Document ID: EPA-HQ-OAR-2020-0016-0001
Agency: epa
Document Type: Proposed Rule
Title: National Emission Standards for Hazardous Air Pollutants: Phosphoric Acid Manufacturing
Posted Date: 2020-04-07T04:00Z

[Federal Register Volume 85, Number 67 (Tuesday, April 7, 2020)]
[Proposed Rules]
[Pages 19412-19418]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 2020-06930]

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ENVIRONMENTAL PROTECTION AGENCY

40 CFR Part 63

[EPA-HQ-OAR-2020-0016; FRL-10007-29-OAR]
RIN 2060-AU25

National Emission Standards for Hazardous Air Pollutants: 
Phosphoric Acid Manufacturing

AGENCY: Environmental Protection Agency (EPA).

ACTION: Proposed rule.

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SUMMARY: This action proposes to amend the National Emission Standards 
for Hazardous Air Pollutants (NESHAP) for the Phosphoric Acid 
Manufacturing source category. The proposed amendment is in response to 
a petition for rulemaking by an industry stakeholder on the mercury 
emission limit based on the maximum achievable control technology 
(MACT) floor for existing sources set in a rule that was finalized on 
August 19, 2015 (``2015 Rule''). All six of the existing calciners used 
to set this MACT floor were located at the PCS Phosphate Company, Inc. 
(``PCS Phosphate'') facility in Aurora, North Carolina (``PCS 
Aurora''). PCS Phosphate asserted that data received since the rule's 
promulgation indicate that the MACT floor did not accurately 
characterize the average emission limitation achieved by the units used 
to set the standard. Based on these new data, the U.S. Environmental 
Protection Agency (EPA) proposes to revise the mercury MACT floor for 
existing calciners.

DATES: 
    Comments. Comments must be received on or before May 22, 2020.
    Public hearing. If anyone contacts us requesting a public hearing 
on or before April 13, 2020, we will hold a hearing. Additional 
information about the hearing, if requested, will be published in a 
subsequent Federal Register document and posted at https://www.epa.gov/stationary-sources-air-pollution/phosphate-fertilizer-production-plants-and-phosphoric-acid. See SUPPLEMENTARY INFORMATION for 
information on requesting and registering for a public hearing.

ADDRESSES: You may send comments, identified by Docket ID No. EPA-HQ-
OAR-2020-0016 by any of the following methods:
     Federal eRulemaking Portal: https://www.regulations.gov/ 
(our preferred method). Follow the online instructions for submitting 
comments.
     Email: a-and-r-docket@epa.gov. Include Docket ID No. EPA-
HQ-OAR-2020-0016 in the subject line of the message.
     Fax: (202) 566-9744. Attention Docket ID No. EPA-HQ-OAR-
2020-0016.
     Mail: U.S. Environmental Protection Agency, EPA Docket 
Center, Docket ID No. EPA-HQ-OAR-2020-0016, Mail Code 28221T, 1200 
Pennsylvania Avenue NW, Washington, DC 20460.
     Hand/Courier Delivery: EPA Docket Center, WJC West 
Building, Room 3334, 1301 Constitution Avenue NW, Washington, DC 20004. 
The Docket Center's hours of operation are 8:30 a.m.-4:30 p.m., Monday-
Friday (except federal holidays).
    Instructions: All submissions received must include the Docket ID 
No. for this rulemaking. Comments received may be posted without change 
to https://www.regulations.gov/, including any personal information 
provided. For detailed instructions on sending comments and additional 
information on the rulemaking process, see the SUPPLEMENTARY 
INFORMATION section of this document.

FOR FURTHER INFORMATION CONTACT: For questions about this proposed 
action, contact Mr. John Feather, Sector Policies and Programs Division 
(D243-04), Office of Air Quality Planning and Standards, U.S. 
Environmental Protection Agency, Research Triangle Park, North Carolina 
27711; telephone number: (919) 541-3052; fax number: (919) 541-4991 and 
email address: feather.john@epa.gov.

SUPPLEMENTARY INFORMATION:
    Public hearing. Please contact Ms. Nancy Perry at (919) 541-5628 or 
by email at perry.nancy@epa.gov to request a public hearing, to 
register to speak at the public hearing, or to inquire as to whether a 
public hearing will be held.
    Docket. The EPA has established a docket for this rulemaking under 
Docket ID No. EPA-HQ-OAR-2020-0016. All documents in the docket are 
listed in Regulations.gov. 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 either electronically in 
Regulations.gov or in hard copy at the EPA Docket Center, Room 3334, 
WJC West Building, 1301 Constitution Avenue NW, Washington, DC. The 
Public Reading Room is open from 8:30 a.m. to 4:30 p.m., Monday through 
Friday, excluding

[[Page 19413]]

