the annual effect threshold for 
significance under E.O. 12866, section 3(f)(1) from $100 million to 
$200 million. This final action is significant under E.O. 12866, 
section 3(f)(1) as amended by E.O. 14094. Accordingly, the EPA has 
prepared a Regulatory Impact Analysis (RIA).
    The EPA projected the emissions reductions, costs, and benefits 
that may result from the rules included in this final action, which are 
presented in detail in the RIA. We present these results for each of 
the three rules included in this final action, and also cumulatively. 
The RIA focuses on the elements of the final action that are likely to 
result in quantifiable cost or emissions changes compared to a baseline 
without the final NESHAP and NSPS amendments. We estimated the cost, 
emissions, and benefit impacts for the 2027 to 2041 period. We also 
show the present value (PV) and equivalent annual value (EAV) of costs, 
benefits, and net benefits of this action in 2021 dollars. The year 
2019 was used as the base year in the cost analyses at proposal. 
However, based on comments received, we updated our analyses to use 
2021 as the base year.
    The EPA also updated costs and emissions impacts in the RIA to 
incorporate changes to the economic environment since the proposal. 
Specifically, the interest rate used to annualize capital costs rose 
from 3.25 percent to 7.75 percent to reflect changes in the bank prime 
rate, the VOC recovery credit used to value gasoline product recovery 
was updated to reflect the 2021 wholesale price of gasoline, and the 
dollar-year was updated from 2019 to 2021 to reflect recent 
inflation.\3\
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    \3\ The EPA used the wholesale price of gasoline in this 
analysis to provide a focus on the rulemaking's cost impacts to 
affected firms, including the impact of product recovery upon the 
cost to these firms. Use of the consumer price of gasoline would 
introduce market interactions that may make analysis of product 
recovery more difficult to estimate given passthrough of costs by 
firms to consumers. More explanation on the use of wholesale price 
of gasoline is found in Chapter 3 of the RIA.
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    The initial analysis year in the RIA is 2027, as we assume the 
large majority of impacts associated with the final action will begin 
in that year. The most significant impacts of this final action are due 
to the regulation of existing sources under the major and area source 
NESHAP rules. These two rules, NESHAP subparts R and BBBBBB, require 
compliance with the existing source standards 3 years after the 
promulgation date of these final rules. As a result, compliance with 
the standards for existing sources will occur in 2027. The final 
analysis year is 2041, which allows us to present 15 years of projected 
impacts after all three of these rules are assumed to take effect.
    The cost analysis presented in the RIA reflects a nationwide 
engineering analysis of compliance cost and emissions reductions, of 
which there are two main components. The first component is a set of 
representative or model plants for each regulated facility, segment, 
and control option. The characteristics of a model plant include 
typical equipment, operating characteristics, and representative 
factors including baseline emissions and the costs, emissions 
reductions, and product recovery of gasoline resulting from each 
control option. The second component is a set of projections of data 
for affected facilities, distinguished by vintage, year, and other 
necessary attributes (e.g., precise content of material in storage 
vessels). Impacts are calculated by setting parameters on how and when 
affected facilities are assumed to respond to a particular regulatory 
regime, multiplying data by model plant cost and emissions estimates, 
differencing from the baseline scenario, and then summing to the 
desired level of aggregation. In addition to emissions reductions, some 
control options result in recovered gasoline, which can then be sold 
where possible. Where applicable, we present projected compliance costs 
with and without the projected revenues from product recovery.
    The EPA expects health benefits as a result of the emissions 
reductions projected under this final action. We expect that hazardous 
air pollutants (HAP) emission reductions will improve health and 
welfare associated with those affected by these emissions. In addition, 
the EPA expects that VOC emission reductions that will occur concurrent 
with the reductions of HAP emissions will improve air quality and are 
likely to improve health and welfare associated with reduced exposure 
to ozone, particulate matter with a diameter less than 2.5 microns 
(PM<INF>2.5</INF>), and HAP. The EPA expects disbenefits from secondary 
increases of carbon dioxide (CO<INF>2</INF>), nitrogen oxides 
(NO<INF>X</INF>), sulfur dioxide (SO<INF>2</INF>), and carbon monoxide 
(CO) emissions associated with the control options included in the cost 
analysis. The benefits of reduced premature mortality and morbidity 
associated with reduced exposure to VOC emissions and climate 
disbenefits associated with increased CO<INF>2</INF> emissions have 
been monetized for this final action. Our discussion of both the 
benefits and disbenefits, monetized and non-monetized, associated with 
this action are included in chapter 4 of the RIA.
    Tables 1 through 3 of this document present the emission changes 
and the PV and EAV of the projected monetized benefits, compliance 
costs, and net benefits over the 2027 to 2041 period under the final 
action for each subpart. Table 4 of this document presents the same 
results for the cumulative impact of these rulemakings. Climate 
disbenefits are discounted using a 3 percent social discount rate. All 
other discounting of impacts presented uses social discount rates of 3 
and 7 percent.

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B. Does this action apply to me?

    The source categories that are the subject of this final action are 
Gasoline Distribution regulated under 40 CFR part 63, subparts R and 
BBBBBB, and Bulk Gasoline Terminals regulated under 40 CFR part 60, 
subparts XX and XXa. The 2022 North American Industry Classification 
System (NAICS) codes for the gasoline distribution industry are 324110, 
493190, 486910, and 424710. The NAICS codes are not intended to be 
exhaustive but rather to serve as a guide for readers regarding 
entities likely to be affected by this final action. The NSPS codified 
in 40 CFR part 60, subpart XXa, are directly applicable to affected 
facilities that begin construction, reconstruction, or modification 
after June 10, 2022. If you have any questions regarding the 
applicability of these rules to a particular entity, you should 
carefully examine the applicability criteria found in the appropriate 
NESHAP and NSPS, and consult with the person listed in the FOR FURTHER 
INFORMATION CONTACT section of this preamble, your State air pollution 
control agency with delegated authority, or your EPA Regional Office.

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

    In addition to being available in the docket, an electronic copy of 
this final action is available on the internet at <a href="https://www.epa.gov/stationary-sources-air-pollution/gasoline-distribution-mact-and-gact-national-emission-standards">https://www.epa.gov/stationary-sources-air-pollution/gasoline-distribution-mact-and-gact-national-emission-standards</a>. Following publication in the Federal 
Register, the EPA will post the Federal Register version and key 
technical documents at this same website.
    Additional information is available on the RTR website at <a href="https://www.epa.gov/stationary-sources-air-pollution/risk-and-technology-review-national-emissions-standards-hazardous">https://www.epa.gov/stationary-sources-air-pollution/risk-and-technology-review-national-emissions-standards-hazardous</a>. This information 
includes an overview of the RTR program and links to project websites 
for the RTR source categories.

D. Judicial Review and Administrative Review

    Under CAA section 307(b)(1), judicial review of this final action 
is available only by filing a petition for review in the United States 
Court of Appeals for the District of Columbia Circuit by July 8, 2024. 
Under CAA section 307(b)(2), the requirements established by these 
final rules may not be challenged separately in any civil or criminal 
proceedings brought by the EPA to enforce the requirements.
    Section 307(d)(7)(B) of the CAA further provides that ``[o]nly an 
objection to a rule or procedure which was raised with reasonable 
specificity during the period for public comment (including any public 
hearing) may be raised during judicial review.'' This section also 
provides a mechanism for the EPA to reconsider the rules, ``[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. Environmental Protection Agency, Room 3000, WJC 
West Building, 1200 Pennsylvania Ave. NW, Washington, DC 20460, with a 
copy to both the person 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. 
Environmental Protection Agency, 1200 Pennsylvania Ave. NW, Washington, 
DC 20460.

II. Background

A. What is the statutory authority for this action?

1. NESHAP
    The statutory authority for this action is provided by CAA sections 
112 and 301, as amended (42 U.S.C. 7401 et seq.). Section 112 of the 
CAA establishes a two-stage regulatory process to develop standards for 
HAP from stationary sources. Generally, the first stage involves 
establishing technology-based standards and the second stage involves 
evaluating those standards that are based on MACT to determine whether 
additional standards are needed to address any remaining risk 
associated with HAP emissions. This second stage is commonly referred 
to as the ``residual risk review.'' In addition to the residual risk 
review, the CAA also requires the EPA to review standards set under CAA 
section 112 every 8 years and revise the standards as necessary taking 
into account any ``developments in practices, processes, or control 
technologies.'' This review is commonly referred to as the ``technology 
review'' and is the subject of this final action. The discussion that

[[Page 39313]]

follows identifies the most relevant statutory sections and briefly 
explains the contours of the methodology used to implement these 
statutory requirements.
    In the first stage of the CAA section 112 standard setting process, 
the EPA promulgates technology-based standards under CAA section 112(d) 
for categories of sources identified as emitting one or more of the HAP 
listed in CAA section 112(b). Sources of HAP emissions are either major 
sources or area sources, and CAA section 112 establishes different 
requirements for major source standards and area source standards. 
``Major sources'' are those that emit or have the potential to emit 10 
tons per year (tpy) or more of a single HAP or 25 tpy or more of any 
combination of HAP. All other sources are ``area sources.'' For major 
sources, CAA section 112(d)(2) provides that the technology-based 
NESHAP must reflect the maximum degree of emission reductions of HAP 
achievable (after considering cost, energy requirements, and nonair 
quality health and environmental impacts). These standards are commonly 
referred to as MACT standards. CAA section 112(d)(3) also establishes a 
minimum control level for MACT standards, known as the MACT ``floor.'' 
In certain instances, as provided in CAA section 112(h), the EPA may 
set work practice standards in lieu of numerical emission standards. 
The EPA must also consider control options that are more stringent than 
the floor. Standards more stringent than the floor are commonly 
referred to as beyond-the-floor standards. For categories of major 
sources and any area source categories subject to MACT standards, the 
second stage in standard-setting focuses on identifying and addressing 
any remaining (i.e., ``residual'') risk pursuant to CAA section 112(f) 
and concurrently conducting a technology review pursuant to CAA section 
112(d)(6). For categories of area sources subject to GACT standards, 
there is no requirement to address residual risk, but, similar to the 
major source categories, the technology review is required.
    A technology review is required for all standards established under 
CAA section 112(d) including GACT standards that apply to area 
sources.\4\ In conducting the technology review, the EPA is not 
required to recalculate the MACT floors that were established in 
earlier rulemakings. Natural Resources Defense Council (NRDC) v. EPA, 
529 F.3d 1077, 1084 (D.C. Cir. 2008). Association of Battery Recyclers, 
Inc. v. EPA, 716 F.3d 667 (D.C. Cir. 2013). The EPA may consider cost 
in deciding whether to revise the standards pursuant to CAA section 
112(d)(6). The EPA is required to address regulatory gaps, such as 
missing MACT standards for listed air toxics known to be emitted from 
the major source category, and any new MACT standards must be 
established under CAA sections 112(d)(2) and (3), or, in specific 
circumstances, CAA sections 112(d)(4) or (h). Louisiana Environmental 
Action Network (LEAN) v. EPA, 955 F.3d 1088 (D.C. Cir. 2020). For 
information on how EPA conducts a technology review, see 87 FR 35616 
(June 10, 2022).
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    \4\ For categories of area sources subject to GACT standards, 
CAA sections 112(d)(5) and (f)(5) provide that the EPA is not 
required to conduct a residual risk review under CAA section 
112(f)(2). However, the EPA is required to conduct periodic 
technology reviews under CAA section 112(d)(6).
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    Several additional CAA sections are relevant as they specifically 
address regulation of hazardous air pollutant emissions from area 
sources. Collectively, CAA sections 112(c)(3), (d)(5), and (k)(3) are 
the basis of the Area Source Program under the Urban Air Toxics 
Strategy, which provides the framework for regulation of area sources 
under CAA section 112.
    Section 112(k)(3)(B) of the CAA requires the EPA to identify at 
least 30 HAP that pose the greatest potential health threat in urban 
areas with a primary goal of achieving a 75 percent reduction in cancer 
incidence attributable to HAP emitted from stationary sources. As 
discussed in the Integrated Urban Air Toxics Strategy (64 FR 38706, 
38715; July 19, 1999), the EPA identified 30 HAP emitted from area 
sources that pose the greatest potential health threat in urban areas, 
and these HAP are commonly referred to as the ``30 urban HAP.''
    Section 112(c)(3), in turn, requires the EPA to list sufficient 
categories or subcategories of area sources to ensure that area sources 
representing 90 percent of the emissions of the 30 urban HAP are 
subject to regulation. The EPA implemented these requirements through 
the Integrated Urban Air Toxics Strategy by identifying and setting 
standards for categories of area sources including the Gasoline 
Distribution source category that is addressed in this action.
    CAA section 112(d)(5) provides that for area source categories, in 
lieu of setting MACT standards (which are generally required for major 
source categories), the EPA may elect to promulgate standards or 
requirements for area sources ``which provide for the use of generally 
available control technology or management practices [GACT] by such 
sources to reduce emissions of hazardous air pollutants.'' In 
developing such standards, the EPA evaluates the control technologies 
and management practices that reduce HAP emissions that are generally 
available for each area source category. Consistent with the 
legislative history, we can consider costs and economic impacts in 
determining what constitutes GACT.
    GACT standards were set for the Gasoline Distribution area source 
category in 2008. MACT standards were set for the Gasoline Distribution 
major source category in 1994 and the residual risk review and initial 
technology review for the major source category were completed in 2006. 
As noted above, this action finalizes the required CAA section 
112(d)(6) technology reviews for the standards for major and area 
sources in that source category.
2. NSPS
    The EPA's authority for the final NSPS rule is CAA section 111, 
which governs the establishment of standards of performance for 
stationary sources. Section 111(b)(1)(A) of the CAA requires the EPA 
Administrator to list categories of stationary sources that in the 
Administrator's judgment cause or contribute significantly to air 
pollution that may reasonably be anticipated to endanger public health 
or welfare. The EPA must then issue performance standards for new (and 
modified or reconstructed) sources in each source category pursuant to 
CAA section 111(b)(1)(B). These standards are referred to as new source 
performance standards, or NSPS. The EPA has the authority to define the 
scope of the source categories, determine the pollutants for which 
standards should be developed, set the emission level of the standards, 
and distinguish among classes, types, and sizes within categories in 
establishing the standards.
    CAA section 111(b)(1)(B) requires the EPA to ``at least every 8 
years review and, if appropriate, revise'' new source performance 
standards. However, the Administrator need not review any such standard 
if the ``Administrator determines that such review is not appropriate 
in light of readily available information on the efficacy'' of the 
standard. When conducting a review of an existing performance standard, 
the EPA has the discretion and authority to add emission limits for 
pollutants or emission sources not currently regulated for that source 
category.
    In setting or revising a performance standard, CAA section 
111(a)(1) provides that performance standards are to reflect ``the 
degree of emission limitation achievable through the application of the 
best system of emission reduction which (taking into

[[Page 39314]]

account the cost of achieving such reduction and any nonair quality 
health and environmental impact and energy requirements) the 
Administrator determines has been adequately demonstrated.'' The term 
``standard of performance'' in CAA section 111(a)(1) makes clear that 
the EPA is to determine both the BSER for the regulated sources in the 
source category and the degree of emission limitation achievable 
through application of the BSER. The EPA must then, pursuant to CAA 
section 111(b)(1)(B), promulgate standards of performance for new 
sources that reflect that level of stringency. CAA section 111(b)(5) 
generally precludes the EPA from prescribing a particular technological 
system that must be used to comply with a standard of performance. 
Rather, sources can select any measure or combination of measures that 
will achieve the standard. CAA section 111(h)(1) authorizes the 
Administrator to promulgate ``a design, equipment, work practice, or 
operational standard, or combination thereof'' if in his or her 
judgment, ``it is not feasible to prescribe or enforce a standard of 
performance.'' CAA section 111(h)(2) provides the circumstances under 
which prescribing or enforcing a standard of performance is ``not 
feasible,'' such as when the pollutant cannot be emitted through a 
conveyance designed to emit or capture the pollutant or when there is 
no practicable measurement methodology for the particular class of 
sources.
    Pursuant to the definition of ``new source'' in CAA section 
111(a)(2), standards of performance apply to facilities that begin 
construction, reconstruction, or modification after the date of 
publication of the proposed standards in the Federal Register. Under 
CAA section 111(a)(4), ``modification'' means any physical change in, 
or change in the method of operation of, a stationary source which 
increases the amount of any air pollutant emitted by such source or 
which results in the emission of any air pollutant not previously 
emitted. Changes to an existing facility that do not result in an 
increase in emissions are not considered modifications. Under the 
provisions in 40 CFR 60.15, ``reconstruction'' means the replacement of 
components of an existing facility such that: (1) The fixed capital 
cost of the new components exceeds 50 percent of the fixed capital cost 
that would be required to construct a comparable entirely new facility; 
and (2) it is technologically and economically feasible to meet the 
applicable standards.
    The NSPS were promulgated for Bulk Gasoline Terminals in 1983. As 
noted earlier in this preamble, this action finalizes the required NSPS 
review for that source category. For information on how the EPA 
conducts a NSPS review, see 87 FR 35616 (June 10, 2022).

