Document ID: EPA-HQ-OAR-2012-0522-0098
Agency: epa
Document Type: Rule
Title: Phosphoric Acid Manufacturing and Phosphate Fertilizer Production Risk and Technology Review Reconsideration
Posted Date: 2017-09-28T04:00Z

[Federal Register Volume 82, Number 187 (Thursday, September 28, 2017)]
[Rules and Regulations]
[Pages 45193-45202]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 2017-20171]

[[Page 45193]]

-----------------------------------------------------------------------

ENVIRONMENTAL PROTECTION AGENCY

40 CFR Part 63

[EPA-HQ-OAR-2012-0522; FRL-9968-01-OAR]
RIN 2060-AT14

Phosphoric Acid Manufacturing and Phosphate Fertilizer Production 
Risk and Technology Review Reconsideration

AGENCY: Environmental Protection Agency (EPA).

ACTION: Final rule; notification of final action on reconsideration.

-----------------------------------------------------------------------

SUMMARY: This action finalizes amendments to the National Emission 
Standards for Hazardous Air Pollutants (NESHAP) for the Phosphoric Acid 
Manufacturing and Phosphate Fertilizer Production source categories. 
These final amendments are in response to two petitions for 
reconsideration filed by industry stakeholders on the rule revisions to 
the NESHAP for the Phosphoric Acid Manufacturing and Phosphate 
Fertilizer Production source categories that were promulgated on August 
19, 2015. We are revising the compliance date by which affected sources 
must include emissions from oxidation reactors when determining 
compliance with the total fluoride emission limits for superphosphoric 
acid (SPA) process lines. In addition, we are revising the compliance 
date for the monitoring requirements for low-energy absorbers. We are 
also clarifying one option and adding a new option, to the monitoring 
requirements for low-energy absorbers.

DATES: This final rule is effective on September 28, 2017.

ADDRESSES: The Environmental Protection Agency (EPA) has established a 
docket for this action under Docket ID No. EPA-HQ-OAR-2012-0522. All 
documents in the docket are listed on the https://www.regulations.gov 
Web site. Although listed in the index, some information is not 
publicly available, e.g., confidential business information or other 
information whose disclosure is restricted by statute. Certain other 
material, such as copyrighted material, is not placed on the Internet 
and will be publicly available only in hard copy form. Publicly 
available docket materials are available either electronically through 
https://www.regulations.gov or in hard copy at the EPA Docket Center 
(EPA/DC), EPA WJC West Building, Room 3334, 1301 Constitution Ave. NW., 
Washington, DC. The Public Reading Room is open from 8:30 a.m. to 4:30 
p.m., Monday through Friday, excluding legal holidays. The telephone 
number for the Public Reading Room is (202) 566-1744, and the telephone 
number for the EPA Docket Center is (202) 566-1742.

FOR FURTHER INFORMATION CONTACT: Ms. Susan Fairchild, Sector Policies 
and Programs Division (Mail Code D243-02), Office of Air Quality 
Planning and Standards, Environmental Protection Agency, Research 
Triangle Park, North Carolina 27711; telephone number: (919) 541-5167; 
email address: fairchild.susan@epa.gov.

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

AMP Alternative monitoring plan
CAA Clean Air Act
CBI Confidential business information
CFR Code of Federal Regulations
EPA U.S. Environmental Protection Agency
FR Federal Register
MACT Maximum achievable control technology
NAICS North American Industry Classification System
NESHAP National emission standards for hazardous air pollutants
OMB Office of Management and Budget
PRA Paperwork Reduction Act
RTR Risk and technology review
SPA Superphosphoric acid
TAC Total annualized cost
TCI Total capital investment
TF Total fluoride
TFI The Fertilizer Institute
tpy Tons per year
UMRA Unfunded Mandates Reform Act

    Organization of this Document. The following outline is provided to 
aid in locating information in this preamble.

I. General Information
    A. Does this action apply to me?
    B. How do I obtain a copy of this document and other related 
information?
    C. Judicial Review
II. Background Information
III. Summary of Final Action on Issues Reconsidered
    A. Compliance Deadline for Air Oxidation Reactors Used in SPA 
Lines
    B. Compliance Deadlines for Revised Low-Energy Absorber 
Monitoring Provisions
    C. Monitoring Options for Low-Energy Absorbers
    D. Restoration of the 20-Percent Minimum Liquid Flow 
Rate Variability Allowance
IV. Impacts Associated With This Final Rule
V. Statutory and Executive Order Reviews
    A. Executive Order 12866: Regulatory Planning and Review and 
Executive Order 13563: Improving Regulation and Regulatory Review
    B. Paperwork Reduction Act (PRA)
    C. Regulatory Flexibility Act (RFA)
    D. Unfunded Mandates Reform Act (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
    K. Congressional Review Act (CRA)

I. General Information

A. Does this action apply to me?

    Categories and entities potentially affected by this 
reconsideration action include those listed in Table 1 of this 
preamble.

 Table 1--NESHAP and Industrial Source Categories Affected by This Final
                                 Action
------------------------------------------------------------------------
               NESHAP and source category                 NAICS \1\ code
------------------------------------------------------------------------
Phosphoric Acid Manufacturing..........................          325312
Phosphate Fertilizer Production
------------------------------------------------------------------------
\1\ North American Industry Classification System.

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

B. How do I obtain a copy of this document and other related 
information?

    The docket number for this final action regarding the NESHAP for 
the Phosphoric Acid Manufacturing and Phosphate Fertilizer Production 
source categories is Docket ID No. EPA-HQ-OAR-2012-0522.
    In addition to being available in the docket, an electronic copy of 
this document will also be available on the Internet. Following 
signature by the EPA Administrator, the EPA will post a

[[Page 45194]]

copy of this final action at https://www.epa.gov/stationary-sources-air-pollution/phosphate-fertilizer-production-plants-and-phosphoric-acid. Following publication in the Federal Register, the EPA will post 
the Federal Register version and key technical documents on this same 
Web site.

C. Judicial Review

    Under Clean Air Act (CAA) section 307(b)(1), judicial review of 
this final rule is available only by filing a petition for review in 
the U.S. Court of Appeals for the District of Columbia Circuit (the 
Court) by November 27, 2017. Under CAA section 307(d)(7)(B), only an 
objection to this final rule that was raised with reasonable 
specificity during the period for public comment can be raised during 
judicial review. Note, under CAA section 307(b)(2), the requirements 
established by this final rule may not be challenged separately in any 
civil or criminal proceedings brought by the EPA to enforce these 
requirements.

II. Background Information

    On June 10, 1999 (64 FR 31358), the EPA promulgated 40 CFR part 63, 
subpart AA for the Phosphoric Acid Manufacturing source category and 40 
CFR part 63, subpart BB for the Phosphate Fertilizer Production source 
category. On August 19, 2015 (80 FR 50386), the EPA published amended 
rules for both source categories that took into consideration the 
technology review and residual risk review required by sections 
112(d)(6) and 112(f) of the CAA, respectively. Following promulgation 
of the August 2015 rule revisions, the EPA received two petitions for 
reconsideration from The Fertilizer Institute (TFI) and the Phosphate 
Corporation of Saskatchewan, including: PCS Phosphate Company, Inc.; 
White Springs Agricultural Chemical, Inc., DBA PCS Phosphate-White 
Springs; and PCS Nitrogen Fertilizer, L.P., (collectively ``PCS''), 
requesting administrative reconsideration of amended 40 CFR part 63, 
subpart AA and subpart BB under CAA section 307(d)(7)(B).
    In response to the petitions, the EPA reconsidered and requested 
comment on three distinct issues:
     Compliance deadline for air oxidation reactors used in SPA 
lines;
     Compliance deadlines for low-energy absorber monitoring 
provisions; and
     Monitoring options for low-energy absorbers.
    The EPA proposed a notice of reconsideration including proposed 
rule amendments in the Federal Register on December 9, 2016 (81 FR 
89026). We received public comments from two parties. Copies of all 
comments submitted are available at the EPA Docket Center Public 
Reading Room. Comments are also available electronically through http://www.regulations.gov by searching Docket ID No. EPA-HQ-OAR-2012-0522.
    In this document, the EPA is taking final action with respect to 
the reconsideration and proposed amendments. Section III of this 
preamble summarizes the public comments received on the proposed notice 
of reconsideration, presents the EPA's responses to the comments, and 
explains our rationale for the rule revisions published here.
    We are also restoring a provision of the 1999 maximum achievable 
control technology (MACT) rules that was inadvertently omitted from the 
risk and technology review (RTR) amendments to those rules. That 
provision, related to compliance monitoring, allowed sources a 20-percent variability in the minimum liquid flow rate to the 
absorber.

III. Summary of Final Action on Issues Reconsidered

    The three reconsideration issues for which amendments are being 
finalized in this rulemaking are: (1) Compliance deadlines for air 
oxidation reactors used in SPA lines; (2) compliance deadlines for 
revised low-energy absorber monitoring provisions; and (3) monitoring 
options for low-energy absorbers. A fourth issue, which was identified 
after the close of the public comment period, is also being addressed 
in this action. This is the restoration of the 20-percent 
variability allowance for the minimum liquid flow rate to the absorber. 
Each of these issues is discussed in detail in the following sections 
of this preamble.

A. Compliance Deadline for Air Oxidation Reactors Used in SPA Lines

    In the August 19, 2015, amendments to 40 CFR part 63, subpart AA, 
the EPA revised the SPA process line definition to include oxidation 
reactors. The EPA received petitions requesting the compliance schedule 
be changed to allow more time for affected sources to include emissions 
from oxidation reactors when determining compliance with the total 
fluoride (TF) emission limits for SPA process lines. In response to the 
petitions, on December 9, 2016, we proposed to revise the compliance 
date from August 19, 2016, to August 19, 2018. We did not receive 
adverse comments on this change. Instead, both commenters stated that 
they supported this change. Therefore, in this action, the EPA is 
finalizing the compliance date revision as proposed. The compliance 
date by which affected sources must include emissions from oxidation 
reactors when determining compliance with the TF emission limits for 
SPA process lines is August 19, 2018.\1\
---------------------------------------------------------------------------

    \1\ Refer to finalized footnotes ``c'' of Table 1 and Table 2 to 
subpart AA of 40 CFR part 63.
---------------------------------------------------------------------------

B. Compliance Deadlines for Revised Low-Energy Absorber Monitoring 
Provisions

    In the August 19, 2015, amendments to 40 CFR part 63, subpart AA 
and 40 CFR part 63, subpart BB, the EPA changed the compliance 
monitoring requirement for low-energy absorbers (i.e., absorbers that 
are designed to operate with pressure drops of 5 inches of water column 
or less) to require monitoring of liquid-to-gas ratio in lieu of 
monitoring influent liquid flow and pressure drop through the absorber. 
The EPA received petitions requesting the compliance schedule be 
changed to allow more time for affected sources to comply with these 
monitoring requirements. In response to the petitions, on December 9, 
2016, we proposed to revise the compliance dates from August 19, 2016, 
to August 19, 2017, to allow owners and operators additional time to 
obtain and certify the instruments needed to monitor liquid-to-gas 
ratio. However, in this action, the EPA is revising the compliance 
dates to no later than August 19, 2018, for existing sources as well as 
for those sources that commenced construction or reconstruction after 
December 27, 1996, and on or before August 19, 2015. We are also 
clarifying that new sources that commence construction or 
reconstruction after August 19, 2015, must comply with the monitoring 
requirements for absorbers immediately upon startup.
    Both commenters said that the proposed compliance date (i.e., 
August 19, 2017) for monitoring liquid-to-gas ratio on low-energy 
absorbers only allows approximately seven months to achieve compliance 
from the date public comments were due (i.e., January 23, 2017). These 
commenters asserted that a duration of 7 months may not be sufficient 
to acquire, engineer, test, and install the requisite technologies. One 
of the commenters specified that 7 months is not enough time to 
complete and begin implementing gas flow monitoring plans for at least 
20 of their low-energy absorbers. Additionally, the commenter

[[Page 45195]]