B. What are the source categories regulated in this final action?

1. NESHAP Subpart R
    The EPA promulgated the major source Gasoline Distribution NESHAP 
on December 14, 1994 (59 FR 64303). The standards are codified at 40 
CFR part 63, subpart R. The major source gasoline distribution industry 
consists of bulk gasoline terminals and pipeline breakout stations. The 
source category covered by this MACT standard currently includes 210 
facilities.
    The primary sources of HAP emissions at bulk gasoline terminals are 
gasoline loading racks, gasoline cargo tanks, gasoline storage vessels, 
and equipment in gasoline service. The primary sources of HAP emissions 
at pipeline breakout stations are gasoline storage vessels and 
equipment in gasoline service. Emissions from loading racks at major 
source gasoline terminals under NESHAP subpart R are required to be 
controlled by a vapor collection and processing system to meet a TOC 
emission limit of 10 mg/L. Gasoline cargo tanks must be certified to be 
vapor tight using a graduated vapor tightness requirement of 1.0 to 2.5 
inches of water pressure drop over a 5-minute period, depending on the 
cargo tank compartment size for gasoline cargo tanks. Emissions from 
storage vessels with a design capacity greater than or equal to 75 
cubic meters must be controlled by equipment designed to suppress 
emissions (i.e., use an internal or external floating roof meeting 
certain requirements) or must capture and control emissions to a device 
achieving 95 percent reduction efficiency. Equipment leaks are subject 
to a leak detection and repair (LDAR) program using monthly inspections 
to identify leaks via audio, visual, or olfactory (AVO) methods and 
repair the leak identified.
2. NESHAP Subpart BBBBBB
    The EPA promulgated the area source Gasoline Distribution NESHAP on 
January 10, 2008 (73 FR 1916). The standards are codified at 40 CFR 
part 63, subpart BBBBBB. The area source gasoline distribution industry 
consists of bulk gasoline terminals, bulk gasoline plants, pipeline 
breakout stations, and pipeline pumping stations. The source category 
covered by this GACT standard currently includes approximately 9,000 
facilities.
    The primary sources of HAP emissions at bulk gasoline plants and 
bulk gasoline terminals are gasoline loading racks, gasoline cargo 
tanks, gasoline storage vessels, and equipment components in gasoline 
service. The primary sources of HAP emissions at pipeline breakout 
stations are gasoline storage vessels and equipment components in 
gasoline service; the HAP emissions at pipeline pumping stations are 
from equipment components in gasoline service. Emissions from loading 
racks at area source gasoline terminals with throughput of 250,000 
gallons per day or greater are required under NESHAP subpart BBBBBB to 
reduce emissions of TOC to less than or equal to 80 mg/L of gasoline. 
Small bulk gasoline terminals (terminals with a combined throughput 
between 20,000 and 250,000 gallons per day) and bulk gasoline plants 
(facilities with gasoline throughput of 20,000 gallons per day or less) 
are required to use submerged filling with a submerged fill pipe that 
is no more than 6 inches from the bottom of the cargo tank. Gasoline 
cargo tanks must be certified to be vapor tight using a maximum 
allowable pressure loss of 3 inches of water pressure drop over a 5-
minute period.
    At bulk gasoline terminals and pipeline breakout stations, 
emissions from storage vessels with a design capacity greater than or 
equal to 75 cubic meters and a gasoline throughput greater than 480 
gallons per day and all storage vessels with a design capacity greater 
than or equal to 151 cubic meters must be controlled by equipment 
designed to suppress emissions (i.e., use an internal or external 
floating roof meeting certain requirements) or must capture and control 
emissions to a device achieving 95 percent reduction efficiency. 
Storage vessels below these thresholds must have fixed roofs and must 
maintain all openings in a closed position at all times when not in 
use.
    Equipment leaks at all area source gasoline distribution facilities 
are subject to an LDAR program using monthly AVO methods.
3. NSPS
    The EPA first promulgated new source performance standards for Bulk 
Gasoline Terminals on August 18, 1983 (48 FR 37578). These standards of 
performance are codified in 40 CFR part 60, subpart XX, and are 
applicable to sources that commence construction, modification, or 
reconstruction after December 17, 1980, and on or before June 10, 2022. 
These standards of

[[Page 39315]]

performance regulate VOC emissions from bulk gasoline terminals.
    The affected facility to which the provisions of NSPS subpart XX 
apply is the total of all the loading racks at a bulk gasoline 
terminal. The primary sources of VOC emissions subject to NSPS subpart 
XX are gasoline loading racks, gasoline cargo tanks, and equipment 
associated with the loading rack and associated vapor collection and 
processing system. Emissions from gasoline storage vessels are subject 
to separate NSPS (see 40 CFR part 60, subparts K, Ka, and Kb). VOC 
emissions from loading racks at gasoline terminals subject to NSPS 
subpart XX must meet a TOC emission limit of 35 mg/L, except for 
modified affected facilities with an existing vapor processing system 
(as of December 17, 1980), which must meet a TOC emission limit of 80 
mg/L. Gasoline cargo tanks must be certified to be vapor tight using a 
maximum allowable pressure loss of 3 inches of water pressure drop over 
a 5-minute period. Leaks from equipment associated with the loading 
rack and associated vapor collection and processing system are subject 
to an LDAR program using monthly AVO methods.

C. What changes were proposed for the gasoline distribution NESHAP and 
for the bulk gasoline terminals NSPS in the June 10, 2022, proposal?

    On June 10, 2022, the EPA published proposed rules in the Federal 
Register for the Gasoline Distribution NESHAP, 40 CFR part 63, subparts 
R and BBBBBB, and Bulk Gasoline Terminal NSPS, 40 CFR part 60, subpart 
XXa, that took into consideration the TR and NSPS review and respective 
analyses.
1. NESHAP Subpart R
    In the proposed rule for the major source Gasoline Distribution 
NESHAP, 40 CFR part 63, subpart R, the EPA for new and existing sources 
proposed to:
    <bullet> Retain the 10 mg/L TOC emission limit for gasoline loading 
racks controlled by thermal oxidation systems.
    <bullet> Provide a 5,500 ppmv TOC emission limit for gasoline 
loading racks controlled by vapor recovery units (VRUs), which was 
determined to be equivalent to the 10 mg/L emission limit.
    <bullet> Reduce the allowable pressure drop for certifying gasoline 
cargo tanks as vapor tight to a graduated vapor tightness requirement 
of 0.5 to 1.25 inches of water, depending on the cargo tank compartment 
size for gasoline cargo tanks.
    <bullet> Include additional fitting requirements for storage 
vessels with external floating roofs.
    <bullet> Add a requirement for storage vessels with internal 
floating roofs to maintain the concentrations of vapors inside a 
storage vessel above the floating roof to less than 25 percent of the 
lower explosive limit (LEL).
    <bullet> Require semiannual monitoring using either optical gas 
imaging (OGI) or EPA Method 21 and repair leaks identified from these 
monitoring events or leaks identified by AVO methods during normal 
duties.
    <bullet> Revise certain requirements to clarify that the emission 
limits apply at all times.
    <bullet> Add electronic reporting requirements.
2. NESHAP Subpart BBBBBB
    In the proposed rule for the area source Gasoline Distribution 
NESHAP, 40 CFR part 63, subpart BBBBBB, the EPA proposed for new and 
existing sources to:
    <bullet> Reduce the TOC emission limit for loading racks at large 
bulk gasoline terminals from 80 mg/L to 35 mg/L.
    <bullet> Provide a 19,200 ppmv TOC emission limit for loading racks 
at large bulk gasoline terminals controlled by VRUs, which was 
determined to be equivalent to the 35 mg/L emission limit.
    <bullet> Reduce the allowable pressure drop for certifying gasoline 
cargo tanks as vapor tight to a graduated vapor tightness requirement 
of 0.5 to 1.25 inches of water, depending on the cargo tank compartment 
size for gasoline cargo tanks.
    <bullet> Include additional fitting requirements for storage 
vessels with external floating roofs.
    <bullet> Add a requirement for storage vessels with internal 
floating roofs to maintain the concentrations of vapors inside a 
storage vessel above the floating roof to less than 25 percent of the 
LEL.
    <bullet> Add requirements for bulk gasoline plants with a capacity 
over 4,000 gallons per day to use vapor balancing between gasoline 
cargo tanks and gasoline storage vessels.
    <bullet> Require pressure relief valves on fixed roof tanks to have 
opening pressures set to no less than 2.5 pounds per square inch gauge 
(psig).
    <bullet> Require annual monitoring using either OGI or EPA Method 
21 and repair leaks identified from these monitoring events or leaks 
identified by AVO methods during normal duties.
    <bullet> Revise certain requirements to clarify that the emission 
limits apply at all times.
    <bullet> Add electronic reporting requirements.
3. NSPS Subpart XXa
    In the proposed rule for Bulk Gasoline Terminal NSPS, 40 CFR part 
60, subpart XXa, the EPA proposed for new, modified, and reconstructed 
sources to:
    <bullet> Define the affected facility to include all equipment in 
gasoline service at the bulk gasoline terminal.
    <bullet> Limit VOC emissions as TOC from loading racks at new bulk 
gasoline terminals controlled with thermal oxidation systems to 1.0 mg/
L and limit TOC emissions from loading racks controlled with thermal 
oxidation systems at modified or reconstructed bulk gasoline terminals 
to 10 mg/L.
    <bullet> Provide 550 ppmv and 5,500 ppmv TOC emission limits for 
loading racks at bulk gasoline terminals controlled with VRUs, which 
were determined to be equivalent to the 1.0 mg/L and 10 mg/L proposed 
TOC emission limits, respectively.
    <bullet> Require certification of gasoline cargo tanks as vapor 
tight using a graduated vapor tightness requirement 0.5 to 1.25 inches 
of water, depending on the cargo tank compartment size for gasoline 
cargo tanks.
    <bullet> Require quarterly monitoring using either OGI or EPA 
Method 21 and repair leaks identified from these monitoring events or 
leaks identified by AVO methods during normal duties.
    <bullet> Clarify that the emission limits apply at all times.
    <bullet> Include electronic reporting requirements.

D. What outreach was conducted following the proposal?

    As part of these rulemakings and pursuant to multiple EOs 
addressing environmental justice (EJ), the EPA engaged and consulted 
with pertinent stakeholders and the public, including communities with 
environmental justice concerns. The EPA provided interactions such as 
conducting a public hearing, offering information on the websites for 
these rules, and informing the public of the proposed action by sending 
notifications with summaries of the action and information on how to 
comment to pertinent stakeholders. These opportunities gave the EPA a 
chance to hear directly from pertinent stakeholders and the public, 
especially communities potentially impacted by this final action. 
Summaries of the public hearing and comments received can be found in 
the docket for this action.

III. What is included in these final rules and what is the rationale 
for the final decisions and amendments?

    This action finalizes the EPA's determinations pursuant to the TR

[[Page 39316]]

provisions of CAA section 112 for the Gasoline Distribution major and 
area source categories and amends both Gasoline Distribution NESHAPs 
based on those determinations. This action also finalizes the removal 
of SSM exemptions in the NESHAP. The EPA is further finalizing 
determinations of its review of the Bulk Gasoline Terminals NSPS 
pursuant to CAA section 111(b)(1)(B). In addition, this action 
finalizes electronic reporting, monitoring and operating requirements 
for control devices, and other minor technical improvements. This 
action also reflects several changes to the June 10, 2022, proposal in 
consideration of comments received during the public comment period. 
For each issue, this section provides a description of what the EPA 
proposed and what the EPA is finalizing for the issue, the EPA's 
rationale for the final decisions and amendments, and a summary of key 
comments and responses. For all comments not discussed in this 
preamble, comment summaries and the EPA's responses can be found in the 
comment summary and response document available in the docket.

A. What are the final rule amendments based on the technology reviews 
for the gasoline distribution NESHAP and NSPS review for bulk gasoline 
terminals?

    The EPA determined that there are developments in practices, 
processes, and control technologies for loading operations, storage 
vessels, and equipment leaks that warrant revisions to NESHAP subpart R 
and NESHAP subpart BBBBBB.
    Therefore, to satisfy the requirements of CAA section 112(d)(6), 
the EPA is revising the NESHAP to include: a more stringent standard 
for gasoline loading racks at area sources, including requirements for 
vapor balancing for bulk gasoline plants with actual throughput of 
greater than 4,000 gallons per day; for both major and area sources, 
more stringent requirements for gasoline cargo tank vapor tightness; 
more stringent fitting control requirements for guidepoles on external 
floating roofs; the use of LEL monitoring to ensure the effectiveness 
of internal floating roofs; and instrument monitoring for equipment 
leaks. The final revisions are similar to those proposed. The most 
significant change from what was proposed is that we revised the 
throughput threshold requirement for which bulk gasoline plants must 
use vapor balancing to be determined by actual throughput rather than 
by maximum design capacity. Considering the analysis conducted to 
develop the 4,000 gallons per day threshold, provisions in NESHAP 
subpart BBBBBB, and comments received, the use of actual daily 
throughput and an annual averaging time is consistent with the analysis 
conducted and other provisions in NESHAP subpart BBBBBB. Upon 
consideration of public comments received, we also included an 
allowance to subtract methane from the TOC emission limit.
    Pursuant to the requirements of CAA section 111(b)(1)(B), the EPA 
determined that updates to the BSER are warranted and is revising the 
standards of performance for loading operations and equipment leaks. 
The EPA is finalizing the revisions to the NSPS in a new subpart, 40 
CFR part 60, subpart XXa, applicable to affected sources constructed, 
modified, or reconstructed after June 10, 2022. The NSPS subpart XXa 
includes: more stringent VOC standards (as TOC emission limits) for 
new, modified, or reconstructed gasoline loading racks; more stringent 
requirements for gasoline cargo tank vapor tightness; and instrument 
monitoring for equipment leaks. The final requirements in NSPS subpart 
XXa are similar to those proposed. The most significant change from 
what was proposed, after considering public comments received, is to 
define separate affected facilities: one specific to the loading rack 
and one specific to the equipment. Upon consideration of public 
comments received, we are also including an allowance to subtract 
methane from the TOC emission limit consistent with the most stringent 
emission limitations identified for new sources.
1. Standards for Loading Racks
    Because most of the standards proposed for loading racks were 
primarily in NSPS subpart XXa, we discuss our review of the loading 
racks NSPS provisions first, and then cover additional technology 
review issues specific to NESHAP subparts R and BBBBBB.
a. NSPS Subpart XXa
i. What did the EPA propose pursuant to CAA section 111 for loading 
racks at new, modified, or reconstructed bulk gasoline terminals?
    Based on the review of NSPS subpart XX requirements for loading 
racks at bulk gasoline terminals, we proposed to revise the TOC 
emission limit from loading racks at new bulk gasoline terminals 
controlled with thermal oxidation systems to 1.0 mg/L and to revise the 
TOC emission limit from loading racks at modified or reconstructed bulk 
gasoline terminals controlled with thermal oxidation systems to 10 mg/
L. For thermal oxidation systems, we proposed continuous compliance 
with a temperature operating limit established as the lowest 3-hour 
average temperature from a compliant performance test. We also proposed 
enhanced provisions for flares to ensure good combustion efficiency.
    For loading racks controlled with VRUs, we proposed corresponding 
emission limits of 550 ppmv and 5,500 ppmv TOC (as propane) for loading 
racks at new bulk gasoline terminals and for loading racks at modified 
or reconstructed bulk gasoline terminals, respectively. We determined 
that these concentration emission limits are, respectively, equivalent 
to the 1.0 mg/L and 10 mg/L proposed TOC emission limits for bulk 
gasoline terminals controlled with thermal oxidation systems. We 
proposed to express the concentration limit of 550 ppmv and 5,500 ppmv 
TOC (as propane) on a 3-hour rolling average because this provides an 
equivalent emission limit that is directly enforceable with the common 
monitoring systems used for VRUs. To prevent dilution, we proposed that 
only vacuum breaker valves can be used to introduce ambient air into 
the VRU control system.
    We also proposed revisions to the affected facility defined in NSPS 
subpart XXa at 40 CFR 60.500a to include additional equipment at the 
gasoline distribution facility beyond just that at the loading racks or 
vapor processing system.
ii. How did the NSPS review change for gasoline loading racks at new, 
modified, or reconstructed bulk gasoline terminals?
    We are finalizing the standards of performance for gasoline loading 
racks as proposed, except that we are including provisions to exclude 
the contribution of methane from the measured TOC emissions (as 
propane). As such, the final emission limits in NSPS subpart XXa are 
effectively 1.0 mg/L non-methane TOC for new sources and 10 mg/L non-
methane TOC for modified and reconstructed sources, but facilities may 
choose to comply using direct TOC measurements without correcting for 
methane content.
    We are also finalizing in the NSPS subpart XXa separate affected 
facility definitions for the loading racks and equipment. However, the 
loading rack affected facility definition in NSPS subpart XXa is 
similar to the provisions of NSPS subpart XX.

[[Page 39317]]

iii. What key comments did the EPA receive and what are the EPA's 
responses?
(A) Proposed Affected Facility
    Comment: Several commenters recommended that the EPA retain the 
NSPS subpart XX affected facility definition and not expand the 
affected facility under NSPS subpart XXa to include pumps and lines 
from storage vessels or the vapor collection and processing systems. 
One commenter stated that NSPS subpart XXa should be revised to clarify 
that a modification is triggered only by changes to the facility that 
result in an emissions increase associated with the loading rack 
itself, and not by changes to other equipment at the bulk gasoline 
terminal.
    Response: At proposal, we expanded the affected facility definition 
in NSPS subpart XXa to ensure that all gasoline service equipment at 
the bulk gasoline terminal is subject to the equipment leak monitoring 
requirements. However, we did not intend the result of adding a pump or 
valve in gasoline service to trigger additional loading rack control 
requirements. Therefore, in the final rule, we are instead defining two 
separate affected facilities: a ``gasoline loading rack affected 
facility'' and a ``collection of equipment at a bulk gasoline terminal 
affected facility.'' First, the gasoline loading rack affected facility 
is being defined as ``the total of all the loading racks at a bulk 
gasoline terminal that deliver liquid product into gasoline cargo tanks 
including the gasoline loading racks, the vapor collection systems, and 
the vapor processing system.'' This definition is similar to the 
affected facility definition in NSPS subpart XX. The loading rack 
emission limits apply specifically to the gasoline loading rack 
affected facility; therefore, new equipment in the tank farm area would 
not trigger NSPS applicability for the loading rack requirements. The 
collection of equipment at a bulk gasoline terminal affected facility 
is being defined as ``all equipment associated with the loading of 
gasoline at a bulk gasoline terminal including the lines and pumps 
transferring gasoline from storage vessels, the gasoline loading racks, 
the vapor collection systems, and the vapor processing system.'' This 
definition is consistent with our proposal and will ensure that all 
equipment associated with loading of gasoline at the bulk gasoline 
terminal is subject to the equipment leak provisions. The result of 
this finalized definition is that new equipment in the tank farm area 
would trigger NSPS subpart XXa applicability for the equipment leak 
requirements.
(B) Proposed Emission Limits
    Comment: Several commenters suggested that the 1 mg/L TOC emission 
limit for new facilities in NSPS subpart XXa is not cost-effective and 
has not been adequately demonstrated in practice. The commenters stated 
that the limit has not been demonstrated in practice because the 
permits impose a 1 mg/L non-methane hydrocarbon standard and the EPA 
did not propose to exclude methane from the TOC measurement. The 
commenters recommended that the EPA adopt a 10 mg/L TOC emission limit 
(or some lower limit but higher than 1 mg/L) that has been adequately 
demonstrated. According to one commenter, the only permits that they 
identified with a 1 mg/L limit were for sources in nonattainment areas 
subject to ``lowest achievable emission rate'' (LAER) requirements, 
which do not consider cost. The BSER, on the other hand, allows costs 
to be considered and the commenter stated that the 1 mg/L emission 
limit is not cost-effective. A commenter provided an example cost 
estimate, calculated cost effectiveness for each model plant, then 
averaged those to indicate that the ``average'' cost effectiveness was 
approximately $35,000 per ton VOC. Because the EPA noted that a cost of 
$8,300 per ton VOC is not cost-effective, the commenter concluded that 
the 1 mg/L emission limit is not cost-effective. One commenter 
suggested that the assumption of 8,760 hours of operation for the RACT/
BACT/LAER Clearinghouse facility used to establish the 1.0 mg/L 
emission limit for new sources is overly conservative and should be re-
evaluated and a lower new source emission limit should be established.
    Response: First, we recognize that NSPS subpart XX allows methane 
and ethane to be excluded from TOC as they are not VOC. However, based 
on the typical composition of gasoline, we did not expect that there 
would be appreciable quantities of methane or ethane in the gasoline 
vapors and thus concluded that the emission limit would be the same 
with or without the allowance to exclude methane and ethane. We also 
understand that the non-dispersive infrared (NDIR) monitor, which is a 
commonly used monitoring system for VRUs, can correct for methane 
concentration but not for ethane concentration. In reviewing the test 
and monitoring data for facilities meeting the 1.0 mg/L emission limit 
as well as the 10 mg/L emission limit, we concluded that it is 
possible, if not likely, that the reported TOC emissions already 
exclude methane, because the applicable limits allow the exclusion of 
methane from the TOC value and the instrument used to make the TOC 
measurements can simultaneously assess methane concentration and output 
non-methane TOC. These data are available in the docket. Because the 
source test summaries we have likely do not report the methane 
concentration measured, we cannot assess the impacts of including 
methane in the TOC. However, given the high removal efficiencies of 
VRUs achieving the 1.0 mg/L or 10 mg/L emission limit and the fact that 
methane is not well-controlled by carbon adsorption, it is possible 
that small quantities of methane in the gasoline vapors can 
significantly contribute to the TOC in the VRU exhaust. We also 
recognize that the 1.0 mg/L permit limit, upon which the new source 
emission limit in the proposed NSPS subpart XXa was established, is in 
terms of total non-methane hydrocarbon. While the contribution of 
ethane can be excluded from TOC based on provisions in NSPS subpart XX, 
the instruments commonly used to measure TOC cannot independently 
measure and correct for the contribution of ethane in TOC. Considering 
all of these factors, we are finalizing that the TOC emission limits 
may exclude methane content if measured according to EPA approved 
methods. We are not including provisions to exclude ethane content from 
measured TOC. We are also finalizing recordkeeping and reporting 
requirements that correspond to the revisions for excluding methane 
content from the TOC emission limits.
    With the allowance to exclude methane, we disagree that the 1.0 mg/
L TOC emission limit is not achievable. For example, the Buckeye Perth 
Amboy Terminal's U24 gasoline loading racks have had a 1 mg/L emission 
limit for nearly 10 years and we have two different source tests 
conducted several years apart that indicate that the system readily 
achieves a level of less than 1.0 mg/L non-methane TOC. In fact, while 
the facility is achieving the 1.0 mg/L emission limit, one of the tests 
indicated emissions of 0.6 mg/L non-methane TOC. However, considering 
process and ambient temperature variability, this source test suggests 
that a limit lower than 1.0 mg/L may not be achievable at all times. As 
such, we conclude that the 1.0 mg/L (non-methane) TOC limit is 
achievable and appropriate for new sources.
    With respect to our cost analysis, we maintain, as detailed in the 
June 10, 2022, proposal (87 FR 35622), that the 1.0 mg/L TOC emission 
limit for new sources is cost-effective. The commenter

[[Page 39318]]

indicated that a VRU used to meet 1 mg/L rather than 10 mg/L would be 
$300,000 more for all model plants. We disagree this is accurate for 
all model plants. The information we received from a control device 
manufacturer \5\ indicates that the smallest unit they make is 
essentially for model plant 3. Nonetheless, we added $100,000 to the 
cost of these smaller units when projecting the costs to meet 1 mg/L. 
Additionally, we note that smaller facilities will likely use a thermal 
oxidation system or flare instead of a VRU. For the largest facility 
(model plant 5), we estimated increased costs of $150,000. If we accept 
that a VRU for the largest model plant would cost an extra $300,000, 
the cost effectiveness from 10 mg/L to 1 mg/L is under $3,000 per ton 
of VOC, which we find cost-effective. We also note that the method used 
by the commenter to calculate the average cost effectiveness is not the 
way we calculate average cost effectiveness. We assess the total costs 
across all affected facilities and divide by the cumulative emission 
reductions across all affected facilities. Due to recent trends in 
inflation, interest rates, and gasoline prices, we re-evaluated our 
costs from 2019 dollars to 2021 dollars (the most recent year for which 
wage and other cost factors are available). While costs increased, 
product recovery credits also increased so the reanalysis did not alter 
our conclusions (see memorandum Updated New Source Performance 
Standards Review for Bulk Gasoline Terminals included in Docket ID No. 
EPA-HQ-OAR-2020-0371). Therefore, we maintain that 1.0 mg/L (non-
methane) TOC is the standard of performance that reflects the BSER for 
new sources.
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    \5\ See Docket ID No. EPA-HQ-OAR-2020-0371-0041.
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    Comment: One commenter noted that the EPA-proposed loading rack TOC 
emission limit of 10 mg/L for modified and reconstructed sources is 
less stringent than requirements for reconstructed sources that have 
been successfully implemented in some States, such as Massachusetts 
where loading rack emissions are limited to 2 mg/L in the permits for 
five reconstructed bulk gasoline terminals. According to the commenter, 
these standards should be viewed by the EPA as evidence of the cost 
effectiveness of those requirements. On the other hand, one commenter 
suggested that 35 mg/L is an appropriate standard for modified sources. 
The commenter noted that the EPA concluded that it was not cost-
effective to require area source facilities to upgrade to 10 mg/L for 
the NESHAP and the EPA failed to demonstrate why it would be cost-
effective for modified sources subject to the NSPS.
    Response: Based on our cost analysis as provided in the proposal 
(June 10, 2022; 87 FR 35622), we determined that it was not cost-
effective to require existing sources that are modified or 
reconstructed to meet a 1 mg/L TOC emission limit. While we did not 
specifically evaluate a 2 mg/L limit, we expect that the upgrades 
needed to meet a 2 mg/L limit would be essentially the same as those 
needed to meet a 1 mg/L limit and would likewise not be cost-effective. 
With respect to differences in conclusion for modified and 
reconstructed sources in NSPS subpart XXa as compared to the revised 
standards for NESHAP subpart BBBBBB, the assessment that a 35 mg/L 
limit was the appropriate level for NESHAP subpart BBBBBB was based on 
the cost effectiveness of the HAP emission reductions, which were 
estimated to be only 4 percent of the VOC emission reductions. However, 
for the NSPS subpart XXa analysis, we found, when considering the VOC 
emission reductions, that it was cost-effective for modified and 
reconstructed sources to require control system upgrades to meet a 10 
mg/L TOC limit. We therefore maintain that, when considering VOC 
emission reductions, a 10 mg/L TOC limit is cost-effective and is the 
standard of performance that reflects the BSER for modified and 
reconstructed sources.
(C) Proposed Monitoring Requirements
    Comment: Several commenters stated that the flare monitoring 
provisions to meet the requirements in the Refinery NESHAP at 40 CFR 
63.670 and that were proposed as an alternative for NESHAP subpart 
BBBBBB are also appropriate for meeting the 10 mg/L TOC limit for 
modified and reconstructed sources and therefore should be allowed as a 
compliance alternative to continuous temperature monitoring for thermal 
oxidation systems in NSPS subpart XXa and NESHAP subpart R subject to 
the 10 mg/L emission limit. One commenter recommended that the 
following revisions be made for ``flare provisions'' if added for 
thermal oxidation systems meeting the 10 mg/L limit:
    <bullet> Eliminate the flare tip velocity limit or allow its 
determination using an engineering assessment.
    <bullet> Eliminate the net heating value dilution 
(NHV<INF>dil</INF>) operating parameter requirement because of 
differences in refinery flares and gasoline distribution thermal 
oxidation systems.
    On the other hand, one commenter stated that the proposed flare 
monitoring requirements were inadequate to demonstrate continuous 
compliance. According to the commenter, net heating values of the gas 
streams at gasoline distribution facilities exhibit significant 
variability and 2 weeks of sampling cannot capture this variability. 
Furthermore, the commenter noted, the proposed sampling allowance 
incentivizes gasoline distribution facilities to sample when net 
heating values are higher than normal to minimize (or eliminate) the 
need to add supplemental fuel. Similarly, the commenter noted, the 
proposed single sample collected when loading a single gasoline cargo 
tank was not sufficient to determine compliance with the 
NHV<INF>dil</INF> parameter. According to the commenter, continuous 
composition or net heating value monitoring must be required for flares 
(or grab sampling every 8 hours).
    Response: We agree with the commenters who suggest that the flare 
monitoring provisions are appropriate and can be allowed for thermal 
oxidation systems subject to the 10 mg/L TOC emission limit, because 
the thermal oxidation systems used in the gasoline distribution 
industry are largely enclosed combustors. The flare monitoring 
provisions are commensurate with meeting a 10 mg/L emission limit and 
that is why we proposed that flares could be used to meet the 10 mg/L 
emission limit for modified and reconstructed sources, but not for new 
sources subject to the 1 mg/L emission limit.
    We also agree that, because gasoline loading must be conducted at 
low pressures (less than 18 inches of water pressure), it is very 
unlikely that the flare tip velocity limits would ever be exceeded and 
that a design evaluation could be conducted to assess the maximum 
loading rate (vapor displacement rate) to determine if, based on the 
flare tip diameter (and number of flare tips, if staged flare tip 
design is used), the flare tip velocity would always be below 60 feet 
per second. If so, net heating value measurements and continuous flow 
monitoring would not be needed to demonstrate compliance with the flare 
tip velocity limit. Therefore, we are including in the final NSPS 
subpart XXa at 40 CFR 60.502a(c)(3)(ix) provisions to comply with the 
flare tip velocity limit using the provisions as described earlier. We 
are also specifying that records of these one-time flare tip velocity 
assessment must be maintained for as long as the owner or operator is 
using this compliance provision.

[[Page 39319]]

    We disagree that these enclosed combustors cannot be over-assisted 
and maintain that the proposed NHV<INF>dil</INF> operating limit is 
needed. The air-assist operating parameter was developed based on a 
flare manufacturer testing facility using propane or propylene as the 
fuel with flare tips ranging from 1.5 inches to 24 inches in diameter. 
As such, we consider these test data to be widely applicable to a 
variety of industrial flares. We understand that the burner tips in 
most thermal oxidation systems are staged with air-assist at each tip. 
This would be similar to the 1.5-inch flare tip included in the study 
data. The wind speeds during the test of this small flare were low, 
typically under 5 miles per hour (mph), and the performance of the 
flare was not a function of wind speed. The commenter provided no data 
or reasonable argument to support the idea that enclosed combustors 
cannot be over-assisted. Therefore, we are retaining the requirements 
to meet the NHV<INF>dil</INF> operating limit.
    While we agree that the flare monitoring requirements in the 
Refinery NESHAP at 40 CFR 63.670 are reasonable for sources subject to 
the 10 mg/L TOC emission limit, we also agree that the operating limits 
included in 40 CFR 63.670 must be met at all times when liquid product 
is loaded into gasoline cargo tanks. Based on the comments received, we 
considered the impacts of different relative loading rates of gasoline 
and diesel fuel (or other non-gasoline products) and agree that the net 
heating value of vapors directed to the flare or thermal oxidation 
system can vary significantly based on the types and the relative 
volumes of products loaded. We expect that the provisions in 40 CFR 
63.670(j)(6) are reasonable for flare gas streams that ``. . . have 
consistent composition (or a fixed minimum net heating value) . . .'' 
and we expect that gasoline loading operations (loading only gasoline 
products) would meet this criterion regardless of the grade of gasoline 
loaded (regular, premium, or non-ethanol) as the net heating value of 
the vapors would always be well above 270 Btu/scf. However, if other 
liquid products are loaded into non-gasoline cargo tanks and the 
displaced vapors from these loading operations are also sent to the 
same flare, then the vapors discharged to the flare would not have a 
consistent composition or a fixed minimum net heating value. Therefore, 
we are clarifying in 40 CFR 60.502a(c)(3)(vii) that, for the purposes 
of NSPS subpart XXa, the application for an exemption from monitoring 
required under 40 CFR 63.670(j)(6) must include a minimum ratio of 
gasoline loaded to total liquid product loaded and, if perimeter air-
assisted, a minimum gasoline loading rate. We consider this to be part 
of the explanation of conditions that ensure that the flare gas net 
heating value is consistent and of conditions expected to produce the 
flare gas with lowest net heating value as required in 40 CFR 
63.670(j)(6)(i)(C). We are also clarifying that, as required in 40 CFR 
63.670(j)(6)(i)(D), samples must be collected at the conditions 
expected to produce the flare gas with lowest net heating value as 
identified in 40 CFR 63.670(j)(6)(i)(C), which includes the applicable 
minimum gasoline loading rates identified in the application.
    Furthermore, we are specifying that the affected source must 
operate at or above the minimum values specified in its application at 
all times when liquid product is loaded into cargo tanks for which 
vapors collected are sent to the flare or, if applicable, to a thermal 
oxidation system. We consider that the provisions of 40 CFR 
63.670(j)(6) are reasonable and can be used to demonstrate that the net 
heating value of the vapors collected and sent to the flare (or thermal 
oxidation system) are sufficient to comply with the flare net heating 
value operating limits. However, given the variability in net heating 
values expected with the loading of different liquid products, we 
determined that clarifying how the provisions of 40 CFR 63.670(j)(6) 
should be applied for the gasoline distribution industry was 
appropriate. We also concluded that it was critical to set these 
minimum gasoline loading rates as operating limits to ensure continuous 
compliance with the conditions tested as part of the application. For 
flares (or thermal oxidation systems) that are unassisted or perimeter 
air-assisted, the vent gas net heating value is the same as the 
combustion zone net heating value (NHV<INF>cz</INF>). If the testing 
conducted under 40 CFR 63.670(j)(6) as specified in 40 CFR 
60.502a(c)(3)(vii) shows that the vent gas net heating value meets or 
exceeds the NHV<INF>cz</INF> operating limit, compliance with the 
minimum ratio of the volume of gasoline loaded to total liquid products 
loaded can be used directly to demonstrate compliance with the 
NHV<INF>cz</INF> operating limit. Similarly, for perimeter air-assisted 
flares (or thermal oxidation systems), if the testing conducted under 
40 CFR 63.670(j)(6) as specified in 40 CFR 60.502a(c)(3)(vii) shows 
that the device meets or exceeds the NHV<INF>dil</INF> operating limit 
at the highest fixed or highest air-assist rate used, then compliance 
with the minimum gasoline loading rate can be used directly to 
demonstrate compliance with the NHV<INF>dil</INF> operating limit.
    We considered using the 15-minute block periods as specified in the 
cross-referenced requirements in 40 CFR 63.670(e) and (f) for these 
loading ratio or loading rate operating limits. However, we expected 
there may be issues at the end of a loading event if gasoline loading 
ended 1-minute into the next 15-minute block if the owner or operator 
was required to meet a minimum gasoline loading rate for that 15-minute 
block. Considering comments received on the 3-hour rolling average, 
which suggested using 36 5-minute periods, we are finalizing provisions 
at 40 CFR 60.502a(c)(3)(vii)(E) that the loading rate operating limit 
will be monitored on 5-minute block periods and calculated on a rolling 
15-minute period across three contiguous 5-minute block periods. We 
used the term ``contiguous'' here to highlight that these periods are 
connected without a break, unlike the ``consecutive'' periods used in 
the definition of 3-hour rolling average. We also note that the 
operating limits in 40 CFR 63.670(e) and (f), as modified in 40 CFR 
60.502a(c)(3)(i), apply when ``vapors displaced from gasoline cargo 
tanks during product loading is routed to the flare for at least 15-
minutes.'' For the liquid product loading operating limits used as an 
alternative to meet 40 CFR 63.670(e) and (f), we are requiring these 
limits be calculated on a rolling 15-minute period basis considering 
only those periods when liquid product is loaded into gasoline cargo 
tanks for any portion of three contiguous 5-minute block periods. The 
phrase ``any portion of three contiguous 5-minute block periods'' 
reflects, in practice, how one would determine when ``vapors displaced 
from gasoline cargo tanks during product loading is routed to the flare 
for at least 15-minutes.'' If there is a 5-minute block when no liquid 
product was loaded into gasoline cargo tanks, then the previous rolling 
15-minute period would end and the next rolling 15-minute period would 
not be calculated until there are three contiguous 5-minute block 
periods in which liquid product was loaded into gasoline cargo tanks 
for at least some portion of each of the three contiguous 5-minute 
block periods. With these clarifications and added operating limits, we 
conclude that the provisions allowing a one-time net heating value 
determination according to the provisions of 40 CFR 63.670(j)(6) are 
sufficient for demonstrating continuous

[[Page 39320]]

compliance with the net heating value operating limits.
    With respect to the comment received opposing the proposed use of a 
single sample while loading only gasoline to assess the 
NHV<INF>dil</INF> operating limit, we note that this operating 
parameter is an issue primarily when the waste gas flow rate is low. 
Therefore, we sought to assess whether auxiliary fuel was needed to 
ensure combustion at these low flow rates, which would occur when 
loading a single gasoline cargo tank. However, upon further review, we 
expect the NHV<INF>dil</INF> operating limit to be most difficult to 
meet when the gasoline loading rate is at its minimum and the net 
heating value is low (as when the ratio of the volume of gasoline 
loaded to total liquid product loaded is at its minimum). Therefore, we 
stipulated that facility owners or operators would have to establish 
these minimums in their application and test the net heating value of 
the vent gas under those circumstances. With these conditions clearly 
delineated in the final provisions at 40 CFR 60.502a(c)(3)(vii), no 
additional sampling requirements are needed in the proposed 
requirements at 40 CFR 60.502a(c)(3)(ix), which are now included within 
40 CFR 60.502a(c)(3)(viii) of the final rule. Consistent with the flare 
provisions at 40 CFR 63.670(j)(6)(i)(F), a single value for the vent 
gas net heating value (either the lowest single value or the 95th 
percent confidence value) must be used for all vent gas flow rates. 
Therefore, consistent with the provisions at 40 CFR 63.670(j)(6)(i)(F), 
flare (or thermal oxidation system) owners or operators must use the 
net heating value as determined based on the sampling conducted 
consistent with their application under 40 CFR 63.670(j)(6). With the 
elimination of the separate sampling protocol, we are combining the 
revisions proposed at 40 CFR 60.502a(c)(3)(ix) with those proposed at 
40 CFR 60.502a(c)(3)(viii). Thus, 40 CFR 60.502a(c)(3)(viii) now 
contains a single assessment of the quantity of natural gas needed in 
order to demonstrate continuous compliance with the NHV<INF>cz</INF> 
operating limit and, if applicable, with the NHV<INF>dil</INF> 
operating limit. Because the net heating value parameter used under 40 
CFR 60.502a(c)(3)(viii) is now the one determined under 40 CFR 
60.502a(c)(3)(vii), facilities electing this option would also have to 
monitor and comply with the minimum ratio of gasoline to total liquid 
products loaded and, if applicable, the minimum gasoline loading rate. 
We also note that we expect far fewer facilities will use the minimum 
supplemental gas addition rate option in 40 CFR 60.502a(c)(3)(viii) 
because this option would only be needed if the owner or operator 
cannot demonstrate compliance with the flare operating limits based 
solely on the vent gas net heating value and the minimum ratio of 
gasoline to total liquid products loaded and, if applicable, the 
minimum gasoline loading rate as determined under 40 CFR 
60.502a(c)(3)(vii).
    Because the provisions in the final rule more clearly account for 
the variability of the net heating value of the vapors sent to the 
flare based on the different liquid products loaded, we consider the 
final provisions to be more robust than those initially proposed and we 
consider them reasonable and appropriate for demonstrating continuous 
compliance with the flare provisions or for a thermal oxidation system 
subject to a 10 mg/L TOC emission limit. Therefore, we are finalizing 
the flare monitoring alternative for thermal oxidation systems for 
modified or reconstructed gasoline loading rack affected facilities 
under NSPS subpart XXa. Because NESHAP subpart R also has a 10 mg/L 
emission limit, we determined that the flare monitoring alternative in 
NSPS subpart XXa can be used for thermal oxidation systems used to 
control emissions from loading racks at bulk gasoline terminals subject 
to NESHAP subpart R. We are also retaining the proposed provisions that 
thermal oxidation systems used to control emissions from loading racks 
at bulk gasoline terminals subject to NESHAP subpart BBBBBB can use 
these flare monitoring alternatives in NSPS subpart XXa.
    Comment: Several commenters objected to the proposed definition of 
a ``3-hour rolling average.'' According to the commenters, regulated 
parties cannot comply with the proposed definition because they cannot 
determine the point in time when ``all emissions from the loading event 
have cleared the control device'' particularly for VRUs. According to 
the commenter, vapors from loading may be processed and recovered in a 
VRU well after active loading is completed. The commenters recommended 
that this phrase be deleted from the proposed definition of ``3-hour 
rolling average.'' One commenter noted that the proposed definition of 
``3-hour rolling average'' differs significantly from industry practice 
and, thus, would require a reprogramming of the programmable logic 
controllers for virtually all existing units, as well as likely 
revision of thousands of permits. One commenter noted that the clause, 
``periods when gasoline loading is not being conducted are not 
considered valid data,'' is inconsistent with the definition of 
gasoline cargo tank, where diesel fuel loading into a cargo tank that 
previously had gasoline should be counted, and so the entire sentence 
should be deleted. The commenter also suggested that the 3-hour average 
should be clarified to consist of thirty-six 5-minute periods of valid 
data. One commenter noted that data from periods when gasoline loading 
is not being conducted may be necessary to demonstrate compliance with 
permit or other requirements. Commenters also recommended that, because 
the performance test is a 6-hour test, the EPA should use a 6-hour 
rolling average for the proposed concentration limits for VRUs (rather 
than a 3-hour rolling average). According to commenters, the 3-hour 
averaging time makes the standard more stringent, and the longer 6-hour 
averaging period for the emission limit (or operating parameter) would 
be more representative of the conditions seen throughout the day. 
According to some commenters, the 3-hour average combined with the 
numerical limit established for VRUs will either require upgrades of 
control systems or result in either slowdowns or shutdowns of gasoline 
loading during the heat of the day, creating artificial fuel 
availability constraints.
    Response: First, we agree with commenters that it is difficult to 
know when all vapors have cleared the control device system, 
particularly when a vapor recovery system is used. When a vapor 
recovery system is used, there may be emissions during carbon bed 
regeneration even when there is no liquid product being loaded into 
gasoline cargo tanks. For thermal oxidation systems, on the other hand, 
the vapors clear the control device in a matter of a minute or two. 
Therefore, rather than using this general phrase within the definition 
of ``3-hour rolling average,'' we are specifying within the control 
device-specific requirements in 40 CFR 60.502a what constitutes valid 
data that must be included in the 3-hour rolling average. For vapor 
recovery systems, the 3-hour rolling average concentration emission 
limit applies during all periods when the vapor recovery system is 
operating, which may include times when no liquid product is being 
loaded but the system is still online and capable of processing 
gasoline vapors. We also note that the vapor recovery system must be 
operating, at a minimum, whenever liquid product is loaded into 
gasoline cargo tanks. For thermal oxidation