asserted that for at least some of their low-energy absorbers, gas flow 
meters are likely not feasible due to the saturated (and sometimes 
supersaturated) conditions of the gas streams that these absorbers 
handle; therefore, the commenter contended they need more time to 
assess liquid-to-gas ratio monitoring options and to establish 
operating limits. The commenter stated that each liquid-to-gas ratio 
monitoring option requires complicated, time-consuming, and absorber-
specific evaluations. For example, to develop regression models, new 
instrumentation to monitor fan suction pressure and blower amperage 
must be installed for some absorbers, and facilities need to make 
changes to their computer programs. Moreover, the commenter stated that 
once a regression model is developed, they need additional time to 
establish the liquid-to-gas ratio operating limit by conducting a 
performance test. This commenter also maintained that for some of their 
low-energy absorbers they may need to use an Alternative Monitoring 
Plan (AMP) to comply with the liquid-to-gas ratio monitoring 
requirements and 7 months may not be enough time to get approval for 
the AMP. The commenter cited a specific example where the EPA Region is 
in the tenth month of reviewing one of the company's AMP requests. 
Additionally, one commenter suggested that the EPA revise the 
``existing source'' definition in 40 CFR part 63, subpart AA and 40 CFR 
part 63, subpart BB to extend the compliance date (for the liquid-to-
gas ratio monitoring requirements for low-energy absorbers) to those 
new sources that were in operation on the date the technology review 
and residual risk review were proposed.
    Based on these comments, we agree that more time beyond what we 
proposed is needed to achieve compliance with the liquid-to-gas ratio 
monitoring requirements for low-energy absorbers. To allow time to 
evaluate all monitoring options, obtain and certify instruments, 
establish operating limits, and, in certain cases, develop a regression 
model or AMP, the EPA is finalizing a compliance date that is no later 
than August 19, 2018.\2\ This extension provides a total of 3 years 
from promulgation (of the August 19, 2015, amendments to 40 CFR part 
63, subparts AA and BB) for sources to comply with the rule, and is the 
maximum compliance period allowed by the CAA. We also agree with the 
commenter that the compliance date should apply to certain new sources. 
This was an error in the December 9, 2016, proposal as we did not 
intend for the compliance date to apply to only existing sources. 
Therefore, in this action, the EPA is correcting this error at footnote 
b for Table 3 to subpart AA of 40 CFR part 63 and footnote b for Table 
3 to subpart BB of 40 CFR part 63 such that the compliance date for the 
liquid-to-gas ratio monitoring requirements for low-energy absorbers 
applies to both existing sources and those new sources that commenced 
construction or reconstruction after December 27, 1996, and on or 
before August 19, 2015. We are also clarifying that new sources that 
commence construction or reconstruction after August 19, 2015, must 
comply with the monitoring requirements for absorbers immediately upon 
startup. Instead of revising the ``existing source'' definition as 
requested by the commenter, we determined it will be clearer and more 
straightforward to make the corrections in these footnotes.
---------------------------------------------------------------------------

    \2\ Refer to finalized footnote b of Table 3 to subpart AA of 40 
CFR part 63 and Table 3 to subpart BB of 40 CFR part 63.
---------------------------------------------------------------------------

    Furthermore, one commenter requested that the EPA add more 
compliance options for low-energy absorbers in advance of the 
compliance date for the liquid-to-gas ratio monitoring requirements. 
The commenter asserted that footnote b for Table 3 to subpart AA of 40 
CFR part 63 and footnote b for Table 3 to subpart BB of 40 CFR part 63 
are too narrowly drafted because they do not allow facilities to use 
liquid-to-gas ratio monitoring or their current monitoring strategies, 
such as monitoring in accordance with an already approved AMP or an 
applicable monitoring provision of a permit issued under 40 CFR part 
70, in advance of the compliance date. This commenter suggested edits 
to footnote b for Table 3 to subpart AA of 40 CFR part 63 and footnote 
b for Table 3 to subpart BB of 40 CFR part 63 (see docket item EPA-HQ-
OAR-2012-0522-0097) to allow compliance with any one of the following: 
(i) The monitoring requirements in Table 3 for absorbers designed and 
operated with pressure drops of 5 inches of water column or less; (ii) 
the applicable monitoring provisions of a permit issued under 40 CFR 
part 70 or an Alternative Monitoring Plan approved pursuant to 40 CFR 
63.8(f); or (iii) the installation of continuous parameter monitoring 
systems (CPMS) for pressure at the gas stream inlet or outlet of the 
absorber, and monitoring pressure drop through the absorber. We agree 
with the commenter that facilities should be allowed to use liquid-to-
gas ratio monitoring or their current approved monitoring strategy (in 
lieu of monitoring pressure drop through the absorber), in advance of 
the compliance date for the liquid-to-gas ratio monitoring requirements 
for low-energy absorbers. Therefore, for the most part, we included the 
commenter's edits to footnote b for Table 3 to subpart AA of 40 CFR 
part 63 and footnote b for Table 3 to subpart BB of 40 CFR part 63 in 
the final rules. However, we added language to the commenter's edits to 
ensure that if an owner or operator were to use a part 70 monitoring 
provision, it would be a federally enforceable provision. We also split 
the option to use a part 70 monitoring provision and the option to use 
an AMP such that it is one or the other. The final rule allows an owner 
or operator to use liquid-to-gas ratio monitoring or their current 
approved monitoring strategy (in lieu of monitoring pressure drop 
through the absorber), in advance of the compliance date for the 
liquid-to-gas ratio monitoring requirements for low-energy absorbers.
    Finally, one commenter requested that the EPA include language in 
the final rules to authorize compliance with an AMP that is still under 
review by an EPA Regional office beyond the compliance date for the 
liquid-to-gas ratio monitoring requirements, provided the AMP request 
was submitted to the Region more than 30 days in advance of the 
compliance deadline. The commenter maintained that without this type of 
category-specific provision, owners or operators are not entitled 
(based on the existing provision at 40 CFR 63.8(f)(1)) to rely on AMPs 
in advance of the EPA's approval. The commenter stated that although 40 
CFR 63.8(f)(5)(i) calls for the Agency to respond to AMP requests 
within 30 days of receipt, the EPA sometimes needs more than 30 days to 
grant or deny such requests. The commenter asserted they are unable to 
predict or control the response time of the EPA; therefore, they should 
not be required to carry the risk and uncertainty of relying on an AMP 
that is still under EPA review after the compliance deadline. The 
commenter also stated that facility-specific extensions may not be 
available under CAA section 112(i)(3)(B), which authorizes a 1-year 
extension if ``necessary for the installation of controls.'' The 
commenter contended that liquid-to-gas monitoring may require new 
equipment for some low-energy absorbers, but the new equipment will 
likely be for absorber

[[Page 45196]]

monitoring and not control of pollutants.
    We disagree with the commenter's request to authorize compliance 
with AMPs that are still under the EPA review beyond the compliance 
date for the liquid-to-gas ratio monitoring requirements. As stated 
previously, we are revising and finalizing the compliance date for the 
liquid-to-gas ratio monitoring requirements for low-energy absorbers to 
no later than August 19, 2018, which is 3 years from promulgation of 
the final rule, and is the maximum allowed under the CAA for phosphoric 
acid and phosphate fertilizer manufacturers to comply with the rule. We 
believe this is an ample amount of time for any outstanding AMPs to be 
approved. Furthermore, the existing provision at 40 CFR 63.8(f)(1) has 
been in place for more than 20 years. During this time, the process for 
review and resolution of AMP requests has functioned satisfactorily 
within the established timelines. The concern raised by the commenter 
involves one unique case currently under consideration. We concluded 
that adopting a blanket exemption from the procedures of 40 CFR 63.8(f) 
for all owners or operators of the Phosphoric Acid Manufacturing and 
Phosphate Fertilizer Production source categories is inappropriate. 
This one unique case is more appropriately handled by the EPA Regional 
office continuing to review the technical merits of the AMP application 
and applying enforcement discretion to ensure equitable treatment of 
the company.

C. Monitoring Options for Low-Energy Absorbers

    In response to the petitions the EPA received regarding monitoring 
requirements for low-energy absorbers, we proposed to clarify an 
existing monitoring option (i.e., the blower design capacity option) 
and to add a new option (i.e., the regression model option) to 40 CFR 
part 63, subpart AA and 40 CFR part 63, subpart BB. We also proposed 
language reminding affected entities that they can request an 
alternative monitoring method under the provisions of 40 CFR 63.8(f) on 
a site-specific basis. Refer to the preamble to the proposed rule (81 
FR 89026) for more details on each of these changes.
    With exception of the items discussed in the following paragraphs, 
commenters stated that they supported these changes. Therefore, unless 
discussed below, we are finalizing the changes regarding monitoring 
requirements for low-energy absorbers as proposed.
Blower Design Capacity Option
    In response to petitioner requests for clarification of the 
regulatory language describing the blower design capacity option for 
determining the gas flow rate through the absorber (for use in 
monitoring the liquid-to-gas ratio), we clarified in the preamble to 
the proposed rulemaking how this option can be used. Additionally, we 
proposed changing the term ``design blower capacity'' in Table 3 to 
subpart AA of 40 CFR part 63 and Table 3 to subpart BB of 40 CFR part 
63 to ``blower design capacity'' and made other minor text edits to 
these tables in order to use the phrase ``gas flow rate through the 
absorber'' more consistently. We also proposed footnote c for Table 3 
to subpart AA of 40 CFR part 63 and footnote c for Table 3 to subpart 
BB of 40 CFR part 63 to add certain site-specific monitoring plan 
requirements, clarify that the blower design capacity option is 
intended to establish the maximum possible gas flow through the 
absorber, and explain that the blower design capacity option can be 
used regardless of whether the blower is located on the influent or 
effluent side of the absorber. Finally, we proposed a requirement at 40 
CFR 63.608(e) and 40 CFR 63.628(e) to document, in the site-specific 
monitoring plan, the calculations that were used to make adjustments 
for pressure drop if blower design capacity is used to establish the 
maximum possible gas flow rate through an absorber. In this action, the 
EPA is finalizing, with one exception, all the proposed language 
regarding the blower design capacity option.
    The one change to the proposed language for the blower design 
capacity option is our addition of language in footnote c to Table 3 to 
subpart AA of 40 CFR part 63 and Table 3 to subpart BB of 40 CFR part 
63 to clarify that owners and operators must establish the minimum 
liquid-to-gas ratio operating limit by dividing the minimum liquid flow 
rate to the absorber determined during a performance test by the 
maximum possible gas flow rate through the absorber determined using 
blower design capacity. One commenter requested the EPA include the 
following additional language to footnote c to Table 3 to subpart AA of 
40 CFR part 63 and Table 3 to subpart BB of 40 CFR part 63: ``The 
maximum design gas flow through the scrubber, or Fmax, shall be 
determined using the blower design capacity and system pressure drop. 
During performance testing, the observed liquid-to-gas ratio, L/G, will 
be determined. The minimum liquid flow will be established by 
multiplying the compliance L/G by Fmax.'' We disagree that the language 
should be added to footnote c as drafted by the commenter because it 
introduces a new undefined and unnecessary term ``Fmax.''
    We also disagree because much of the commenter's language is 
already included elsewhere in the rules,\3\ and while the commenter's 
suggested third sentence is not addressed elsewhere, it can be 
rewritten without the use of a new term, ``Fmax.'' Therefore, instead 
of using the commenter's suggested third sentence, we are including a 
new sentence in footnote c for Table 3 to subpart AA of 40 CFR part 63 
and footnote c for Table 3 to subpart BB of 40 CFR part 63 to read as 
follows: ``Establish the minimum liquid-to-gas ratio operating limit by 
dividing the minimum liquid flow rate to the absorber (determined 
during a performance test) by the maximum possible gas flow rate 
through the absorber (determined using blower design capacity).'' We 
consider this revised sentence as clarifying how each term in the 
liquid-to-gas ratio is determined and used.
---------------------------------------------------------------------------

    \3\ Existing rule language currently in the rules that the 
commenter suggested is found at Table 3 to subpart AA of 40 CFR part 
63; Table 3 to subpart BB of 40 CFR part 63; 40 CFR 63.605(d); at 40 
CFR 63.625(d); at Table 4 to subpart AA of 40 CFR part 63 and at 
Table 4 to subpart BB of 40 CFR part 63.
---------------------------------------------------------------------------

Regression Model Option
    In response to the petitions the EPA received requesting other 
options to be considered for determining the gas flow rate through the 
absorber, which is used in monitoring the liquid-to-gas ratio, we 
proposed to include an option in Table 3 to subpart AA of 40 CFR part 
63 and in Table 3 to subpart BB of 40 CFR part 63, that allows 
facilities to develop and use a regression model to determine gas flow 
rate through an absorber in lieu of direct measurement or using blower 
design capacity. We also proposed a requirement in footnote a for Table 
4 to subpart AA of 40 CFR part 63 and footnote a for Table 4 to subpart 
BB of 40 CFR part 63 requiring continuous monitoring of blower 
amperage, blower static pressure, i.e., fan suction pressure, and any 
other parameters used in the regression model that are not constants. 
Finally, to allow the flexibility to use best engineering judgment and 
calculations, we also proposed an annual requirement at 40 CFR 
63.608(f) and 40 CFR 63.628(f) to document, in the site-specific 
monitoring plan, the calculations that were used to develop the 
regression model and to require that the site-specific monitoring plan 
be updated annually to maintain accuracy

[[Page 45197]]

and reflect data used in the annual regression model verification.
    Both commenters stated that they support the use of a regression 
model to determine gas flow rate through an absorber, but requested one 
clarification to the proposed language. The commenters requested that 
the EPA revise footnote d for Table 3 to subpart AA of 40 CFR part 63 
and footnote d for Table 3 to subpart BB of 40 CFR part 63 to clarify 
whether an emissions performance test is necessary when developing and 
verifying gas flow regression models. The commenters contended that the 
EPA should allow facilities to develop and verify gas flow regression 
models separately from the required annual emissions performance test. 
One commenter maintained that requiring facilities to conduct a 
performance test to develop a regression model would waste resources 
and needlessly complicate the schedule for liquid-to-gas ratio 
monitoring. The commenter contended that facilities would have to 
conduct more than one performance test in a year's time to first 
develop a regression model and then set operating limits for liquid-to-
gas ratio. The commenters suggested edits to footnote d for Table 3 to 
subpart AA of 40 CFR part 63 and footnote d for Table 3 to subpart BB 
of 40 CFR part 63 (see docket items EPA-HQ-OAR-2012-0522-0097 and EPA-
HQ-OAR-2012-0522-0098) to make clear that an emissions performance test 
is not required to develop and verify gas flow regression models. We 
agree with the commenters' edits to footnote d as it was our intent to 
allow facilities the flexibility to develop and verify gas flow 
regression models (using direct measurements of gas flow rate, for 
example, via EPA Method 2) either separately from, or in conjunction 
with, the annual performance test. Therefore, in this action, the EPA 
is finalizing, with one change, all the proposed language regarding the 
regression model option. The one change we are making to the proposed 
language is that we are revising and clarifying footnote d for Table 3 
to subpart AA of 40 CFR part 63 and footnote d for Table 3 to subpart 
BB of 40 CFR part 63 to convey that direct measurements of gas flow 
rate used to develop or verify regression models may be collected 
during, or separately from, the annual performance testing that is 
required in 40 CFR 63.606(b) for subpart AA or 40 CFR 63.626(b) for 
subpart BB.