[[Page 39321]]

systems, where the gasoline vapors quickly pass through the control 
system, the 3-hour rolling average applies specifically when liquid 
product is loaded into gasoline cargo tanks.
    We agree with the commenter who noted that the definition of 
gasoline cargo tank includes tank trucks or railcars into which 
gasoline is being loaded or that contained gasoline on the immediately 
previous load. There are several places in the proposed rules where we 
used ``loading gasoline'' when the correct term is ``loading liquid 
product into a gasoline cargo tank.'' We are revising this terminology 
throughout each of the gasoline distribution rules. We also are 
clarifying (in the description of the monitored parameter, i.e., 
combustion zone temperature) how the ``previous load'' impacts the 
valid data for the operating limit. If an owner or operator has 
information on previous cargo tank contents, then they may exclude from 
the 3-hour rolling average those periods when there is liquid product 
being loaded but there are no gasoline cargo tanks being loaded. If an 
owner or operator does not have information on previous cargo tank 
contents, then they must assume that liquid product loading is loaded 
into a gasoline cargo tank and must meet the operating limit during 
periods of liquid product loading, because the cargo tank could have 
contained gasoline on the immediately previous load. All owners or 
operators of thermal oxidizer systems must exclude from the 3-hour 
rolling average those periods when there is no liquid product being 
loaded. Because we acknowledge that liquid product loading can be very 
intermittent, we agree that the operating limit should be evaluated on 
5-minute periods. If any liquid product is loaded into a gasoline cargo 
tank during a 5-minute period, that 5-minute period must be included in 
the 3-hour rolling average.
    With respect to the stringency of the 3-hour rolling average 
combined with the concentration limit established for VRUs, we first 
note that we used direct calculation of vapors displaced during loading 
to determine the concentration limit equivalent to the 1.0 and 10 mg/L 
TOC emission limits. We also note that the current rules do not specify 
an averaging time for the operating parameters. As discussed in the 
preamble of the June 10, 2022, proposal (87 FR 35618), part of our 
motivation in setting numerical concentration standards and 
establishing specific timeframes for operating limits is to make 
requirements for all gasoline distribution facilities consistent. While 
we recognize that the performance test is 6 hours in duration for 
thermal oxidation systems, there is no longer a performance test for 
VRUs. Owners or operators of VRUs must conduct performance evaluations 
of their TOC continuous emission monitoring system (CEMS). The 
performance evaluation consists of a minimum of nine test runs, with 
each test run being a sampling traverse of a minimum of 21 minutes in 
duration. Thus, the performance evaluation is a minimum of 189 minutes 
in duration, which is approximately 3 hours. We selected a 3-hour 
average to be consistent with the duration of the performance 
evaluation. We also proposed that the temperature operating limit for 
thermal oxidation systems will be determined on a 3-hour rolling 
average basis and provided specific requirements on how that 3-hour 
rolling average temperature operating limit must be developed.
    Upon consideration of the comments received, we are maintaining the 
use of a 3-hour rolling average for CEMS and operating parameters used 
to demonstrate continuous compliance. However, we are revising and 
clarifying the definition of ``3-hour rolling average'' to more clearly 
delineate data that must be included in the 3-hour rolling average 
based on the type of control system used and more appropriately to use 
the phrase ``gasoline cargo tank'' and account for periods when a non-
gasoline product is loaded into a cargo tank that contained gasoline 
during its previous load.
(D) Proposed VRU Operation To Minimize Air Intrusion
    Comment: Several commenters expressed concern over the EPA's 
proposed requirement that only vacuum breaker valves can be used to 
introduce ambient air into the VRU control system in order to prevent 
dilution of the emissions measurement. According to the commenters, the 
proposed rule could, if misinterpreted, impact the design and operation 
of carbon-based vapor recovery units. The use of pressure swing 
adsorption is the underlying basis for most, if not all, VRUs in 
operation in the U.S. According to the commenters, the use of purge air 
at the completion of a regeneration cycle (while the system is under 
vacuum) is a critical step in the operation of a VRU and is integral to 
its effectiveness.
    Response: We understand the concern commenters have with the 
proposed requirements that only vacuum breaker valves can be used to 
introduce ambient air into the VRU. Both operators and control device 
manufacturers have indicated that the introduction of some purge air 
(or nitrogen) while the unit is under vacuum is critical for effective 
VRU performance. Upon review of the information provided by commenters, 
we are revising 40 CFR 60.502a(b)(2)(iii) and (c)(2)(iii) to require 
the facility to ``[o]perate the vapor recovery system to minimize air 
or nitrogen intrusion except as needed for the system to operate as 
designed for the purpose of removing VOC from the adsorption media or 
to break vacuum in the system and bring the system back to atmospheric 
pressure. Consistent with Sec.  60.12, the use of gaseous diluents to 
achieve compliance with a standard which is based on the concentration 
of a pollutant in the gases discharged to the atmosphere is 
prohibited.''
iv. What is the rationale for the EPA's final approach for the NSPS 
review?
    As described in the preamble to the June 2022 proposal (87 FR 
35622; June 10, 2022), we determined that the BSER was VRU with 
submerged loading for new bulk gasoline terminals and the TOC emission 
limitation that reflects the application of the BSER is 1.0 mg/L. For 
systems with a VRU, this is a concentration of 550 ppmv TOC (as 
propane), which we determined was equivalent to an emission limit of 
1.0 mg/L. We also determined in the June 2022 proposal that the BSER 
for modified or reconstructed bulk gasoline terminals was VRU with 
submerged loading and the TOC emission limitation that reflects the 
application of the BSER is 10 mg/L. For systems using a VRU, this is a 
concentration of 5,500 ppmv TOC (as propane), which we determined was 
equivalent to an emission limit of 10 mg/L. Consistent with our 
proposed BSER analysis, we are finalizing our determination that the 
BSER is VRU and the loading rack TOC emission limits are 1.0 mg/L, or 
550 ppmv TOC (as propane) for facilities controlled with vapor recovery 
systems, for new bulk gasoline terminals and 10 mg/L, or 5,500 ppmv TOC 
(as propane) for facilities controlled with vapor recovery systems, for 
modified or reconstructed bulk gasoline terminals, as proposed except 
that we are allowing the exclusion of methane from the measured TOC for 
reasons discussed in section III.A.1.a.iii of this preamble. With the 
exclusion of methane, we are finalizing additional test methods 
applicable for non-methane organic carbon and additional reporting 
requirements to indicate whether the measurement method used in the 
performance test or CEMS corrects for methane concentration. We are 
also finalizing recordkeeping and reporting requirements that 
correspond to the

[[Page 39322]]

revisions for excluding methane content from the TOC emission limits.
    For reasons discussed in section III.A.1.a.iii of this preamble, we 
are finalizing two separate affected facilities definitions for NSPS 
subpart XXa: ``gasoline loading rack affected facility'' and 
``collection of equipment at a bulk gasoline terminal affected 
facility.'' The ``gasoline loading rack affected facility'' definition 
being finalized is similar to the affected facility definition in NSPS 
subpart XX. We are providing separate affected facilities definitions 
to expand the equipment leak provisions to all equipment in gasoline 
service at the bulk gasoline terminal, so that the equipment changes 
that are remote from the loading racks and associated vapor processing 
system do not trigger a modification to the loading rack affected 
facility.
    Because flares can be used to comply with the 10 mg/L TOC emission 
limit and because many thermal oxidation systems used in the gasoline 
distribution industry are enclosed combustors, we find that the flare 
monitoring alternatives are appropriate for thermal oxidation systems 
required to meet the 10 mg/L emission limit. We are clarifying in the 
final rule at 40 CFR 60.502a(c)(3)(vii) the requirements for using one-
time assessment of net heating value for vapors with consistent 
composition or a minimum net heating value as provided in 40 CFR 
63.670(j)(6) when vapors from loading of different liquid products are 
processed by the flare or thermal oxidation system. We are requiring 
facilities using this one-time assessment to monitor gasoline and total 
liquid product loading rates and maintain the ratio of gasoline to 
total liquid product loaded above the levels in their application under 
40 CFR 63.670(j)(6). For perimeter air-assisted flares or thermal 
oxidation systems, gasoline loading rates must also be maintained as 
levels at or above the minimum gasoline loading rates specified in 
their application under 40 CFR 63.670(j)(6). We are also finalizing 
recordkeeping and reporting requirements that correspond to the 
requirements to maintain a minimum ratio of gasoline to total liquid 
product loaded and, if applicable, a minimum gasoline loading rate.
    For reasons described in section III.A.1.a.iii.C of this preamble, 
we are finalizing a provision at 40 CFR 60.502a(c)(3)(ix) for 
conducting a one-time engineering assessment as a means to demonstrate 
compliance with the flare tip velocity operating limits. We are also 
finalizing recordkeeping requirements related to this one-time 
assessment when this compliance method is used.
    We are finalizing revised provisions at 40 CFR 60.502a(b)(2)(iii) 
and (c)(2)(iii) to allow some purge air or nitrogen to be introduced 
while the system is under vacuum and being regenerated as needed to 
effectively remove VOC from the adsorption media, based on evaluation 
of comments received. We based the final NSPS limits largely on the 
emission limits achieved by VRUs in practice. We found the description 
of the process, especially from the carbon adsorption system vendors, 
compelling, and we did not intend for our proposal to alter the 
regeneration methods used for the control systems upon which the BSER 
was established. Our final provision regarding the vacuum purge retains 
the limitation that, consistent with 40 CFR 60.12, the use of gaseous 
diluents to achieve compliance with a standard which is based on the 
concentration of a pollutant in the gases discharged to the atmosphere 
is prohibited.
    After a review of all the comments, we are adding details of the 
time periods that must be included or excluded from the 3-hour rolling 
average as part of the requirements of the monitoring operating 
parameters. This allows us to specify the time periods applicable to 
different control devices rather than using the general phrase ``all 
emissions from the loading event have cleared the control device.'' For 
thermal oxidation systems, we are clarifying that the operating limits 
apply at all times when liquid product is loaded into gasoline cargo 
tanks. We are also finalizing requirements that, if the immediately 
previous load of a cargo tank is not known, then the cargo tank must be 
assumed to be a gasoline cargo tank. We are also finalizing 
requirements that periods when there is no liquid product loading must 
be excluded from the 3-hour rolling average. For vapor recovery 
systems, we are clarifying that the operating limits apply at all times 
that the vapor system is operating, because emissions can come from the 
regeneration of a carbon bed even though there is no liquid product 
loading. We are also adding recordkeeping and reporting requirements 
related to periods when gasoline cargo tanks are being loaded as well 
as an indication as to whether cargo tanks are assumed to be gasoline 
cargo tanks because the previous load of the cargo tank being loaded is 
unknown.
    With these specific time frames moved to the description of the 
monitoring requirements for the monitored parameters, we are finalizing 
the definition at 40 CFR 60.501a of ``3-hour rolling average'' as 
follows:
    3-hour rolling average means the arithmetic mean of the previous 
thirty-six 5-minute periods of valid operating data collected, as 
specified, for the monitored parameter. Valid data excludes data 
collected during periods when the monitoring system is out of control, 
while conducting repairs associated with periods when the monitoring 
system is out of control, or while conducting required monitoring 
system quality assurance or quality control activities. The thirty-six 
5-minute periods should be consecutive, but not necessarily continuous 
if operations or the collection of valid data were intermittent.
b. NESHAP Subpart R
i. What did the EPA propose pursuant to CAA section 112(d)(6) for the 
major source gasoline distribution source category?
    Based on our technology review for loading racks at major sources, 
we proposed to retain the 10 mg/L TOC emission limit currently required 
in NESHAP subpart R. However, we proposed that the 10 mg/L TOC emission 
limit would apply to loading racks controlled by thermal oxidation 
systems or flares. For thermal oxidation systems, we proposed 
continuous compliance with a temperature operating limit established as 
the lowest 3-hour average temperature from a compliant performance 
test. For flares, we proposed enhanced provisions to ensure good 
combustion efficiency. For loading racks controlled by VRUs, we 
proposed to express this emission limit in terms of a concentration 
limit of 5,500 ppmv TOC (as propane) on a 3-hour rolling average 
because this provides an equivalent emission limit that is directly 
enforceable with the common monitoring systems used for VRUs. To 
prevent dilution, we proposed that only vacuum breaker valves can be 
used to introduce ambient air into the VRU control system.
ii. How did the technology review change for gasoline loading racks at 
major source gasoline distribution facilities?
    The are no significant changes in the technology review conclusions 
for loading racks at major source gasoline distribution facilities.
iii. What key comments did the EPA receive and what are the EPA's 
responses?
    Several commenters supported the conclusion to maintain the 10 mg/L

[[Page 39323]]

TOC emission limit for major source gasoline distribution facilities.
iv. What is the rationale for the EPA's final approach for the 
technology review?
    We are finalizing the loading rack emission limits as proposed. 
Because many of the specific monitoring requirements cross-reference 
provisions in NSPS subpart XXa, revisions related to allowing the 
exclusion of methane from measured TOC, allowance for thermal oxidation 
systems to use the flare monitoring provisions, use of vacuum purge gas 
for VRUs, and revisions to the definition of 3-hour rolling average 
also impact the final requirements and associated recordkeeping and 
reporting requirements for gasoline loading operations at major source 
facilities. Our rationale for these revisions is summarized in section 
III.A.1.a.iv of this preamble.
    At proposal, we specifically excluded reference to 40 CFR 
60.504a(d) at proposed 40 CFR 63.428(d) because we did not intend to 
require facilities subject to NESHAP subpart R to install pressure CPMS 
on existing loading racks. However, we note that the cross-referenced 
standards at 40 CFR 60.502(h) indicate that pressure must be monitored 
continuously as specified in 40 CFR 60.504a(d). In reviewing the final 
requirements, we determined that it was reasonable to allow facilities 
that have a pressure CPMS to use it for this compliance, but that 
additional language was needed to expressly provide pressure monitoring 
during performance tests or performance evaluations that we intended to 
allow. Therefore, we are adding an alternative monitoring provision at 
40 CFR 63.427(f) that allows pressure monitoring during performances 
tests or performance evaluations following the provisions in 40 CFR 
60.503(d) to determine that the system is appropriately designed and 
operated at or below a pressure of 18 inches of water during product 
loading as an alternative to using a pressure CPMS.
c. NESHAP Subpart BBBBBB
i. What did the EPA propose pursuant to CAA section 112(d)(6) for the 
area source gasoline distribution source category?
    Based on our technology review for loading racks at area sources, 
we proposed to lower the allowable TOC emission limit from 80 mg/L to 
35 mg/L for large bulk gasoline terminals in NESHAP subpart BBBBBB. We 
proposed that the 35 mg/L TOC emission limit would apply to loading 
racks controlled by thermal oxidation systems or flares. For thermal 
oxidation systems, we proposed continuous compliance with a temperature 
operating limit established as the lowest 3-hour average temperature 
from a compliant performance test and proposed enhanced provisions for 
flares to ensure good combustion efficiency. We proposed to allow the 
use of a ``flare monitoring alternative'' as an alternative to the 
temperature operating limit for thermal oxidation systems. For loading 
racks controlled by VRUs, we proposed to express this emission limit in 
terms of a concentration limit of 19,200 ppmv TOC as propane on a 3-
hour rolling average because this provides an equivalent emission limit 
that is directly enforceable with the common monitoring systems used 
for VRUs. To prevent dilution, we proposed that only vacuum breaker 
valves can be used to introduce ambient air into the VRU control 
system. For loading racks at small bulk terminals, we proposed to 
retain submerged filling currently required in NESHAP subpart BBBBBB.
    For bulk gasoline plants, we proposed to add requirements to use 
vapor balancing between gasoline cargo tanks and gasoline storage 
vessels for bulk gasoline plants with a gasoline throughput over 4,000 
gallons per day. We proposed to require pressure relief valves on fixed 
roof tanks used in vapor balancing to have opening pressures set no 
less than 2.5 psig.
ii. How did the technology review change for gasoline loading racks at 
area source gasoline distribution facilities?
    We did not revise our proposed technology review for bulk gasoline 
terminals. We revised the proposed vapor balancing provisions to apply 
to bulk gasoline plants that have an actual throughput of 4,000 gallons 
per day or more on an annual average basis rather than using maximum 
calculated design throughput. We also revised the vapor balancing 
storage tank provisions regarding the minimum pressure relief device 
opening pressure, reducing it from 2.5 psig to 18 inches of water (0.65 
psig).
iii. What key comments did the EPA receive and what are the EPA's 
responses?
    Comment: Several commenters supported the EPA's proposal to reduce 
the emission limit for gasoline loading racks at large bulk gasoline 
terminals from 80 mg/L TOC to 35 mg/L TOC, noting that control systems 
to meet 35 mg/L TOC are ``generally available'' and cost-effective. One 
commenter further noted that area source facilities are not large HAP 
emitters (by definition) and should not be subject to the 10 mg/L TOC 
emission limit that the EPA considered. Another commenter agreed that 
it is not cost-effective to require vapor collection and control for 
``small bulk gasoline terminals'' and provided cost estimates for four 
example small terminals. A couple commenters also suggested that the 
EPA underestimated the costs for ``large bulk gasoline terminals'' to 
meet a 10 mg/L emission limit, so the EPA should retain the proposed 35 
mg/L limit and not reduce it to 10 mg/L.
    Response: The EPA appreciates the support for reducing the TOC 
emission limit for gasoline loading racks at large bulk gasoline 
terminals from 80 mg/L to 35 mg/L. As discussed in our June 2022 
proposal, we agree that further reducing the emission limits for area 
source bulk gasoline terminals is not cost-effective (87 FR 35620; June 
10, 2022). We are finalizing the 35 mg/L TOC emission limit for large 
bulk gasoline terminals at area source gasoline distribution 
facilities.
    Comment: One commenter stated that the EPA significantly 
underestimated the economic impact of the proposed rule on small 
business energy marketers. Based on survey results presented in the 
comment, the commenter stated that dropping the current compliance 
threshold from a 20,000 gallon maximum daily design threshold to 4,000 
gallons would pull virtually every small bulk gasoline plant into vapor 
balancing requirements, forcing small energy marketers out of the 
wholesale gasoline market. The commenter stated that using a maximum 
daily design throughput as a threshold for compliance is not an 
accurate or meaningful method to control emissions from bulk gasoline 
plants, which may be assessed based on the size of the storage tank at 
the facility, and suggested the actual daily throughput averaged over a 
longer time period, like a month, is a better method to establish a 
compliance threshold without placing a heavier burden on small bulk 
gasoline plants than necessary.
    Response: We identified several states with these requirements and 
expected that many existing cargo tanks would be fitted with 
appropriate piping to accommodate vapor balancing, which would minimize 
the impacts of the proposed requirements. We note that the State 
requirements we reviewed each applied the vapor balancing requirement 
to bulk gasoline plants with daily throughputs of 4,000 gallons per day 
or more. In reviewing these requirements more closely, we found

[[Page 39324]]

that these daily averages were to be calculated on a monthly or annual 
average basis. When we evaluated the costs and cost effectiveness of 
requiring smaller bulk gasoline plants to use submerged loading and 
concluded that it was not cost-effective for them to do so, we based 
our analysis on the actual average throughput values, not design 
capacity values.
    We used the maximum calculated design throughput to use consistent 
terminology with how a facility determines their gasoline distribution 
facility type (e.g., bulk gasoline plant or bulk gasoline terminal). 
Based on previous analyses, we estimated that there were 5,913 bulk 
gasoline plants, 1,715 of which already had vapor balancing for both 
deliveries and loading. We estimated that 270 bulk gasoline plants 
would need to add vapor balancing to either deliveries or loading, and 
2,095 bulk gasoline plants would need to add vapor balancing to both 
deliveries and loading. The remaining 1,833 bulk gasoline plants were 
projected to be exempt from the vapor balancing requirement since their 
throughput is less than 4,000 gallons per day. Thus, we projected that 
at least 30 percent of bulk gasoline plants could use the throughput 
exemption. Consistent with our analysis and the State rule requirements 
used to support our proposal (87 FR 35621; June 10, 2022), we are 
revising the 4,000 gallon per day threshold to be based on an actual 
throughput basis. We note that table 1, item 1(ii), of NESHAP subpart 
BBBBBB contains a provision to calculate the average daily throughput 
of gasoline storage tanks using an annual averaging time. In addition, 
table 2 of NESHAP subpart BBBBBB uses annual averaging time to 
determine control requirements for bulk gasoline terminals. Therefore, 
because the State requirements we reviewed used an annual averaging 
time, and because NESHAP subpart BBBBBB already contains provisions 
using an annual averaging time, we are finalizing the requirement to 
use an annual averaging time. Additionally, we selected the annual 
averaging time because we expected an annual average to be more 
consistent, with less chance of facilities fluctuating from below to 
above the threshold than when a monthly or daily averaging time is 
used.
    We also added requirements to maintain records of gasoline 
throughput and the time frame in which to add vapor balancing controls 
if a bulk gasoline plant newly triggers the requirement. With the 
revision to use actual throughput rather than capacity, we determined 
that the economic impacts we estimated at proposal for bulk gasoline 
plants are reasonable and accurate. That is, we expected that a 
significant number of bulk gasoline plants will be below the 
applicability threshold we proposed, but our evaluations were based 
largely on applicability to State rules and other assessments that were 
based on actual throughputs. Therefore, we agree that we likely 
understated the impact of the proposed provisions for vapor balancing 
at bulk gasoline plants based on a maximum calculated design 
throughput. However, with the revision of the thresholds to an actual 
throughput basis, our previous projections of the number of facilities 
impacted by the vapor balancing requirements are now accurate and 
commensurate with the final rule requirements. Therefore, we are 
finalizing the proposed vapor balancing requirements, but only for bulk 
gasoline plants that have an actual throughput of 4,000 gallons per day 
assessed on an annual average basis.
    Comment: Some commenters stated that the pressure relief device 
setting of no less than 2.5 psig for fixed roof storage tanks would 
exceed safe pressure for some storage tanks and should be removed from 
both the vapor balancing and fixed roof storage tank requirements in 
proposed NESHAP subpart BBBBBB.
    Response: We understood most conservation (pressure relief) vents 
on atmospheric tanks use a release pressure of 2.5 psig or less. 
Considering the storage of gasoline, which has a partial pressure of 
over 3 psia, it would seem that fixed roof tanks would vent frequently 
if the conservation vents open at a pressure under 2.5 psig. In the 
proposal, we therefore expected 2.5 psig to be a reasonable requirement 
for pressure relief devices used for vapor balancing and on fixed roof 
storage tanks. However, based on our research concerning this comment, 
we now understand that ``atmospheric tanks'' are generally designed to 
operate between atmospheric pressure up to 2.5 psig and that ``low 
pressure tanks'' are designed to operate between 2.5 and 15 psig. Thus, 
the proposed requirement would be readily achievable for low-pressure 
tanks, but pressure relief devices on atmospheric tanks would generally 
begin to relieve pressure below 2.5 psig (typically between 0.8 and 1.5 
psig). Essentially, the proposed requirement would require storage 
tanks at bulk gasoline plants subject to the proposed vapor balancing 
requirement and small, low throughput tanks at area source gasoline 
distribution facilities to replace some atmospheric storage tanks with 
low-pressure tanks. It is unclear what fraction of existing gasoline 
storage tanks are of low-pressure design that may be able to meet this 
pressure requirement, but it is expected that a significant number of 
existing gasoline storage tanks are atmospheric tanks and would thus 
need to be replaced to meet this requirement. We had not considered 
these additional costs at proposal. Equipment costs are estimated to be 
about $50,000 per tank, so installed costs (including removal of the 
old tank) are about $100,000 per tank not considering business 
interruptions during tank replacement. We project that, for a 10,000 
gallon per day throughput bulk gasoline plant, the vapor balancing 
requirement with a tank replacement to meet the 2.5 psig minimum 
pressure relief limit would have cost $70,000 per ton of HAP reduced. 
This would not be cost-effective for the HAP emitted by these sources. 
The existing requirements in the gasoline distribution rules require 
that no pressure relief device open at pressures less than 18 inches of 
water, which is 0.65 psia. Based on this existing requirement, we 
expect that atmospheric storage vessels used at gasoline distribution 
facilities would not have devices opening at less than 0.65 psia. 
Therefore, we agree with commenters that the 2.5 psig requirement for 
pressure relief devices associated with fixed roof tanks and vapor 
balancing is not technically feasible without replacing numerous 
atmospheric storage tanks. We determined that replacing these 
atmospheric storage tanks is not cost-effective for the HAP emitted by 
these sources. Because our proposed standards required the vapor 
balancing system to be operated at pressures less than 18 inches of 
water column with no pressure relief device opening at pressures less 
than 18 inches of water column, and because fixed roof storage tanks 
are part of the vapor balancing system, we are finalizing that the 
appropriate minimum pressure relief device opening pressure for fixed 
roof storage tanks should be 18 inches of water column (0.65 psia).
    Comment: Several commenters recommended that area sources using 
thermal oxidation systems should be able to utilize alternative 
monitoring protocols to temperature continuous parametric monitoring 
systems (CPMS) currently in NESHAP subpart BBBBBB. While temperature 
CPMS are required for major sources complying with the 10 mg/L TOC 
emission limit, according to the commenters, a temperature CPMS is not 
needed to demonstrate compliance with a 35 mg/L limit. The commenters

[[Page 39325]]

suggested that there would be no, or very small, emission reductions 
gained by a temperature CPMS, the emission reductions would not be 
worth the costs, and there would be additional secondary emissions 
resulting from increased fuel use to maintain temperatures during 
periods of low loading rates. The commenters stated that stack 
temperature monitoring is inappropriate and unnecessary to meet a 35 
mg/L TOC limit. Temperatures often decrease during periods of low 
loading, but these low temperatures do not signal poor combustion 
efficiency, rather, low heat release rates due to lower flows. One 
commenter further indicated that temperature is not indicative of 
thermal oxidation system performance, providing a 2006 performance 
test, which, according to the commenter, demonstrated that high 
combustion efficiency and low emissions were achieved at low (as well 
as high) temperatures. The commenters suggested that the EPA should 
allow for the use of the existing thermal oxidation system monitoring 
alternative in NESHAP subpart BBBBBB.
    According to the commenters, the EPA is on record indicating that 
pilot flame monitoring is sufficient for area sources [to meet 80 mg/L] 
and has not provided justification why it is not sufficient now. One 
commenter also stated that the EPA provided no justification as to why 
the flare requirements are applicable to these thermal oxidation 
systems or why they provide better assurance than the current 
alternative provisions. The commenter also stated that the cost impacts 
for this proposed ``flare'' alternative were understated. The commenter 
suggested that, if the EPA believes more continuous monitoring of 
proper operation of the air-assist blower and vapor line valve is 
needed, the EPA could revise existing language at 40 CFR 
63.11092(b)(1)(iii)(B)(2)(ii) to require only automated alarms and 
shutdown (rather than to perform daily visual observations).
    One trade organization requested source test data from member 
facilities that are subject to emission limits above 10 mg/L and that 
do not use auxiliary fuel. Over 60 source tests were submitted and each 
one showed emissions meeting the 35 mg/L limit. The commenter concluded 
that this demonstrates that gasoline vapors are highly combustible and 
auxiliary fuel is not needed.
    Response: While several commenters appeared to oppose the 
temperature operating limit, we note that the existing NESHAP subpart 
BBBBBB also has a temperature operating limit as a compliance option. 
We disagree with the commenters suggesting that temperature is not a 
good indicator of performance. Based on the data provided by the 
commenter, while there are periods of high combustion efficiency and 
low emissions when the temperature is low, the temperature versus 
emission rate and temperature versus efficiency graphs showed that all 
exceedances of 35 mg/L (or control efficiencies less than 98 percent) 
were at temperatures under 900 [deg]F. Thus, one can conclude from the 
data presented that operating at a minimum combustion temperature of 
900 [deg]F would ensure that the source would meet the 35 mg/L emission 
limit at all times. We therefore conclude that setting a minimum 
operating temperature is a reasonable continuous compliance method.
    Second, we note that we proposed an alternative compliance option 
to the temperature operating limit. The key difference between the 
existing and our proposed alternative to temperature monitoring in 
NESHAP subpart BBBBBB is that the proposed alternative is designed to 
ensure that the combustion unit is not over assisted. We proposed this 
more rigorous compliance alternative because the applicable emission 
limit was lowered from 80 mg/L to 35 mg/L and due to our improved 
understanding of air-assisted combustion devices gained over the past 
10 years. The proposed monitoring alternative is similar to the 
previous NESHAP subpart BBBBBB requirements with respect to continuous 
pilot flame monitoring. However, we found that the previous NESHAP 
subpart BBBBBB requirements, which included daily visual inspection to 
verify the proper operation of the air-assist blower and the vapor line 
valve, would not ensure good combustion during periods of low flow if 
the air blower is set at a high, fixed level to prevent smoking during 
periods of high gasoline vapor flow. That is, many of the vapor 
combustors used at gasoline distribution facilities are essentially 
enclosed air-assisted flares and the existing requirements in NESHAP 
subpart BBBBBB did not prevent over-assisting the combustor during low 
flow events. Therefore, we proposed a more substantive alternative to 
direct temperature monitoring to ensure that these combustors are 
meeting the applicable emission limit at all times, including periods 
of low gasoline vapor flow.
    While the proposed requirements are more substantive, there are 
parallels with the existing requirements. For example, proper 
functioning of the air-assist blower could be simply an assessment of 
whether the blower is on or not. This requirement would not prevent 
over-assisting the combustor. However, if a multispeed air blower is 
used, proper functioning of the air-assist blower could consider that 
the air-assist rates are low during low gasoline vapor flow rates and 
higher at higher vapor flow rates, which could help to prevent over-
assisting. Proper functioning of the vapor line valve should prevent 
very low flows to the combustion unit, since the vapor line valve would 
remain closed until a set pressure is exceeded. Without the vapor line 
valve, the vapor flow rate could approach zero, such that the allowable 
air-assist rate would also approach zero. However, with the vapor line 
valve, the minimum vapor line flow is a step function above zero. This 
means the air-assist blower can remain on at some low flow setting 
because gasoline vapor flow will always be some step above zero based 
on the pressure setting for the vapor line valve. One can consider the 
proposed requirements to be a more detailed requirement of the 
provisions in 40 CFR 63.11092(b)(1)(iii)(B)(2)(ii) ``. . . the proper 
operation of the assist-air blower and the vapor line valve.'' For low 
gasoline vapor flows, low air-assist rates are needed to prevent over-
assisting the combustor. For higher gasoline vapor flows, higher air-
assist rates may be needed to prevent smoking from the combustor. Thus, 
in context of the proposed rule, proper operation of the air-assist 
blower would translate to using an appropriate air-assist rate relative 
to the gasoline vapor flow rate, and the proper operation of the vapor 
line valve should prevent very low flows to the combustion unit, 
allowing a lower air-assist flow rate to be determined.
    We proposed to allow an initial assessment of net heating values of 
gasoline vapors to see if auxiliary fuel is needed to meet the 
combustion zone net heating value. For unassisted or air-assisted 
flares, we expect gasoline vapors will routinely exceed the minimum 
required combustion zone net heating value. The combustion zone net 
heating value operating limit becomes more important if steam assist is 
used. For gasoline distribution facilities that use air-assisted 
thermal oxidation systems or flares, it is possible that the air-assist 
rate may be too high during periods of low gasoline vapor flow and 
overdilute the gasoline vapors prior to effective combustion. We 
proposed that facilities could use an assessment of the flow rate when 
only loading one cargo tank to project the low flow rate by which to 
assess whether the air-assist

[[Page 39326]]

flow rate is low enough not to over-assist the flare during low flow 
events. As noted in response to comments regarding the monitoring 
provisions for thermal oxidation systems and flares in section 
III.A.1.a.iii.C of this preamble, we have revised and clarified the 
requirements for the initial assessment of net heating values at 40 CFR 
60.502a(c)(3)(vii) and allow owners or operators to establish a minimum 
gasoline loading rate operating limit, in addition to a minimum ratio 
of gasoline to total product loading rate, that can be used to ensure 
vapor flow rates are high enough for a set air-assist rate to 
demonstrate compliance with the NHV<INF>dil</INF> operating parameter. 
If the air-assist rate is too high, facilities can lower the air-assist 
rate or add auxiliary fuel according to the provisions in 40 CFR 
60.502a(c)(3)(viii) to ensure that enough heat release is provided to 
ensure high combustion efficiencies at low flow rates.
    We appreciate the data collected and provided by the commenter that 
showed many facilities could meet the 35 mg/L TOC emission limit 
without the use of auxiliary fuel. We expect some facilities will 
conduct sampling of their heat content and assess their air addition 
rates and determine that no additional fuel is needed. Thus, we expect 
many facilities will be able to meet the 35 mg/L TOC emission limit 
without auxiliary fuel. However, the performance tests are typically 
done with high loading rates, and may not adequately reflect the 
performance for air-assisted combustion units when operated at low 
loading rates. Therefore, we are finalizing requirements to either 
continuously monitor the net heating value of the vapors discharged to 
the flare or thermal oxidation system or to perform an initial 
assessment to determine a minimum gasoline loading rate operating limit 
that ensures high combustion efficiencies. As proposed, facilities that 
cannot meet the NHV<INF>dil</INF> operating limit based on the minimum 
gasoline loading rate operating limit can determine a minimum auxiliary 
fuel addition rate (perhaps with a dual speed or variable speed blower) 
needed to ensure good combustion efficiencies at these lower flow rates 
that might not be well-represented during the performance test. Without 
this assessment, we remain unconvinced that the mere presence of a 
pilot flame, along with daily inspections of the vapor line valve and 
air blower, are adequate to ensure a 35 mg/L TOC emission limit is met 
at all times.
    Comment: One commenter recommended that sources using VRU should be 
able to implement alternative monitoring protocols as set forth under 
40 CFR 63.11092(b)(1)(i)(B)(1)(i)-(iii). According to the commenter, 
the EPA has not referenced any data suggesting that the alternative 
monitoring options would not be sufficient to ensure compliance with a 
35 mg/L (or 19,200 parts per million by volume (ppmv) as propane) TOC 
emission limit. Alternatively, if the EPA believes that CEMS must be 
required at all bulk gasoline terminal facilities subject to NESHAP 
subpart BBBBBB, then the EPA should allow the alternative monitoring 
protocols for periods of shutdown or repairs to CEMS rather than 
requiring the loading racks to be taken out of service. A few 
additional commenters did not object to the requirement to use a CEMS, 
but similarly stated that the current alternative monitoring protocols 
should be allowed for periods of shutdown or repairs to CEMS. According 
to the commenter, there would be cost impacts that were not considered 
by the EPA if no alternative is provided when the CEMS is inoperable or 
out-of-control.
    Response: We proposed the concentration limit specifically so that 
a CEMS could be used to demonstrate continuous compliance with the TOC 
emission limit for VRU. We proposed to require CEMS for all rules, 
including NESHAP subpart BBBBBB, because a CEMS can directly assess 
compliance with the emission limit and the design and operating 
parameters cannot provide this direct assessment. However, we did not 
estimate costs for back-up CEMS nor facility disruptions for periods of 
CEMS outages. Therefore, we sought to provide an alternative to using a 
CEMS that could be used for limited periods of CEMS outages, but not 
one that could be used indefinitely as an ongoing alternative to a 
CEMS.
    In the cited alternative monitoring protocols in NESHAP subpart 
BBBBBB, the regeneration cycles were based largely on design 
considerations, with monthly measurements of the carbon bed outlet to 
ensure breakthrough had not occurred near the end of an adsorption 
cycle. With facilities using CEMS, they will have recent data on 
regeneration cycle times (that can be normalized by product loading 
quantities) by which to base the regeneration cycle times to use during 
CEMS outages. This method follows many of the requirements in the 
existing NESHAP subpart BBBBBB alternative, but the operating 
parameters are based on those used to meet the emission limit when the 
CEMS was operating, which provides better assurance that the VRU is 
meeting the emission limit than cycle times and other operating 
parameters that are based solely on design considerations. We are 
providing specific provisions on how cycle times and other operating 
limits will be established based on operations just prior to the CEMS 
outages. We are setting a maximum number of hours for which the 
alternative monitoring method can be used at 240 hours in a calendar 
year. We consider this time period to be adequate to conduct 
maintenance on or to replace the CEMS, as needed. Because the operating 
parameters are specific to recent carbon adsorption system operating 
conditions, we determined that this alternative would provide 
compliance assurance during a 2-week period. We also selected this time 
period to emphasize that this is a limited use alternative and that 
CEMS should be used as the compliance method for all VRU. While most 
commenters requesting an alternative to CEMS cited the NESHAP subpart 
BBBBBB provisions, we find this limited alternative to the use of a 
CEMS would also provide adequate short-term compliance assurance for 
VRUs meeting more stringent emission limits in NESHAP subpart R and 
NSPS subpart XXa. Therefore, we are finalizing this alternative in all 
of the gasoline distribution rules as a temporary means to demonstrate 
compliance during periods of CEMS outages.
iv. What is the rationale for the EPA's final approach for the 
technology review?
    We are finalizing the loading rack emission limits for area source 
bulk gasoline terminals as proposed. Because many of the specific 
monitoring requirements cross-reference provisions or contain similar 
provisions as in NSPS subpart XXa, revisions related to allowing the 
exclusion of methane from measured TOC, use of vacuum purge gas for 
VRUs, revisions to the definition of 3-hour rolling average, and 
associated revisions to the recordkeeping and reporting requirements 
also impact the final requirements for gasoline loading operations at 
area source facilities. Our rationale for these revisions is summarized 
in section III.A.1.a.iv of this preamble.
    We are revising the proposed requirements for vapor balancing at 
bulk gasoline plants. First, for reasons discussed in section 
III.A.1.c.iii of this preamble, we are revising the threshold for bulk 
gasoline plants required to use vapor balancing from a maximum 
calculated design throughput of 4,000 gallons per day or more to an 
annual average actual throughput of 4,000 gallons per day or more, to 
better align