D. Restoration of the 20-Percent Minimum Liquid Flow Rate 
Variability Allowance

    The June 10, 1999, MACT rules (64 FR 31358) included provisions to 
account for the variability in absorber (i.e., scrubber) pressure drop 
and the variability in minimum liquid flow rate to the absorber. 
Specifically, as a compliance monitoring provision of the 1999 MACT 
rules, owners/operators are required to conduct a performance test to 
determine the baseline average value for both the pressure drop and for 
the minimum liquid flow rate of the absorber, and are then allowed to 
operate within a range that is within 20 percent of this rate.
    The August 19, 2015 (80 FR 50386), RTR final rule included the 
allowance for the 20-percent variability in the absorber 
pressure drop, but did not include the allowance for the 20-percent variability in the minimum liquid flow rate to the 
absorber.
    Industry brought this omission to our attention after the comment 
period for this reconsideration rule. We subsequently reviewed the 
record for the August 2015 RTR final rule and could not find any record 
of a decision to remove the 20-percent minimum liquid flow 
rate variability provision. Therefore, we have concluded that this 
omission was an inadvertent error in the August 2015 RTR final rule, 
and we are restoring that provision in these final rules. Subpart AA 
includes this restored provision at 40 CFR 63.605(d)(1)(ii)(A) and 
subpart BB includes this restored provision at 40 CFR 
63.625(d)(1)(ii)(A).

IV. Impacts Associated With This Final Rule

    This action revises compliance dates specific to oxidation reactors 
in the Phosphoric Acid Manufacturing source category, and absorber 
monitoring in both the Phosphoric Acid Manufacturing and Phosphate 
Fertilizer Production source categories. We expect the additional 
compliance time for oxidation reactors to comply with the rule will 
have an insignificant effect on a phosphoric acid manufacturing plant's 
overall emissions.
    Specifically, in the reconsideration proposal, the EPA discussed 
hydrogen fluoride emissions reductions of 0.047 tons per year (tpy) 
from the oxidation reactor (i.e., a reduction from 0.049 tpy to 0.002 
tpy) and TF emissions reductions of 0.14 tpy from the oxidation reactor 
(i.e., a reduction from 0.147 tpy to 0.007 tpy). The additional 2-year 
compliance time for oxidation reactors to meet the emission limits in 
the final rule result in an additional 0.098 tons (196 pounds) of 
hydrogen fluoride and 0.28 tons (560 pounds) of total fluoride. 
Hydrogen fluoride emissions from SPA process lines, including oxidation 
reactors, account for less than 1 percent of all hydrogen fluoride 
emissions from the source category.
    The revisions related to the gas flow calculation that we are 
finalizing result in capital cost savings of $88,200 per facility, and 
capital cost savings of $1,147,200 industry-wide.\4\ These cost savings 
are due to our providing alternatives to the requirement to use a gas 
flow meter for monitoring gas flow at low energy absorbers. In addition 
to the gas flow meter, we are providing two other monitoring methods as 
alternative compliance options: (1) A blower design capacity model; and 
(2) a regression model.
---------------------------------------------------------------------------

    \4\ For the detailed calculations on these cost savings, refer 
to ``Detailed Costs of Monitoring Gas Flow Options Worksheet June 
2017.xlsx'' and ``Annualized Cost of Monitoring Options 
Worksheet.xlsx'' which are available in the docket for this rule.

                          Table 2--Cost Comparison of Different Options for Determining Gas Flow Rate at Low Pressure Absorbers
--------------------------------------------------------------------------------------------------------------------------------------------------------
                                                                            Annualized facility costs                     Annualized industry wide costs
                                                         Capital costs               (2016$)              Industry Wide               (2016$)
                   Compliance option                      per facility  --------------------------------  Capital Costs  -------------------------------
                                                                               3%              7%              \1\              3%              7%
--------------------------------------------------------------------------------------------------------------------------------------------------------
Blower Design Capacity Model..........................           $6,400            $800            $960          $83,700         $10,300         $12,500
Regression Model......................................            4,200             500             600           54,300           6,700           8,100
Gas Flow Meter........................................           92,400          15,800          18,200        1,201,500         205,900         236,100
--------------------------------------------------------------------------------------------------------------------------------------------------------
\1\ Capital costs per facility are rounded values. Industry-wide capital costs are calculated by multiplying the non-rounded values for capital costs
  per facility by 13 (the total number of facilities in the source category). The resulting product is rounded after calculation.

[[Page 45198]]

    The costs described in this action are a result of only the final 
reconsideration notice, and show a cost savings. The costs were 
calculated at both a 7-percent rate and a 3-percent rate. There is a 
reduction in estimated annualized costs calculated at both the 7-
percent rate and at the 3-percent rate as a result of all 13 affected 
facilities implementing a lower cost option to monitor the ratio of 
liquid-to-gas in low energy absorbers, as compared to the cost of that 
requirement in the rule promulgated in August 2015. We note that the 
cost savings presented here are not associated with any change in 
emission limit, do not result in higher hazardous air pollutant 
emissions, and do not have a negative effect on human health or the 
environment.

 Table 3--Total Potential Capital and Annualized Savings From Monitoring
                   Alternatives for Subparts AA and BB
                                 [2016$]
------------------------------------------------------------------------
      Total capital cost savings       Total annual cost savings (2016$)
------------------------------------------------------------------------
$1,147,000...........................  $208,000 (3% discount rate).
                                       $237,000 (7% discount rate).
------------------------------------------------------------------------

V. Statutory and Executive Order Reviews

    Additional information about these statutes and Executive Orders 
can be found at http://www2.epa.gov/laws-regulations/laws-anld-executive-orders.

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

    This action is not a significant regulatory action and was, 
therefore, not submitted to the Office of Management and Budget (OMB) 
for review.

B. Paperwork Reduction Act (PRA)

    This action does not impose any new information collection burden 
under the PRA. OMB has previously approved the information collection 
activities contained in the existing regulations and has assigned OMB 
control number 2060-0361. With this action, the EPA is finalizing 
amendments to 40 CFR part 63, subpart AA and 40 CFR part 63, subpart BB 
that are mainly clarifications to existing rule language to aid in 
implementation issues raised by stakeholders, or are being made to 
allow more time for compliance. Therefore, there are no changes to the 
information collection requirements of the August 19, 2015, final rule, 
and, consequently, the information collection estimate of projected 
costs and hour burden from the final rules have not been revised.