[[Page 39327]]

with the analysis conducted regarding the cost effectiveness of this 
threshold and other provisions in NESHAP subpart BBBBBB. We are also 
revising the minimum pressure setting for fixed roof storage vessels 
used in vapor balancing from 2.5 psig to 18 inches of water column.
    For reasons as explained in section III.A.1.b.iv, we specifically 
referenced vapor tight provisions at 40 CFR 63.422(c) and (e) in 
proposed item 1(g) of table 2 to subpart BBBBBB because we did not 
intend to require facilities subject to NESHAP subpart BBBBBB to 
install pressure CPMS on existing loading racks. However, as discussed 
in section III.A.2.b.iii of this preamble, we received comment that the 
cross-referenced sections to the NESHAP subpart R requirements were 
incomplete and incorrect. As such, we are finalizing the vapor-
tightness requirements by cross-referencing the provisions in NSPS 
subpart XXa. Therefore, similar to the final requirements we added in 
NESHAP subpart R, we are adding a monitoring alternative at 40 CFR 
63.11092(h) to allow pressure measurements made during performances 
tests or performance evaluations following the provisions in 40 CFR 
60.503(d) as an alternative to using a pressure CPMS to determine that 
the system is appropriately designed and operated at or below a 
pressure of 18 inches of water during product loading. We are also 
adding a cross-reference to 40 CFR 63.11092(h) in item 1(f) of table 2 
(corresponding to proposed item 1(g) of table 2) to clarify that 
existing sources under NESHAP subpart BBBBBB have the option to either 
install a pressure CPMS or to periodically verify the appropriate 
design and operation of the system by measuring pressure of the system 
during performance tests or evaluations following the requirements in 
40 CFR 60.503(d).
    We are maintaining the compliance methods, as proposed, including 
provision for thermal oxidation systems to either monitor combustion 
zone temperature or use the flare monitoring alternative and for VRU to 
use a CEMS. However, in response to comments, as discussed in section 
III.A.1.c.iii of this preamble, we are providing a limited, short-term 
alternative to using a CEMS for bulk gasoline terminals using a VRU 
that can be used for periods of CEMS outages.
2. Standards for Cargo Tank Vapor Tightness
a. NESHAP Subpart R
i. What did the EPA propose pursuant to CAA section 112(d)(6) for the 
major source gasoline distribution source category?
    The EPA proposed a graduated vapor tightness certification 
requirement ranging from 0.50 to 1.25 inches of water pressure drop 
over a 5-minute period, depending on the cargo tank compartment size 
for gasoline cargo tanks. The existing requirement in NESHAP subpart R 
is a graduated vapor tightness certification requirement ranging from 
1.0 to 2.5 inches of water pressure drop over a 5-minute period, 
depending on the cargo tank compartment size for gasoline cargo tanks. 
We proposed that cargo tanks certified prior to 3 years from the 
promulgation date would have to certify to the existing levels and that 
cargo tanks certified on or after 3 years from the promulgation date 
would have to certify to the proposed lower levels.
ii. How did the technology review change for gasoline cargo tanks at 
major source gasoline distribution facilities?
    We did not revise our proposed technology review for cargo tank 
vapor tightness requirement. However, we revised the timing of the new 
requirements so that all cargo tanks undergoing annual certification 
would be certified at the lower allowable pressure drop level within 3 
years of promulgation of the final rule.
    iii. What key comments did the EPA receive and what are the EPA's 
responses?
    We received general support for the proposed cargo tank vapor 
tightness requirements, particularly the harmonizing of requirements 
across the three rules (NESHAP subparts R and BBBBBB and NSPS subpart 
XXa).
    Comment: One commenter stated that compliance with a CAA section 
112(d) rule must be ``as expeditiously as practicable'' and ``in no 
event later than 3 years after the effective date of such standard.'' 
With respect to cargo tanks, the commenter stated that the Agency did 
not demonstrate why 3 years was needed to comply with the revised vapor 
tightness requirements. Specifically, the commenter noted that, if 3 
years are provided before the new vapor tightness certification limits 
become effective and an additional year is then required for the entire 
fleet of gasoline cargo tanks to be certified at that lower level, then 
the proposal is effectively providing a 4-year compliance schedule, 
which is not provided under CAA section 112(d). The commenter 
recommended that no more than 2 years be provided to implement the new 
limits and no more than 3 years provided to implement and certify the 
cargo tanks at that lower level.
    Response: For cargo tanks, we agree that compliance with the 
revised vapor tightness requirements and annual certification can be 
implemented in 3 years. Therefore, within 3 years from the promulgation 
date of the rule, we are requiring that all cargo tanks loaded must be 
certified at the lower vapor tightness values. That way, the entire 
fleet of gasoline cargo tanks would have certifications at the lower 
level within 3 years of the promulgation date of this final rule rather 
than requiring that certifications at the lower level begin at 3 years 
after the promulgation date. Therefore, we have eliminated provisions 
that would allow an additional year to test and fully implement the new 
cargo tank vapor tightness requirements.
iv. What is the rationale for the EPA's final approach for the 
technology review?
    We are finalizing the graduated vapor tightness certification 
requirement ranging from 0.50 to 1.25 inches of water pressure drop 
over a 5-minute period, depending on the cargo tank compartment size 
for gasoline cargo tanks, as proposed. We are finalizing a compliance 
schedule that ensures that all gasoline cargo tanks are certified at 
the lower levels within 3 years of the promulgation date of the final 
rule because the CAA requires compliance as expeditiously as 
practicable and no later than 3 years after the promulgation date.
b. NESHAP Subpart BBBBBB
i. What did the EPA propose pursuant to CAA section 112(d)(6) for the 
area source gasoline distribution source category?
    The EPA proposed a graduated vapor tightness certification 
requirement ranging from 0.50 to 1.25 inches of water pressure drop 
over a 5-minute period, depending on the cargo tank compartment size 
for gasoline cargo tanks to harmonize gasoline cargo tank requirements 
with those in NESHAP subpart R.
ii. How did the technology review change for gasoline cargo tanks at 
area source gasoline distribution facilities?
    We did not revise our proposed technology review for cargo tank 
vapor tightness requirement. However, since we cross-reference the 
vapor-tight certification requirements in NESHAP

[[Page 39328]]

subpart R, the timing of the final requirements was revised such that 
gasoline cargo tanks must be certified at the lower levels in order to 
be loaded no later 3 years from the promulgation date of the final 
rule.
iii. What key comments did the EPA receive and what are the EPA's 
responses?
    Comment: One commenter noted that the revisions to table 2 result 
in NESHAP subpart BBBBBB no longer expressly requiring the annual 
certification testing, in that table 2 item 1(g) now references 
paragraphs 40 CFR 63.422(c) and (e), neither of which specify 
conducting the annual certification test. The commenter recommended 
that the text of table 2 item 1(g) be edited to read, ``. . . into 
vapor-tight gasoline cargo tanks using the procedures specified in 
Sec.  63.11094(b).''
    Response: We agree that the references to 40 CFR 63.422(c) and (e) 
are incorrect. However, 40 CFR 63.11094(b) addresses only recordkeeping 
requirements and not the requirements to not load non-vapor tight cargo 
tanks. Upon further review, the provisions in table 2, item 1(g) were 
intended to be similar to the current requirements in item 1(e). 
Therefore, we are revising the entry in table 2, proposed item 1(g) 
(which is now 1(f) in the final rule) to reference the NSPS subpart XXa 
requirements at 40 CFR 60.502a(e) through (i) and are also adding a 
cross-reference to 40 CFR 63.11092(g) and (h), which specifies the test 
methods for the annual certification and alternative monitoring 
requirements for pressure of the loading rack system, respectively. In 
addition, we are revising the provisions in table 2, item 2(c) to limit 
loading to vapor-tight gasoline cargo tanks using the procedures 
specified in 40 CFR 60.502a(e) and adding a cross reference to 40 CFR 
63.11092(g).
iv. What is the rationale for the EPA's final approach for the 
technology review?
    We are finalizing the graduated vapor tightness certification 
requirement ranging from 0.50 to 1.25 inches of water pressure drop 
over a 5-minute period, depending on the cargo tank compartment size 
for gasoline cargo tanks, as proposed. We are revising the entry in 
table 2, items 1(f) and 2(c), to reference the correct NSPS subpart XXa 
requirements and also adding a cross-reference to 40 CFR 63.11092(g), 
which specifies the test methods for the annual certification. Through 
these cross-references, we are finalizing requirements that 
certification of a gasoline cargo tank at the lower levels be conducted 
within 3 years from the promulgation date of the final rule to ensure 
that all gasoline cargo tanks are certified at the lower levels within 
3 years of the promulgation date of the final rule because the CAA 
requires compliance as expeditiously as practicable and no later than 3 
years after the promulgation date.
c. NSPS Subpart XXa
i. What did the EPA propose pursuant to CAA section 111 for new, 
modified, or reconstructed bulk gasoline terminals?
    The EPA proposed a graduated vapor tightness certification 
requirement ranging from 0.50 to 1.25 inches of water pressure drop 
over a 5-minute period, depending on the cargo tank compartment size 
for gasoline cargo tanks to harmonize gasoline cargo tank requirements 
with those in NESHAP subparts R and BBBBBB.
ii. How did the NSPS review change for gasoline cargo tanks at new, 
modified, or reconstructed bulk gasoline terminals?
    We did not revise our proposed NSPS review for cargo tank vapor 
tightness requirement.
iii. What key comments did the EPA receive and what are the EPA's 
responses?
    We received general support for the proposed cargo tank vapor 
tightness requirements, particularly the harmonizing of requirements 
across the three rules (NESHAP subparts R and BBBBBB and NSPS subpart 
XXa).
iv. What is the rationale for the EPA's final approach for the NSPS 
review?
    For reasons detailed in our June 2022 proposal (87 FR 35622; June 
10, 2022), we are finalizing the graduated vapor tightness 
certification requirement ranging from 0.50 to 1.25 inches of water 
pressure drop over a 5-minute period, depending on the cargo tank 
compartment size for gasoline cargo tanks, as proposed. We are 
finalizing requirements, as proposed, that all gasoline cargo tanks 
loaded at gasoline loading rack affected facilities subject to NSPS 
subpart XXa must be certified at the lower levels upon startup of the 
affected facility, as required under section 111 of the CAA. We are 
clarifying in 40 CFR 60.502a(e) that these provisions apply to the 
``gasoline loading rack affected facility'' and that the applicable 
vapor-tight gasoline cargo certification methods are in 40 CFR 
60.503a(f), consistent with the definition of ``vapor-tight gasoline 
cargo tanks'' in 40 CFR 60.501a. We are also clarifying that if the 
previous contents of a cargo tank are not known, you must assume that 
cargo tank is a gasoline cargo tank. These revisions are being made to 
be consistent with the nomenclature revisions for the loading racks as 
described in section III.A.1.iv of this preamble. These revisions also 
help clarify the requirements that ensure loading occurs only in vapor-
tight gasoline cargo tanks as defined in NSPS subpart XXa.
3. Standards for Gasoline Storage Vessels
a. NESHAP Subpart R
i. What did the EPA propose pursuant to CAA section 112(d)(6) for the 
major source gasoline distribution source category?
    The EPA proposed additional fitting requirements for storage 
vessels with external floating roofs as specified in 40 CFR 
60.112b(a)(2)(ii). We also proposed requirements for storage vessels 
with internal floating roofs to maintain the concentrations of vapors 
inside a storage vessel above the floating roof to less than 25 percent 
of the LEL. We proposed test method procedures for determining the LEL 
inside a storage vessel above the internal floating roof and 
corresponding recordkeeping and reporting requirements.
ii. How did the technology review change for gasoline storage vessels 
at major source gasoline distribution facilities?
    We did not revise our proposed technology review for storage 
vessels. However, we have made minor revisions to the test method 
procedures associated with the 25 percent of the LEL level.
iii. What key comments did the EPA receive and what are the EPA's 
responses?
    Comment: Several commenters opposed the 25 percent of the LEL level 
for various reasons. Two commenters stated that the EPA did not 
adequately demonstrate that LEL monitoring is an effective defect 
detection practice, and it should not be required. Two commenters 
stated that the EPA evaluated LEL as a monitoring enhancement, but 
proposed it as a standard and did not adequately identify controls, 
costs, or emission reductions for this standard. To assess if the LEL 
monitoring is warranted, the commenters recommended that the EPA fully 
account for costs of replacing the internal floating roof, not just the 
cost of

[[Page 39329]]

monitoring. One commenter cited the NSPS subpart Kb final rule preamble 
(52 FR 11420; April 8, 1987) that stated that ``[t]he Agency is not 
aware of any method by which an annual concentration measurement could 
be used to establish the condition of the control equipment.'' 
According to the commenters, the EPA has not provided sufficient data 
to alter that conclusion and should withdraw the proposed LEL 
monitoring requirement.
    Response: As part of the notice of data availability (87 FR 49795; 
August 12, 2022) the EPA provided the background information used in 
the LEL analysis. It is clear that internal floating roofs that had 
visible inspection issues (e.g., liquid on top of the floating roof) 
had high LEL concentrations in the headspace (well over 25 percent of 
the LEL) and those that did not have visible inspection issues had 
lower LEL concentrations (generally well below 25 percent of the LEL). 
Our emission estimates from various storage vessel requirements assume 
proper seals and other equipment are in-place and operating as 
required. If these controls are not operating as intended, the 
emissions from these storage vessels can be much higher. We found that 
the visual inspections are subjective and may, at times, not be 
performed well. For example, although a hired contractor for BP's 
Carson Refinery had reported no problems with the facility's 26 
floating roof storage vessels from 1994 to 2002, a South Coast Air 
Quality Management District inspection ``revealed that more than 80 
percent of the tanks had numerous leaks, gaps, torn seals, and other 
defects that caused excess emissions.'' \6\ Therefore, at proposal, we 
sought a less subjective means to verify performance of the floating 
roofs. We concluded that, given the preponderance of internal floating 
roof storage vessels in this source category, periodic LEL monitoring 
could be used to ensure the floating roofs are performing as intended.
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    \6\ Mokhiber, Russell. Multinational Monitor; Washington Vol. 
24, Iss. 4, (April 2003): 30.
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    We acknowledge that it is difficult to estimate the emission 
impacts of these LEL requirements because we do not have data on the 
number of poorly functioning floating roofs. We note that the storage 
vessel standards for NESHAP subpart R (as well as NESHAP subpart 
BBBBBB) rely heavily on the NSPS subpart Kb requirements. NSPS subpart 
Kb already requires repair of floating roofs that fail inspection and 
failure of the LEL monitoring triggers the same repairs. As such, we 
consider that these repairs are already required and the LEL 
requirement predominately makes the required inspections less 
subjective. In the worst-case scenario, a poorly operated internal 
floating roof can have emissions similar to those of a fixed roof 
storage vessel. In establishing the floating roof requirements, we 
already determined that installing a floating roof was cost-effective 
and that the costs of replacing a poorly functioning floating roof is 
not significantly different from the costs of retrofitting a fixed roof 
storage vessel. In our analysis, we used a 15-year life for the 
internal floating roof storage vessel. Thus, replacement of the 
internal floating roof every 15 years to ensure the emission reductions 
are achieved are inherent in the original costing assessment. 
Therefore, if an internal floating roof has failed to the point that 25 
percent of the LEL is exceeded, and the LEL level cannot be reduced 
without making repairs to the internal floating roof, we see no reason 
that these storage vessels should remain in service. Thus, we have 
already considered that replacement of the internal floating roof, if 
it has reached its end of life and is no longer reducing emissions as 
intended, is reasonable. While most poorly performing floating roofs 
can be repaired, rather than replaced, we maintain that replacing a 
failing internal floating roof is a reasonable requirement when repairs 
are ineffective.
    Since our statement in 1987 and as noted in our memorandum Review 
of LEL Testing Requirements for Internal Floating Roof Tanks, two 
States have developed rules that use LEL monitoring as a means to 
ensure that floating roofs are controlling emissions as intended. We 
note that these rules effectively set a maximum LEL limit that must be 
met--essentially an ``emission limitation,'' not just a monitoring 
requirement--and we modeled our proposed provision following these 
State rules. Furthermore, the National Fire Protection Association 
(NFPA) standard sets a maximum LEL limit of 25 percent for explosion 
prevention for internal floating roof storage vessels. Based on these 
developments, we concluded that establishing a maximum LEL level for 
internal floating roofs was reasonable and necessary when taking into 
account developments in practices, processes, and control technologies.
    Comment: Several commenters suggested that, if the EPA finalizes 
the LEL monitoring requirement, the following revisions be made to the 
LEL monitoring requirements as proposed:
    (1) Adopt higher LEL action levels: 50 percent for storage vessels 
installed prior to the effective date of the NSPS in part 60, subpart 
Kb, and 30 percent for storage vessels constructed, reconstructed or 
modified after the effective date of NSPS subpart Kb. According to the 
commenter, these limits would be more consistent with State 
requirements.
    (2) Allow calibration according to the manufacturer's 
recommendations, which may specify a different calibration gas (other 
than methane) or different calibration methods. Some instruments use 
docking stations for calibration, so cannot attach tubing.
    (3) Shorten LEL measurement period to a total of 10 minutes with 5 
minutes of recorded measurement data (concentrations do not change 
significantly and minimize time needed to be on the roof). In addition, 
facilities should have the option to record the highest measured value 
in lieu of recording a 5-minute rolling average or allow operators 
flexibility in their recordkeeping based on their internal systems and 
operations.
    (4) LEL should be a monitoring requirement, not a standard, so 
corrective action should be specified. Recommended that a failed LEL 
inspection should trigger the obligation to conduct a second 
confirmatory test within 30 days. If the second test shows that the 
initial inspection was an anomaly, no further action should be 
required. If the second inspection confirms an exceedance of the 
percentage LEL limit, then a third confirmatory test must be conducted 
within 30 days. If all inspections confirm the presence of gasoline 
vapors above the percentage LEL limit, then the tank must undergo 
repairs during the next regularly scheduled degassing event or 
inspected as specified in 40 CFR 63.1063(d)(1).
    (5) Remove the requirement that LEL measurements not be taken when 
wind speeds exceed 10 mph, as this is unworkable for some locations 
according to the commenters. One commenter recommended that the EPA 
only require regulated entities to use best efforts to block wind from 
the inspection area, document wind speed and direction, and use best 
engineering judgment regarding whether wind speed would affect the 
validity of the measurements. Another commenter suggested revising the 
provision to be the greater of 10 mph or the average monthly wind speed 
at the site.
    (6) State that the LEL monitoring is to be conducted while the 
internal floating roof is floating and with no product movement.
    Response: Regarding the action level of the LEL requirement (item 
1), we considered the State rule requirements

[[Page 39330]]

in establishing the threshold. However, we expect these rules were 
established prior to the NFPA standard establishing a 25 percent of the 
LEL limit. From the data we collected, there were very few measurements 
that exceeded 25 percent of the LEL that did not also exceed 50 percent 
of the LEL. Thus, when failures occurred, the LEL was often very high. 
In the LEL measurements that we have, there were cases where LEL levels 
of 30 percent were observed, but the facilities conducted corrective 
actions and reduced the emissions from these tanks. Based on these 
observations and considering the NFPA standard, we maintain that the 
appropriate limit for LEL levels for internal floating roof storage 
vessels is 25 percent.
    Regarding the calibration requirements (item 2), we agree that the 
use of other calibration gases is acceptable, provided appropriate 
correction factors are applied specifically to the calibration gas 
used. We have modified the monitoring method to incorporate this 
flexibility and added a corresponding recordkeeping and reporting 
requirement to indicate the gas used for calibration. However, we 
maintain that the calibration should be made with tubing attached. This 
will help to ensure no leaks in the tubing or other issues that may 
impact the LEL measurements when the tubing is attached. Therefore, we 
are not revising the proposed requirement to perform calibration with 
the tubing attached.
    Regarding reducing the duration of the LEL monitoring (item 3), we 
find that a 10-minute testing period (5-minute stabilization + 5 
minutes of reading) only provides one 5-minute average and is not as 
representative as the proposed 20-minute test period. However, if the 
LEL level is clearly exceeded in the first 5-minute average, we agree 
that continued monitoring is not necessary. Therefore, we have added a 
provision to the duration of the test provisions in 40 CFR 
63.425(j)(3)(ii) that allows discontinuing testing when one 5-minute 
average exceeds the 25 percent of the LEL level.
    Regarding an exceedance of the LEL requirement triggering 
corrective action (item 4), we note that the LEL monitoring does 
trigger corrective action as specified in 40 CFR 63.423(b)(2), ``A 
deviation of the LEL level is considered an inspection failure under 
Sec.  60.113b(a)(2) of this chapter or Sec.  63.1063(d)(2) and must be 
remedied as such.'' These sections require the storage vessels be 
repaired or taken out of service. We agree that re-monitoring should be 
done to confirm the repair has been successful, but some corrective 
action is needed on the floating roof prior to the second monitoring 
event. We do not agree with the commenter that the only corrective 
action needed is to re-monitor the LEL in the storage vessel. As such, 
we are revising 40 CFR 63.423(b)(2) to clearly require re-monitoring of 
the LEL to confirm repair. Specifically, we are adding the following 
sentence at the end of 40 CFR 63.423(b)(2): ``Any repairs made must be 
confirmed effective through re-monitoring of the LEL and meeting the 
level in this paragraph (b)(2) within the timeframes specified in Sec.  
60.113b(a)(2) or Sec.  63.1063(e), as applicable.''
    Regarding the maximum wind speed for the LEL monitoring test (item 
5), we reviewed average wind speed data for various locations and agree 
that the 10 mph limit may be too restrictive at some locations. 
However, the inspections should be performed when the wind speeds are 
typically low, as in the morning hours. After review of the annual 
average wind speeds, as well as daily fluctuations in wind speed,\7\ we 
considered whether the inspections could be performed at wind speeds 
under 15 mph, even when the annual average wind speed exceeds this 
level. After considering the comment and wind speed data, we agree to 
amend the wind speed requirement as follows: ``LEL measurements shall 
be taken when the wind speed at the top of the tank is 5 mph or less to 
the extent practicable, but in no case shall LEL measurements be taken 
when the sustained wind speed at top of tank is greater than the annual 
average wind speed at the site or 15 mph, whichever is less.''
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    \7\ <a href="https://windexchange.energy.gov/maps-data/325">https://windexchange.energy.gov/maps-data/325</a> for annual 
averages; <a href="https://www.visualcrossing.com/weather-data">https://www.visualcrossing.com/weather-data</a> for hourly and 
daily averages.
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    Regarding specifications for the floating roof when the LEL 
monitoring test is performed (item 6), the test should be conducted 
under normal operations and the roof should not be resting on the 
support legs. Thus, we agree with the commenter that the roof should be 
floating and that testing should not be conducted when either the 
storage vessel is empty or the roof landed on the support legs. We 
recognize potential safety issues may occur if the storage vessel is 
being filled and significant vapors are being expelled, but we do not 
want to forbid any movement of liquid during the test, as that may 
disrupt plant operations. Therefore, we have included language in the 
final rule that outline that the test ``. . . should be conducted when 
the internal floating roof is floating with limited product movement . 
. .''
    In considering the regulatory language proposed along with various 
needs to potentially re-monitor (due to high winds or to confirm 
repair) or to time inspections during periods of limited product 
movement, we found that the proposed requirement to monitor during each 
visual inspection required under 40 CFR 60.113b(a)(2) or 63.1063(d)(2) 
to be unnecessary. We intended that LEL monitoring would be conducted 
annually. While we anticipate that LEL monitoring would generally be 
conducted as part of the visual inspection requirements, mandating that 
they be conducted together will likely increase the number of LEL re-
monitoring events required. Therefore, we are also revising 40 CFR 
63.425(j)(1), as part of the revisions in response to these comments, 
to replace the proposed phrase ``during each visual inspection required 
under Sec.  60.113b(a)(2) or Sec.  63.1063(d)(2)'' with ``at least once 
every 12 months'' to clarify that the LEL monitoring is to be conducted 
annually, and that it may, but is not required to, be conducted during 
the visual inspection.
iv. What is the rationale for the EPA's final approach for the 
technology review?
    We are finalizing additional fitting requirements for storage 
vessels with external floating roofs as proposed because we determined 
these fitting requirements were cost-effective. We are also finalizing 
requirements for storage vessels with internal floating roofs to 
maintain the concentrations of vapors inside a storage vessel above the 
floating roof to less than 25 percent of the LEL, as proposed, because 
we determined that LEL monitoring is a development in practices that 
helps ensure the internal floating roof is operating effectively to 
reduce emissions. For reasons discussed in section III.A.3.a.iii of 
this preamble, we are making minor revisions to the proposed test 
method procedures for determining the LEL for storage vessels with 
internal floating roofs to clarify the test procedures and make them 
more flexible in response to public comments received. We are also 
adding and revising corresponding recordkeeping and reporting 
requirements.
b. NESHAP Subpart BBBBBB
i. What did the EPA propose pursuant to CAA section 112(d)(6) for the 
area source gasoline distribution source category?
    We proposed requirements for storage vessels with internal floating 
roofs to

[[Page 39331]]

maintain the concentrations of vapors inside a storage vessel above the 
floating roof to less than 25 percent of the LEL. We cross-referenced 
the proposed test method procedures for determining the LEL in NESHAP 
subpart R. We also proposed that fixed roof storage vessels must have 
pressure relief valves with opening pressures set no less than 2.5 
psig.
ii. How did the technology review change for gasoline storage vessels 
at area source gasoline distribution facilities?
    We did not revise our proposed technology review regarding the 
maximum 25 percent of the LEL for internal floating roof storage 
vessels. However, because we cross-reference the LEL testing 
requirements in NESHAP subpart R, there are minor revisions in the 
proposed LEL test method. We also revised the proposed fixed roof 
storage vessel provisions regarding the minimum pressure relief device 
opening pressure, reducing it from 2.5 psig to 18 inches of water (0.65 
psig).
iii. What key comments did the EPA receive and what are the EPA's 
responses?
    The key comments received regarding the LEL requirement are 
summarized in section III.A.3.a.iii of this preamble. The key comments 
received regarding the proposed 2.5 psig minimum pressure relief device 
opening pressure requirement for fixed roof storage vessels are 
summarized in section III.A.1.c.iii of this preamble.
iv. What is the rationale for the EPA's final approach for the 
technology review?
    We are finalizing requirements for storage vessels with internal 
floating roofs to maintain the concentrations of vapors inside a 
storage vessel above the floating roof to less than 25 percent of the 
LEL, as proposed, because we determined that LEL monitoring is a 
development in practices that helps ensure the internal floating roof 
is operating effectively to reduce emissions. For reasons discussed in 
section III.A.3.a.iii of this preamble, we are making minor revisions 
to the proposed test method procedures for determining the LEL for 
storage vessels with internal floating roofs to clarify the test 
procedures and make them more flexible in response to public comments 
received. We are also adding and revising corresponding recordkeeping 
and reporting requirements. For reasons discussed in section 
III.A.1.c.iii of this preamble, we are revising the minimum pressure 
setting for fixed roof storage vessels from 2.5 psig to 18 inches of 
water column.
4. Standards for Equipment Leaks
a. NESHAP Subpart R
i. What did the EPA propose pursuant to CAA section 112(d)(6) for the 
major source gasoline distribution source category?
    We proposed to require semiannual instrument monitoring of all 
equipment in gasoline service using either OGI according to proposed 
appendix K to 40 CFR part 60 (appendix K) or EPA Method 21. We also 
proposed to require repair of any leaks identified from a monitoring 
event or any leaks identified by AVO methods during normal duties.
    ii. How did the technology review change for equipment leaks at 
major source gasoline distribution facilities?
    There are no significant changes in our proposed technology review 
conclusions for equipment leaks at major source gasoline distribution 
facilities.
iii. What key comments did the EPA receive and what are the EPA's 
responses?
    Comment: Several commenters stated that the EPA's cost estimates 
for the proposed instrument monitoring provisions are understated for 
the reasons outlined below. If the EPA used the cost assumptions 
outlined below, the instrument cost effectiveness compared to AVO 
monitoring, using the EPA's emission estimates, would be $40,000 to 
$50,000 per ton HAP reduced, so instrument monitoring is not a cost-
effective alternative to AVO.
    <bullet> AVO inspections are part of normal walk around 
inspections, which would occur in the absence of the rule, so no cost 
savings should be applied for discontinuing monthly AVO inspections.
    <bullet> Method 21 monitoring costs are low.
    [cir] Startup cost for a Method 21 instrument monitoring program is 
about $15,000 to $30,000. According to the commenter, the EPA did not 
include connectors in the number of components in the startup cost 
estimate.
    [cir] Quarterly leak detection and repair (LDAR) monitoring costs 
are typically $10,000 to $20,000 per year (2 to 4 times the EPA 
estimate). This may be due, in part, to the EPA using an idealized 
component monitoring rate of 75 components an hour (commenter suggested 
80 percent of this rate, or 60 components per hour, is more realistic).
    [cir] Costs do not include license fees for enterprise software, 
which costs about $5,000 per year nor additional costs for monitoring 
difficult-to-monitor components (lifts, etc.).
    <bullet> Optical gas imaging (OGI) monitoring costs are low:
    [cir] Startup costs are likely $5,000 to $10,000, (not $1,000 to 
$1,500).
    [cir] Monitoring rate of 750 components an hour is idealized and at 
the minimum time per component specified in proposed appendix K. 
Considering viewing from 2 angles and required breaks specified in 
appendix K, a more realistic average monitoring rate is 192 components 
per hour.
    One commenter also stated that it may be technically infeasible 
with so many facilities having to do monitoring in 3 years. Also, the 
high demand for this service will likely increase costs.
    Response: Regarding the commenter's note that AVO inspections are a 
part of normal walk around inspections, the EPA recognizes that this 
type of equipment leak monitoring is part of standard operations at 
gasoline distribution facilities. However, through discussions with 
industry, it was understood that the routine walk throughs are not 
performed with the same level of thoroughness as the monthly 
inspections. Additionally, the monthly inspections require time to 
document the inspection. To account for these more thorough AVO 
inspections, the EPA determined that it is appropriate to apply a cost 
savings for discontinuing the monthly AVO inspection requirement.
    With respect to EPA Method 21 startup costs, we used the equipment 
counts for the model plant to estimate the startup costs. We assumed 
that only pumps and valves would need to be tagged, so connectors were 
excluded from the component count used in the startup costs. Facilities 
must know all equipment that need to be inspected via the current 
monthly AVO requirements, so the startup cost for Method 21 at gasoline 
distribution facilities is expected to be less than for facilities that 
have not had any LDAR requirements. As such, we consider the Method 21 
startup costs we estimated to be reasonable for these facilities.
    The EPA appreciates the commenter's feedback on lowering the 
monitoring rate used for Method 21 to 80 percent of the proposed value 
of 75 components per hour. The EPA notes that the comment does not 
include a rationale for why 80 percent of the proposed value is 
appropriate. The monitoring rate used in our analysis is based on 
discussions with LDAR contractors and is considered reasonable for 
these facilities.

[[Page 39332]]

    If an owner or operator decided to perform instrument monitoring 
in-house, then we recognize that a software license would need to be 
purchased to manage the LDAR program. In our analysis, however, we 
assumed that all instrument monitoring is performed by an external 
contractor based on the size of typical gasoline distribution 
facilities (i.e., considering equipment costs and number of equipment 
components to be monitored). We assumed that these contractors already 
have a software license for an LDAR management program and the LDAR 
contractor can output data for the facility in Excel or as a comma-
separated values (CSV) file. As such, we assumed the cost of using the 
license is already built into the contractor's LDAR monitoring cost.
    With respect to OGI startup costs, as noted previously, facilities 
must know all equipment that needs to be inspected via the current 
monthly AVO requirements, so the startup cost for OGI at gasoline 
distribution facilities is expected to be less than for facilities that 
have not had any LDAR requirements. We consider the OGI startup costs 
we estimated at proposal to be reasonable for these facilities.
    The commenter's feedback on the OGI monitoring rate was based on 
the proposed appendix K; however, in light of public comments, the EPA 
subsequently issued a supplemental proposal with revised requirements 
in appendix K. Therefore, the EPA reviewed the OGI monitoring rate used 
in the equipment leak model compared to the requirements in appendix K, 
as reflected in the supplemental proposal. The OGI monitoring rate in 
the equipment leaks model was kept at 750 components per hour, which 
accounts for the amount of time needed to view each component (assumed 
4 seconds per component based on the appendix K requirements in the 
supplemental proposal to view each component at 2 angles for 2 seconds 
per component per angle, and the breaks required for technicians, which 
require a 5-minute break after 30 minutes of viewing).
    Based on our updated cost analysis in 2021 dollars, we determined 
that savings from not conducting monthly AVO monitoring and the value 
of the product not lost offsets the cost of semiannual instrument 
monitoring. We also found that the incremental cost of semiannual 
instrument monitoring compared to annual instrument monitoring was 
$6,700 per ton of HAP reduced, which we consider to be reasonable. 
Therefore, we maintain that semiannual instrument monitoring is cost-
effective for major source gasoline distribution facilities. For more 
information regarding our revised costs analysis for instrument 
monitoring, see memorandum Updated Control Options for Equipment Leaks 
at Gasoline Distribution Facilities in Docket ID No. EPA-HQ-OAR-2020-
0371.
    With respect to the comment suggesting it may be technically 
infeasible to conduct monitoring in 3 years due to demand, we see no 
basis for this claim. The leak inspection service industry is mature 
and while there may be many gasoline distribution facilities, a 
semiannual monitoring requirement for these facilities will not overly 
stretch the capacity of the service providers. We provide up to 3 years 
to comply with the instrument monitoring requirements. Facilities may 
begin instrument monitoring prior to the end of the 3-year period to 
avoid any potential contractor supply issues if that is a concern.
iv. What is the rationale for the EPA's final approach for the 
technology review?
    We are finalizing the equipment leak requirements for major source 
gasoline distribution facilities as proposed because we determined that 
semiannual instrument monitoring is cost-effective for major source 
gasoline distribution facilities. Facilities will have 3 years from the 
promulgation date of the rule to comply with the semi-annual equipment 
leaks instrument monitoring requirement.
b. NESHAP Subpart BBBBBB
i. What did the EPA propose pursuant to CAA section 112(d)(6) for the 
area source gasoline distribution source category?
    We proposed to require annual instrument monitoring of all 
equipment in gasoline service using either OGI according to proposed 
appendix K or EPA Method 21. We also proposed to require repair of any 
leaks identified from a monitoring event or any leaks identified by AVO 
methods during normal duties.
ii. How did the technology review change for equipment leaks at area 
source gasoline distribution facilities?
    There are no significant changes in the proposed technology review 
conclusions for equipment leaks at area source gasoline distribution 
facilities.
iii. What key comments did the EPA receive and what are the EPA's 
responses?
    In addition to the general key comments received regarding the 
equipment leaks monitoring as summarized in section III.A.4.a.iii of 
this preamble, the following comment was received specific to area 
source gasoline distribution facilities:
    Comment: One commenter stated that the proposed LDAR requirement is 
particularly burdensome for bulk gasoline plants and pipeline pumping 
stations. These facilities have limited staff and are often remote. 
Also, many of the EPA's costs are assumed to be linear by number of 
components and some may be less linear, so the costs are further 
understated for these small facilities.
    Response: With respect to higher burden for bulk gasoline plants 
and pipeline pumping stations, our cost estimates for instrument 
monitoring have two elements. One element is fixed costs per monitoring 
event; the second element is variable costs associated with the number 
of equipment components monitored. When considering both of these cost 
elements, we agree that the overall cost of monitoring (on a per 
component basis) is higher for bulk gasoline plants and pipeline 
pumping stations than it is for bulk gasoline terminals and pipeline 
breakout stations. However, our cost estimates take this into account 
because they consider the fixed costs associated with having a 
contractor perform instrument monitoring.
    Based on our updated cost analysis in 2021 dollars, we determined 
that savings from not conducting monthly AVO monitoring and the value 
of the product not lost offsets the cost of annual instrument 
monitoring and results in a net cost savings compared to monthly AVO 
monitoring. We also found that the incremental cost of semiannual 
instrument monitoring compared to annual instrument monitoring was 
$12,500 per ton of HAP reduced, which we determined was unreasonable. 
Therefore, we maintain that annual instrument monitoring is cost-
effective for area source gasoline distribution facilities. For more 
information regarding our revised costs analysis for instrument 
monitoring, see memorandum Updated Control Options for Equipment Leaks 
at Gasoline Distribution Facilities in Docket ID No. EPA-HQ-OAR-2020-
0371.
iv. What is the rationale for the EPA's final approach for the 
technology review?
    We are finalizing the equipment leak requirements for area source 
gasoline distribution facilities as proposed because we determined that 
annual instrument monitoring is cost-effective for area source gasoline 
distribution facilities. Facilities will have 3 years from the 
promulgation date of the final

[[Page 39333]]

rule to comply with the annual equipment leak instrument monitoring 
requirement.
c. NSPS Subpart XXa
i. What did the EPA propose pursuant to CAA section 111 at new, 
modified, or reconstructed bulk gasoline terminals?
    We proposed to require quarterly instrument monitoring of all 
equipment in gasoline service using OGI according to proposed appendix 
K or quarterly instrument monitoring of pumps, valves, and pressure 
relief devices and annual monitoring of connectors using EPA Method 21. 
We also proposed to require repair of any leaks identified from a 
monitoring event or any leaks identified by AVO methods during normal 
duties.
ii. How did the NSPS review change for equipment leaks at new, 
modified, or reconstructed bulk gasoline terminals?
    There are no significant changes in the proposed BSER conclusions 
for equipment leaks at facilities subject to NSPS subpart XXa.
iii. What key comments did the EPA receive and what are the EPA's 
responses?
    Key comments received regarding the NSPS affected facility 
definition for the equipment leak monitoring requirements are 
summarized in section III.A.1.a.iii of this preamble. General comments 
received on the cost assumptions used in the equipment leaks analysis 
are summarized in section III.A.4.a.iii of this preamble.
    Comment: Several commenters stated that OGI monitoring cannot rely 
on appendix K because that has not been finalized and the gasoline 
distribution rules must have a public comment period after the 
finalization of appendix K on which to evaluate its inclusion in the 
rules.
    Response: Appendix K was proposed prior to the proposal of the 
gasoline distribution technology and NSPS reviews, so it was available 
for comment. Commenters had both the opportunity to comment on appendix 
K by submitting comments to the Oil and Natural Gas Sector Climate 
review docket, Docket ID No. EPA-HQ-OAR-2021-0317, which it appears 
that the commenters did, and on our proposed use of appendix K in the 
gasoline distribution sector. Since commenters had the opportunity to 
comment on appendix K and on our proposed use of appendix K, we see no 
reason not to finalize the use of appendix K as proposed.
iv. What is the rationale for the EPA's final approach for the NSPS 
review?
    We are finalizing the equipment leak monitoring frequency for NSPS 
subpart XXa as quarterly monitoring because, as described in the June 
2022 proposal (87 FR 35627; June 10, 2022), we found this monitoring 
frequency cost-effective for VOC emission reductions at new, modified, 
and reconstructed affected facilities. We have also revised the 
affected facility definition, as described in section III.A.1.a.iv of 
this preamble, to separate the NSPS subpart XXa affected facility into 
a ``gasoline loading rack affected facility'' and a ``collection of 
equipment at a bulk gasoline terminal affected facility.''