C. Regulatory Flexibility Act (RFA)

    I certify that this action will not have a significant economic 
impact on a substantial number of small entities under the RFA. This 
action will not impose any requirements on small entities. This action 
finalizes amendments to the 40 CFR part 63, subpart AA and 40 CFR part 
63, subpart BB that are mainly clarifications to existing rule language 
to aid in implementation issues raised by stakeholders, or are being 
made to allow more time for compliance.

D. Unfunded Mandates Reform Act (UMRA)

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

E. Executive Order 13132: Federalism

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

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

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

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

    This action is not subject to Executive Order 13045 because it is 
not economically significant as defined in Executive Order 12866, and 
because the EPA does not believe the environmental health or safety 
risks addressed by this action present a disproportionate risk to 
children. This action finalizes amendments to 40 CFR part 63, subpart 
AA and 40 CFR part 63, subpart BB that are mainly clarifications to 
existing rule language to aid in implementation issues raised by 
stakeholders, or are being made to allow more time for compliance. We 
expect the additional compliance time for oxidation reactors will have 
an insignificant effect on a phosphoric acid manufacturing plant's 
overall emissions. Hydrogen fluoride emissions from SPA process lines, 
including oxidation reactors, account for less than 1 percent of all 
hydrogen fluoride emissions from the source category. Therefore, the 
amendments should not appreciably increase risk for any populations.

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

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

I. National Technology Transfer and Advancement Act (NTTAA)

    This rulemaking does not involve new technical standards.

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

    The EPA believes that this action does not have disproportionately 
high and adverse human health or environmental effects on minority 
populations, low-income populations, and/or indigenous peoples, as 
specified in Executive Order 12898 (59 FR 7629, February 16, 1994). The 
Environmental Justice finding in the August 19, 2015, final rule 
remains relevant in this action, which finalizes amendments to these 
rules that are mainly clarifications to existing rule language to aid 
in implementation issues raised by stakeholders, or are being made to 
allow more time for compliance. We expect the additional compliance 
time for oxidation reactors will have an insignificant effect on any 
phosphoric acid manufacturing plant's overall emissions. Hydrogen 
fluoride emissions from SPA process lines, including oxidation 
reactors, account for less than 1 percent of all hydrogen fluoride 
emissions from the source category. Therefore, the amendments should 
not appreciably increase the risk for any populations.

K. Congressional Review Act (CRA)

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

[[Page 45199]]

List of Subjects in 40 CFR Part 63

    Environmental protection, Administrative practice and procedure, 
Air pollution control, Hazardous substances, Reporting and 
recordkeeping requirements.

    Dated: September 13, 2017.
E. Scott Pruitt,
Administrator.

    For the reasons stated in the preamble, part 63 of title 40, 
chapter I, of the Code of Federal Regulations is amended as follows:

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

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

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

Subpart AA--National Emission Standards for Hazardous Air 
Pollutants From Phosphoric Acid Manufacturing Plants

0
2. Section 63.605(d)(1)(ii)(A) is revised to read as follows:

Sec.  63.605  Operating and monitoring requirements.

* * * * *
    (d) * * *
    (1) * * *
    (ii) * * *
    (A) The allowable range for the daily averages of the pressure drop 
across an absorber and of the flow rate of the absorber liquid to each 
absorber in the process absorbing system, or secondary voltage for a 
wet electrostatic precipitator, is 20 percent of the 
baseline average value determined in paragraph (d)(1)(i) of this 
section. The Administrator retains the right to reduce the 20 percent adjustment to the baseline average values of operating 
ranges in those instances where performance test results indicate that 
a source's level of emissions is near the value of an applicable 
emissions standard. However, the adjustment must not be reduced to less 
than 10 percent under any instance.
* * * * *

0
3. Section 63.608 is amended by adding paragraphs (e) and (f) to read 
as follows:

Sec.  63.608  General requirements and applicability of general 
provisions of this part.

* * * * *
    (e) If you use blower design capacity to determine the gas flow 
rate through the absorber for use in the liquid-to-gas ratio as 
specified in Table 3 to this subpart, then you must include in the 
site-specific monitoring plan specified in paragraph (c) of this 
section calculations showing how you determined the maximum possible 
gas flow rate through the absorber based on the blower's specifications 
(including any adjustments you made for pressure drop).
    (f) If you use a regression model to determine the gas flow rate 
through the absorber for use in the liquid-to-gas ratio as specified in 
Table 3 to this subpart, then you must include in the site-specific 
monitoring plan specified in paragraph (c) of this section the 
calculations that were used to develop the regression model, including 
the calculations you use to convert amperage of the blower to brake 
horsepower. You must describe any constants included in the equations 
(e.g., efficiency, power factor), and describe how these constants were 
determined. If you want to change a constant in your calculation, then 
you must conduct a regression model verification to confirm the new 
value of the constant. In addition, the site-specific monitoring plan 
must be updated annually to reflect the data used in the annual 
regression model verification that is described in Table 3 to this 
subpart.

Table 1 to Subpart AA of Part 63 [Amended]

0
4. Table 1 to Subpart AA of Part 63, footnote ``c'' is amended by 
removing the text ``August 19, 2016,'' and adding the text ``August 19, 
2018,'' in its place.

Table 2 to Subpart AA of Part 63 [Amended]

0
5. Table 2 to Subpart AA of Part 63, footnote ``c'' is amended by 
removing the text ``August 19, 2016,'' and adding the text ``August 19, 
2018,'' in its place.

0
6. Table 3 to subpart AA of part 63 is amended by:
0
a. Revising the column headings for ``And you must monitor . . .'' and 
``And . . .'';
0
b. Revising the entry for ``Install CPMS for liquid and gas flow at the 
inlet of the absorber''; and
0
c. Adding footnotes ``a'' through ``d'' at the end of the table.
    The revisions and additions read as follows:

                   Table 3 to Subpart AA of Part 63--Monitoring Equipment Operating Parameters
----------------------------------------------------------------------------------------------------------------
                                                                 And you must monitor .
            You must . . .                     If . . .                 . . \a\               And . . . \a\
----------------------------------------------------------------------------------------------------------------
 
                                                  * * * * * * *
Install CPMS for liquid and gas flow   Your absorber is         Liquid-to-gas ratio as   You must determine the
 at the inlet of the absorber \b\.      designed and operated    determined by dividing   gas flow rate through
                                        with pressure drops of   the influent liquid      the absorber by:
                                        5 inches of water        flow rate by the gas    Measuring the gas flow
                                        column or less; or.      flow rate through the    rate at the absorber
                                       Your absorber is          absorber. The units of   inlet or outlet;
                                        designed and operated    measure must be         Using the blower design
                                        with pressure drops of   consistent with those    capacity, with
                                        5 inches of water        used to calculate this   appropriate
                                        column or more, and      ratio during the         adjustments for
                                        you choose to monitor    performance test.        pressure drop; \c\ or
                                        the liquid-to-gas                                Using a regression
                                        ratio, rather than                                model.\d\
                                        only the influent
                                        liquid flow, and you
                                        want the ability to
                                        lower liquid flow with
                                        changes in gas flow.
 
                                                  * * * * * * *
----------------------------------------------------------------------------------------------------------------
\a\ To monitor an operating parameter that is not specified in this table (including process-specific techniques
  not specified in this table to determine gas flow rate through an absorber), you must request, on a site-
  specific basis, an alternative monitoring method under the provisions of 40 CFR 63.8(f).

[[Page 45200]]

 
\b\ For new sources that commence construction or reconstruction after August 19, 2015, the compliance date is
  immediately upon startup. For existing sources, and new sources that commence construction or reconstruction
  after December 27, 1996, and on or before August 19, 2015, if your absorber is designed and operated with
  pressure drops of 5 inches of water column or less, then the compliance date is August 19, 2018. In the
  interim, for existing sources, and new sources that commence construction or reconstruction after December 27,
  1996, and on or before August 19, 2015, with an absorber designed and operated with pressure drops of 5 inches
  of water column or less, you must comply with one of the following: (i) The monitoring requirements in this
  Table 3 for absorbers designed and operated with pressure drops of 5 inches of water column or less; (ii) the
  applicable monitoring provisions included in a permit issued under 40 CFR part 70 to assure compliance with
  subpart AA; (iii) the applicable monitoring provisions of an Alternative Monitoring Plan approved pursuant to
  Sec.   63.8(f); or (iv) install CPMS for pressure at the gas stream inlet and outlet of the absorber, and
  monitor pressure drop through the absorber.
\c\ If you select this option, then you must comply with Sec.   63.608(e). The option to use blower design
  capacity is intended to establish the maximum possible gas flow through the absorber; and is available
  regardless of the location of the blower (influent or effluent), as long as the gas flow rate through the
  absorber can be established. Establish the minimum liquid-to-gas ratio operating limit by dividing the minimum
  liquid flow rate to the absorber (determined during a performance test) by the maximum possible gas flow rate
  through the absorber (determined using blower design capacity).
\d\ If you select this option, then you must comply with Sec.   63.608(f). The regression model must be
  developed using direct measurements of gas flow rate, and design fan curves that correlate gas flow rate to
  static pressure (i.e., fan suction pressure) and brake horsepower of the blower. You must conduct an annual
  regression model verification using direct measurements of gas flow rate to ensure the correlation remains
  accurate. Direct measurements of gas flow rate used to develop or verify regression models may be collected
  during, or separately from, the annual performance testing that is required in Sec.   63.606(b).

0
7. Table 4 to subpart AA of part 63 is amended by revising the entry 
for ``Influent liquid flow rate and gas stream flow rate'' and adding 
footnote ``a'' at the end of the table to read as follows:

         Table 4 to Subpart AA of Part 63--Operating Parameters, Operating Limits and Data Monitoring, Recordkeeping and Compliance Frequencies
--------------------------------------------------------------------------------------------------------------------------------------------------------
                                                                And you must monitor, record, and demonstrate continuous compliance using these minimum
   For the operating parameter       You must establish the                                        frequencies . . .
 applicable to you, as specified   following operating limit -------------------------------------------------------------------------------------------
         in Table 3 . . .                    . . .                                                                           Data averaging  period for
                                                                     Data measurement               Data  recording                  compliance
--------------------------------------------------------------------------------------------------------------------------------------------------------
 
                                                                      * * * * * * *
Influent liquid flow rate and gas  Minimum influent liquid-   Continuous...................  Every 15 minutes.............  Daily.
 stream flow rate.                  to-gas ratio \a\.
 
                                                                      * * * * * * *
--------------------------------------------------------------------------------------------------------------------------------------------------------
\a\ If you select the regression model option to monitor influent liquid-to-gas ratio as described in Table 3 to this subpart, then you must also
  continuously monitor (i.e., record every 15 minutes, and use a daily averaging period) blower amperage, blower static pressure (i.e., fan suction
  pressure), and any other parameters used in the regression model that are not constants.

Subpart BB--National Emission Standards for Hazardous Air 
Pollutants From Phosphate Fertilizers Production Plants

0
8. Section 63.625(d)(1)(ii)(A) is revised to read as follows:

Sec.  63.625  Operating and monitoring requirements.

* * * * *
    (d) * * *
    (1) * * *
    (ii) * * *
    (A) The allowable range for the daily averages of the pressure drop 
across an absorber and of the flow rate of the absorber liquid to each 
absorber in the process absorbing system, or secondary voltage for a 
wet electrostatic precipitator, is 20 percent of the 
baseline average value determined in paragraph (d)(1)(i) of this 
section. The Administrator retains the right to reduce the 20 percent adjustment to the baseline average values of operating 
ranges in those instances where performance test results indicate that 
a source's level of emissions is near the value of an applicable 
emissions standard. However, the adjustment must not be reduced to less 
than 10 percent under any instance.
* * * * *

0
9. Section 63.628 is amended by adding paragraphs (e) and (f) to read 
as follows:

Sec.  63.628  General requirements and applicability of general 
provisions of this part.

* * * * *
    (e) If you use blower design capacity to determine the gas flow 
rate through the absorber for use in the liquid-to-gas ratio as 
specified in Table 3 to this subpart, then you must include in the 
site-specific monitoring plan specified in paragraph (c) of this 
section calculations showing how you determined the maximum possible 
gas flow rate through the absorber based on the blower's specifications 
(including any adjustments you made for pressure drop).
    (f) If you use a regression model to determine the gas flow rate 
through the absorber for use in the liquid-to-gas ratio as specified in 
Table 3 to this subpart, then you must include in the site-specific 
monitoring plan specified in paragraph (c) of this section the 
calculations that were used to develop the regression model, including 
the calculations you use to convert amperage of the blower to brake 
horsepower. You must describe any constants included in the equations 
(e.g., efficiency, power factor), and describe how these constants were 
determined. If you want to change a constant in your calculation, then 
you must conduct a regression model verification to confirm the new 
value of the constant. In addition, the site-specific monitoring plan 
must be updated annually to reflect the data used in the annual 
regression model verification that is described in Table 3 to this 
subpart.