B. Other Actions the EPA is Finalizing and the Rationale

1. SSM
    In its 2008 decision in Sierra Club v. EPA, 551 F.3d 1019 (D.C. 
Cir. 2008), the United States Court of Appeals for the District of 
Columbia Circuit (the court) vacated portions of two provisions in the 
EPA's CAA section 112 regulations governing the emissions of HAP during 
periods of SSM. Specifically, the court vacated the SSM exemption 
contained in 40 CFR 63.6(f)(1) and 40 CFR 63.6(h)(1), holding that 
under section 302(k) of the CAA, emissions standards or limitations 
must be continuous in nature and that the SSM exemption violates the 
CAA's requirement that some section 112 standards apply continuously. 
The EPA has determined the reasoning in the court's decision in Sierra 
Club applies equally to CAA section 111 because the definition of 
emission or standard in CAA section 302(k), and the embedded 
requirement for continuous standards, also applies to the NSPS.
    Periods of startup, normal operations, and shutdown are all 
predictable and routine aspects of a source's operations. Malfunctions, 
in contrast, are neither predictable nor routine. Instead, they are, by 
definition, sudden, infrequent, and not reasonably preventable failures 
of emissions control, process, or monitoring equipment (40 CFR 60.2 and 
63.2) (definition of malfunction). As explained in the June 10, 2022, 
proposal preamble (87 FR 35628), the EPA interprets CAA sections 111 
and 112 as not requiring emissions that occur during periods of 
malfunction to be factored into development of CAA sections 111 and 112 
standards.
a. Elimination of the SSM Exemption in NESHAP Subpart R
    The EPA proposed amendments to NESHAP subpart R to remove 
provisions related to SSM that are not consistent with the requirement 
that the standards apply at all times. More information concerning the 
elimination of SSM provisions is in the preamble to the proposed rule 
(87 FR 35628; June 10, 2022). The EPA is finalizing removal of the SSM 
provisions in NESHAP subpart R as proposed with the exception that we 
are including language that follows the language in 40 CFR 63.8(d)(3) 
in two paragraphs instead of just one as proposed and revising the 
language to align with the language more closely in 40 CFR 63.8(d)(3). 
The EPA had proposed to add language at 40 CFR 63.428(d)(4), as 
renumbered in the proposal, that followed the language in 40 CFR 
63.8(d)(3) with the last sentence replaced to eliminate reference to 
SSM plan. As described in section III.B.3.g.i of this preamble, the EPA 
is finalizing existing and new recordkeeping provisions for the loading 
rack provisions in 40 CFR 63.428(c) and (d), so the EPA is including 
this added language in both 40 CFR 63.428(c)(4) and (d)(4) in the final 
rule so that it applies to bulk gasoline terminals regardless of 
whether they are complying with the current or new loading rack 
provisions.
b. Revisions To Address SSM Provisions in NESHAP Subpart BBBBBB
    The EPA proposed amendments to NESHAP subpart BBBBBB to remove 
references to malfunction and revise certain entries to Table 4 to 
Subpart BBBBBB of Part 63--Applicability of General Provisions (table 4 
to subpart BBBBBB) that are not consistent with the requirement that 
the standards apply at all times. More information concerning the 
proposed amendments is available in the preamble to the proposed rule 
(87 FR 35630; June 10, 2022). The EPA is finalizing the amendments in 
NESHAP subpart BBBBBB as proposed with the exception that we are 
revising the language in 40 CFR 63.11094(m), which was proposed at 40 
CFR 63.11094(k), to align with the language more closely in 40 CFR 
63.8(d)(3).
c. Finalize NSPS Subpart XXa Without SSM Exemptions
    The EPA proposed standards in NSPS subpart XXa that apply at all 
times. The EPA is finalizing in 40 CFR part 60, subpart XXa, specific 
requirements at 40 CFR 60.500a(c) that override the 40 CFR part 60 
general provisions for SSM requirements. In finalizing the standards in 
this rule, the EPA has taken into account startup and shutdown periods 
and, for the reasons explained in the

[[Page 39334]]

preamble to the proposed rule (87 FR 35630; June 10, 2022), has not 
finalized alternate standards for those periods.
2. Electronic Reporting
    To increase the ease and efficiency of data submittal and data 
accessibility, the EPA is finalizing, as proposed, a requirement that 
owners and operators of bulk gasoline terminals subject to the new NSPS 
at 40 CFR part 60, subpart XXa, and gasoline distribution facilities 
subject to NESHAP at 40 CFR part 63, subparts R and BBBBBB, submit 
electronic copies of required performance test reports, performance 
evaluation reports, semiannual reports, and Notification of Compliance 
Status reports through the EPA's Central Data Exchange (CDX) using the 
Compliance and Emissions Data Reporting Interface (CEDRI). A 
description of the electronic data submission process is provided in 
the memorandum, Electronic Reporting Requirements for New Source 
Performance Standards (NSPS) and National Emission Standards for 
Hazardous Air Pollutants (NESHAP) Rules, available in the docket for 
this action. The final rules require that performance test results 
collected using test methods that are supported by the EPA's Electronic 
Reporting Tool (ERT) as listed on the ERT website \8\ at the time of 
the test be submitted in the format generated through the use of the 
ERT or an electronic file consistent with the xml schema on the ERT 
website and that other performance test results be submitted in 
portable document format (PDF) using the attachment module of the ERT. 
Similarly, performance evaluation results of CEMS measuring relative 
accuracy test audit pollutants that are supported by the ERT at the 
time of the test must be submitted in the format generated through the 
use of the ERT or an electronic file consistent with the xml schema on 
the ERT website, and other performance evaluation results must be 
submitted in PDF using the attachment module of the ERT. For semiannual 
reports under NSPS subpart XXa and semiannual compliance reports under 
NESHAP subparts R and BBBBBB, the final rules require that owners and 
operators use the appropriate spreadsheet template to submit 
information to CEDRI. The final version of the template for these 
reports will be located on the CEDRI website.\9\ The final rules 
require that Notification of Compliance Status reports be submitted as 
a PDF upload in CEDRI.
---------------------------------------------------------------------------

    \8\ <a href="https://www.epa.gov/electronic-reporting-air-emissions/electronic-reporting-tool-ert">https://www.epa.gov/electronic-reporting-air-emissions/electronic-reporting-tool-ert</a>.
    \9\ <a href="https://www.epa.gov/electronic-reporting-air-emissions/cedri">https://www.epa.gov/electronic-reporting-air-emissions/cedri</a>.
---------------------------------------------------------------------------

    Furthermore, the EPA is finalizing, as proposed, provisions in NSPS 
subpart XXa that allow owners and operators the ability to seek 
extensions for submitting electronic reports for circumstances beyond 
the control of the facility, i.e., for a possible outage in CDX or 
CEDRI or for a force majeure event, in the time just prior to a 
report's due date, as well as the process to assert such a claim. These 
extensions were not added specifically to NESHAP subparts R and BBBBBB 
because they are codified in 40 CFR part 63, subpart A, General 
Provisions, at 40 CFR 63.9(k).
3. Technical and Editorial Changes
a. Applicability Equations in NESHAP Subpart R
    The EPA proposed amendments to NESHAP subpart R to remove 
applicability equations in 40 CFR 63.420 and have applicability 
determined solely based on major source determination. The EPA proposed 
a 3-year period for the removal of the use of the applicability 
equations. The Agency also proposed to remove two related definitions 
for ``controlled loading rack'' and ``uncontrolled loading rack.'' The 
EPA received comment that the definitions of ``controlled loading 
rack'' and ``uncontrolled loading rack,'' should not be deleted until 
the applicability equations can no longer be used. The EPA reviewed the 
use of these terms in NESHAP subpart R and confirmed those terms are 
only used in the applicability equations. The EPA agrees with 
commenters that the definitions of ``controlled loading rack'' and 
``uncontrolled loading rack'' should remain in NESHAP subpart R to 
define the terms used in the applicability equations while they are 
still available for use. Therefore, the EPA is not finalizing the 
proposed deletion of the terms ``controlled loading rack'' and 
``uncontrolled loading rack'' from 40 CFR 63.421. Otherwise, we are 
finalizing the transition away from using the applicability equations 
as proposed.
b. Definitions of Bulk Gasoline Terminal, Pipeline Breakout Station, 
and Pipeline Pumping Station
    In NESHAP subparts R and BBBBBB, the EPA proposed to transition to 
new definitions of ``bulk gasoline terminal'' and ``pipeline breakout 
station'' over a 3-year period. We also proposed to revise the 
definition of ``pipeline pumping station'' in NESHAP subpart BBBBBB, 
effective on the effective date. The proposed revision to the 
definition of ``bulk gasoline terminal'' was minor, clarifying that the 
facility ``. . . subsequently loads all or a portion of the gasoline 
into gasoline cargo tanks for transport to bulk gasoline plants or 
gasoline dispensing facilities . . .'' We did not receive any comments 
on the proposed definition of ``bulk gasoline terminal,'' and we are 
finalizing the definition as proposed with the exception of the 
definition in NESHAP subpart BBBBBB. We are finalizing the definition 
of ``bulk gasoline terminal'' in NESHAP subpart BBBBBB to be consistent 
with the gasoline throughput requirements currently in the rule. The 
definition of ``bulk gasoline terminal'' in NESHAP subpart BBBBB is 
``any gasoline facility which . . . has a gasoline throughput of 20,000 
gallons per day (75,700 liter per day) or greater.'' The revisions to 
the definition of ``pipeline pumping station'' were proposed to clarify 
that pipeline pumping stations do not have gasoline loading racks. We 
did not receive any comments on the proposed definition of ``pipeline 
pumping station,'' and we are finalizing the definition as proposed.
    The proposed revisions to the ``pipeline breakout station'' 
definition added two sentences to clarify that facilities that have 
gasoline loading racks are to be considered bulk gasoline terminals 
rather than pipeline breakout stations. These two added sentences were: 
``Pipeline breakout stations do not have loading racks. If any gasoline 
is loaded into cargo tanks, the facility is a bulk gasoline terminal 
for the purposes of this subpart provided the facility-wide gasoline 
throughput (including pipeline throughput) exceeds the limits specified 
for bulk gasoline terminals.''
    Comment: A commenter stated that pipeline facilities may have 
loading racks, but these may not be used for gasoline loading (i.e., 
for diesel fuel loading or other materials) or rarely used for gasoline 
loading (e.g., used only when conducting maintenance on storage tanks). 
According to the commenter, these limited loading operations should not 
trigger the loading rack control requirements for bulk gasoline 
terminals. The commenter also indicated that the parenthetical phrase 
``including pipeline throughput'' is confusing and suggested that the 
throughput threshold consider only the ``gasoline loading design 
throughput.''
    Response: We agree that the first sentence added to the definition 
of ``pipeline breakout station'' was overly broad and should be revised 
to specify that the loading racks are for loading gasoline into cargo 
tanks. If only diesel fuel loading is conducted at the facility,

[[Page 39335]]

the facility should be considered a pipeline station. With respect to 
the parenthetical phrase ``. . . (including pipeline throughput) . . 
.,'' we intentionally included this phrase to require all pipeline 
breakout stations to use their total facility gasoline throughput so 
that facilities that have both pipeline breakout operations and co-
located gasoline loading operations would be considered bulk gasoline 
terminals. We note that the definition of bulk gasoline terminal also 
refers to the facility and does not limit the referenced throughput to 
just that of the loading operations. We consider the parenthetical 
helps to clarify the definition and is consistent with our 
interpretation that the 20,000 gallon per day throughput threshold 
within the definition of ``bulk gasoline terminal'' is a facility-level 
throughput and not limited to the throughput of only the gasoline 
loading racks. If all of the gasoline managed by the facility is not 
loaded into cargo tanks, as in the case of co-located pipeline breakout 
operations and gasoline loading operations, then the 20,000-gallon 
throughput threshold is to be evaluated based on the facility's total 
gasoline throughput and not just the throughput of the loading 
operations. For major sources of HAP emissions, this would require the 
loading operations to meet the 10 mg/L TOC limit in NESHAP subpart R. 
For area sources, the provisions for bulk gasoline terminals in NESHAP 
subpart BBBBBB have separate requirements based on the actual gasoline 
throughput of all loading racks at the facility. As such, area source 
facilities with co-located pipeline breakout operations and gasoline 
loading operations would be either subject to the proposed 35 mg/L TOC 
emission limit or the submerged fill requirements in NESHAP subpart 
BBBBBB based on the gasoline throughput of all loading racks.
    We note that if only the loading rack throughput was used as 
suggested by the commenter, some co-located loading operations could be 
considered bulk gasoline plants. For major sources subject to NESHAP 
subpart R, these loading operations would have no control requirements, 
not even a submerged fill requirement. For area sources, the loading 
operations would be considered subject to the vapor balancing 
requirements proposed for bulk gasoline plants in NESHAP subpart BBBBBB 
if the gasoline throughput is 4,000 gallons per day or more. Because 
storage tanks at pipeline breakout stations are large and predominately 
controlled using floating roofs, the proposed vapor balancing 
requirement would not be appropriate. We find that the 20,000-gallon 
per day threshold for bulk gasoline terminals is most appropriately 
determined based on the total gasoline throughput of the facility and 
that treating facilities that may have been previously considered a 
pipeline breakout station with gasoline loading operations as a bulk 
gasoline terminal in all cases provides a reasonable method to ensure 
all loading operations have an applicable requirement.
    After considering the comments received, we are finalizing the 
definitions of ``bulk gasoline terminal,'' ``pipeline breakout 
station,'' and ``pipeline pumping station'' as proposed with an 
additional clarification in the definition of ``pipeline breakout 
station'' through the addition of the underlined phrase: ``Pipeline 
breakout stations do not have loading racks where gasoline is loaded 
into cargo tanks.''
c. Definition of Gasoline
    We proposed a minor revision to the definition of ``gasoline'' in 
NESHAP subpart BBBBBB to include the Reid vapor pressure in units of 
pounds per square inch (in addition to kilopascals) because those are 
the units of measure commonly used in the U.S. gasoline distribution 
industry. We proposed to directly include this same definition of 
``gasoline'' in NESHAP subpart R, rather than rely on the definition of 
``gasoline'' in NSPS subpart XX or XXa. We received no comment on these 
proposed revisions related to the definition of ``gasoline'' and are 
finalizing the revised or added definition as proposed.
d. Definition of Submerged Filling
    Because we proposed to add submerged fill requirements in NESHAP 
subpart R, we also proposed to add a definition of ``submerged 
filling'' to NESHAP subpart R. The proposed definition of ``submerged 
filling'' was similar to the definition already included in NESHAP 
subpart BBBBBB. We received no comment on the proposed definition of 
``submerged filling'' and are finalizing the added definition as 
proposed with the exception that we are removing the phrase ``for the 
purposes of this subpart'' from NSPS subpart XXa and NESHAP subpart R.
e. Definition of Flare and Thermal Oxidation System
    We proposed a revision to the definitions of ``flare'' and 
``thermal oxidation system'' in NESHAP subpart R. We proposed to 
include these same definitions of ``flare'' and ``thermal oxidation 
system'' to NESHAP subpart BBBBBB. These proposed revisions were to 
clarify the distinction between control systems subject to performance 
testing as thermal oxidation systems because they emit pollutants 
through a conveyance suitable for performance testing and flares are 
exempt from performance testing because they do not emit pollutants 
through a conveyance suitable for performance testing.
    Comment: Several commenters requested that the EPA change the 
definition and phrasing in the rule from ``thermal oxidation system'' 
to ``vapor combustion unit'' because this is the term commonly used by 
the industry. One commenter noted that the use of ``thermal oxidation 
system'' is broadly inconsistent with the way gasoline vapor combustion 
units, flares, and thermal oxidation systems have been treated 
previously in these and other rules and how they are treated by States 
and in facility permits. One commenter recommended that in the 
definition of ``thermal oxidation system'' the EPA replace ``Auxiliary 
fuel may be used to heat air pollutants to combustion temperatures'' 
with ``Auxiliary fuel may be used to sustain combustion.'' One 
commenter recommended revising ``. . . device used to mix and ignite 
fuel, air pollutants, and air to provide a flame to heat and oxidize 
air pollutants . . .'' to more simply state ``device designed to mix 
air and vapors in direct contact with a flame to oxidize air 
pollutants'' because vapor combustion units commonly do not use 
auxiliary fuel and because effective combustion does not require 
heating.
    Response: These gasoline distribution rules have long used the term 
``thermal oxidation system.'' As such, facilities complying with these 
regulations must already be familiar with this term. We reviewed the 
revisions that would be needed to change this term to ``vapor 
combustion unit'' and were concerned by the possibility of missing all 
references to this term. However, during our review, we identified that 
we had not revised the phrase ``thermal oxidation system other than a 
flare'' in 40 CFR 63.427(a)(3) and 63.11092(b)(1)(iii) and (e)(1) and 
(2), an

[…truncated; see source link]
Indexed from Federal Register on May 8, 2024.

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