0
10. Table 3 to subpart BB of part 63 is amended by:
0
a. Revising the column headings for ``And you must monitor . . .'' and 
``And . . .'';

[[Page 45201]]

0
b. Revising the entry for ``Install CPMS for liquid and gas flow at the 
inlet of the absorber''; and
0
c. Adding footnotes ``a'' through ``d'' at the end of the table.
    The revisions and additions read as follows:

                   Table 3 to Subpart BB of Part 63--Monitoring Equipment Operating Parameters
----------------------------------------------------------------------------------------------------------------
                                                                 And you must monitor .
            You must . . .                     If . . .                 . . \a\               And . . . \a\
----------------------------------------------------------------------------------------------------------------
 
                                                  * * * * * * *
Install CPMS for liquid and gas flow   Your absorber is         Liquid-to-gas ratio as   You must determine the
 at the inlet of the absorber \b\.      designed and operated    determined by dividing   gas flow rate through
                                        with pressure drops of   the influent liquid      the absorber by:
                                        5 inches of water        flow rate by the gas    Measuring the gas flow
                                        column or less; or.      flow rate through the    rate at the absorber
                                       Your absorber is          absorber. The units of   inlet or outlet;
                                        designed and operated    measure must be         Using the blower design
                                        with pressure drops of   consistent with those    capacity, with
                                        5 inches of water        used to calculate this   appropriate
                                        column or more, and      ratio during the         adjustments for
                                        you choose to monitor    performance test.        pressure drop; \c\ or
                                        the liquid-to-gas                                Using a regression
                                        ratio, rather than                                model.\d\
                                        only the influent
                                        liquid flow, and you
                                        want the ability to
                                        lower liquid flow with
                                        changes in gas flow.
 
                                                  * * * * * * *
----------------------------------------------------------------------------------------------------------------
\a\ To monitor an operating parameter that is not specified in this table (including process-specific techniques
  not specified in this table to determine gas flow rate through an absorber), you must request, on a site-
  specific basis, an alternative monitoring method under the provisions of Sec.   63.8(f).
\b\ For new sources that commence construction or reconstruction after August 19, 2015, the compliance date is
  immediately upon startup. For existing sources, and new sources that commence construction or reconstruction
  after December 27, 1996, and on or before August 19, 2015, if your absorber is designed and operated with
  pressure drops of 5 inches of water column or less, then the compliance date is August 19, 2018. In the
  interim, for existing sources, and new sources that commence construction or reconstruction after December 27,
  1996, and on or before August 19, 2015, with an absorber designed and operated with pressure drops of 5 inches
  of water column or less, you must comply with one of the following: (i) The monitoring requirements in this
  Table 3 for absorbers designed and operated with pressure drops of 5 inches of water column or less; (ii) the
  applicable monitoring provisions included in a permit issued under 40 CFR part 70 to assure compliance with
  subpart BB; (iii) the applicable monitoring provisions of an Alternative Monitoring Plan approved pursuant to
  Sec.   63.8(f); or (iv) install CPMS for pressure at the gas stream inlet and outlet of the absorber, and
  monitor pressure drop through the absorber.
\c\ If you select this option, then you must comply with Sec.   63.628(e). The option to use blower design
  capacity is intended to establish the maximum possible gas flow through the absorber; and is available
  regardless of the location of the blower (influent or effluent), as long as the gas flow rate through the
  absorber can be established. Establish the minimum liquid-to-gas ratio operating limit by dividing the minimum
  liquid flow rate to the absorber (determined during a performance test) by the maximum possible gas flow rate
  through the absorber (determined using blower design capacity).
\d\ If you select this option, then you must comply with Sec.   63.628(f). The regression model must be
  developed using direct measurements of gas flow rate, and design fan curves that correlate gas flow rate to
  static pressure (i.e., fan suction pressure) and brake horsepower of the blower. You must conduct an annual
  regression model verification using direct measurements of gas flow rate to ensure the correlation remains
  accurate. Direct measurements of gas flow rate used to develop or verify regression models may be collected
  during, or separately from, the annual performance testing that is required in Sec.   63.626(b).

0
11. Table 4 to subpart BB of part 63 is revised to read as follows:

         Table 4 to Subpart BB of Part 63--Operating Parameters, Operating Limits and Data Monitoring, Recordkeeping and Compliance Frequencies
--------------------------------------------------------------------------------------------------------------------------------------------------------
                                                                And you must monitor, record, and demonstrate continuous compliance using these minimum
   For the operating parameter       You must establish the                                        frequencies . . .
 applicable to you, as specified   following operating limit -------------------------------------------------------------------------------------------
         in Table 3 . . .           during your performance                                                                  Data averaging  period for
                                           test . . .                Data measurement                Data recording                  compliance
--------------------------------------------------------------------------------------------------------------------------------------------------------
                                                                Absorbers (Wet Scrubbers)
--------------------------------------------------------------------------------------------------------------------------------------------------------
Influent liquid flow.............  Minimum inlet liquid flow  Continuous...................  Every 15 minutes.............  Daily.
Influent liquid flow rate and gas  Minimum influent liquid-   Continuous...................  Every 15 minutes.............  Daily.
 stream flow rate.                  to-gas ratio \a\.
                                                             -------------------------------------------------------------------------------------------
For the operating parameter        You must establish the       And you must monitor, record, and demonstrate continuous compliance using these minimum
 applicable to you, as specified    following operating                                            frequencies . . .
 in Table 3.                        limit.
                                                             -------------------------------------------------------------------------------------------
                                                              Data measurement.............  Data recording...............  Data averaging
                                                                                                                            period for
                                                                                                                            compliance.
Pressure drop....................  Pressure drop range......  Continuous...................  Every 15 minutes.............  Daily.
--------------------------------------------------------------------------------------------------------------------------------------------------------
                                                                    Sorbent Injection
--------------------------------------------------------------------------------------------------------------------------------------------------------
Sorbent injection rate...........  Minimum injection rate...  Continuous...................  Every 15 minutes.............  Daily.

[[Page 45202]]

 
Sorbent injection carrier gas      Minimum carrier gas flow   Continuous...................  Every 15 minutes.............  Daily.
 flow rate.                         rate.
--------------------------------------------------------------------------------------------------------------------------------------------------------
                                                                     Fabric Filters
--------------------------------------------------------------------------------------------------------------------------------------------------------
Alarm time.......................  Maximum alarm time is not  Continuous...................  Each date and time of alarm    Maximum alarm time specified
                                    established on a site-                                    start and stop.                in Sec.   63.605(f)(9).
                                    specific basis but is
                                    specified in Sec.
                                    63.605(f)(9).
--------------------------------------------------------------------------------------------------------------------------------------------------------
                                                             Wet Electrostatic Precipitator
--------------------------------------------------------------------------------------------------------------------------------------------------------
Secondary voltage................  Secondary voltage range..  Continuous...................  Every 15 minutes.............  Daily.
--------------------------------------------------------------------------------------------------------------------------------------------------------

[FR Doc. 2017-20171 Filed 9-27-17; 8:45 am]
BILLING CODE 6560-50-P