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.
    Instructions. Direct your comments to Docket ID No. EPA-HQ-OAR-
2020-0016. The EPA's policy is that all comments received will be 
included in the public docket without change and may be made available 
online at https://www.regulations.gov/, including any personal 
information provided, unless the comment includes information claimed 
to be CBI or other information whose disclosure is restricted by 
statute. Do not submit information that you consider to be CBI or 
otherwise protected through https://www.regulations.gov/ or email. This 
type of information should be submitted by mail as discussed below.
    The EPA may publish any comment received to its public docket. 
Multimedia submissions (audio, video, etc.) must be accompanied by a 
written comment. The written comment is considered the official comment 
and should include discussion of all points you wish to make. The EPA 
will generally not consider comments or comment contents located 
outside of the primary submission (i.e., on the Web, cloud, or other 
file sharing system). For additional submission methods, the full EPA 
public comment policy, information about CBI or multimedia submissions, 
and general guidance on making effective comments, please visit https://www.epa.gov/dockets/commenting-epa-dockets.
    The https://www.regulations.gov/ website allows you to submit your 
comment anonymously, which means the EPA will not know your identity or 
contact information unless you provide it in the body of your comment. 
If you send an email comment directly to the EPA without going through 
https://www.regulations.gov/, your email address will be automatically 
captured and included as part of the comment that is placed in the 
public docket and made available on the internet. If you submit an 
electronic comment, the EPA recommends that you include your name and 
other contact information in the body of your comment and with any 
digital storage media you submit. If the EPA cannot read your comment 
due to technical difficulties and cannot contact you for clarification, 
the EPA may not be able to consider your comment. Electronic files 
should not include special characters or any form of encryption and be 
free of any defects or viruses. For additional information about the 
EPA's public docket, visit the EPA Docket Center homepage at https://www.epa.gov/dockets.
    Submitting CBI. Do not submit information containing CBI to the EPA 
through https://www.regulations.gov/ or email. Clearly mark the part or 
all of the information that you claim to be CBI. For CBI information on 
any digital storage media that you mail to the EPA, mark the outside of 
the digital storage media as CBI and then identify electronically 
within the digital storage media the specific information that is 
claimed as CBI. In addition to one complete version of the comments 
that includes information claimed as CBI, you must submit a copy of the 
comments that does not contain the information claimed as CBI directly 
to the public docket through the procedures outlined in Instructions 
above. If you submit any digital storage media that does not contain 
CBI, mark the outside of the digital storage media clearly that it does 
not contain CBI. Information not marked as CBI will be included in the 
public docket and the EPA's electronic public docket without prior 
notice. Information marked as CBI will not be disclosed except in 
accordance with procedures set forth in 40 Code of Federal Regulations 
(CFR) part 2. Send or deliver information identified as CBI only to the 
following address: OAQPS Document Control Officer (C404-02), OAQPS, 
U.S. Environmental Protection Agency, Research Triangle Park, North 
Carolina 27711, Attention Docket ID No. EPA-HQ-OAR-2020-0016.
    Preamble acronyms and abbreviations. We use 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:

ACI activated carbon injection
BTF beyond-the-floor
CAA Clean Air Act
CBI Confidential Business Information
CFR Code of Federal Regulations
EPA Environmental Protection Agency
GMCS Gore Mercury Control System
HAP hazardous air pollutant(s)
ICR information collection request
lb/yr pounds per year
MACT maximum achievable control technology
mg/dscm milligram per dry standard cubic meter
NAICS North American Industry Classification System
NESHAP national emission standards for hazardous air pollutants
NTTAA National Technology Transfer and Advancement Act
OAQPS Office of Air Quality Planning and Standards
OMB Office of Management and Budget
ppm parts per million
SBA Small Business Administration
tph tons per hour
tpy tons per year
UPL upper prediction limit

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

Table of Contents

I. General Information
    A. Does this action apply to me?
    B. Where can I get a copy of this document and other related 
information?
    C. What is the source of the Agency's authority for taking this 
action?
    D. What action is the Agency taking?
II. Background
    A. Why is the EPA issuing this proposed review?
    B. What are the issues raised by the petitioner?
III. Analytical Procedures and Decision-Making
    A. What mercury emissions and phosphate rock composition data 
were collected?
    B. How did we calculate the MACT floor limit?
    C. What is our BTF Analysis?
IV. Summary of Cost, Environmental, and Economic Impacts
V. Request for Comments
VI. Statutory and Executive Order Reviews
    A. Executive Order 12866: Regulatory Planning and Review and 
Executive Order 13563: Improving Regulation and Regulatory Review
    B. Executive Order 13771: Reducing Regulation and Controlling 
Regulatory Costs
    C. Paperwork Reduction Act (PRA)
    D. Regulatory Flexibility Act (RFA)
    E. Unfunded Mandates Reform Act (UMRA)
    F. Executive Order 13132: Federalism
    G. Executive Order 13175: Consultation and Coordination With 
Indian Tribal Governments
    H. Executive Order 13045: Protection of Children From 
Environmental Health Risks and Safety Risks
    I. Executive Order 13211: Actions Concerning Regulations That 
Significantly Affect Energy Supply, Distribution, or Use
    J. National Technology Transfer and Advancement Act (NTTAA)
    K. Executive Order 12898: Federal Actions To Address 
Environmental Justice in Minority Populations and Low-Income 
Populations

I. General Information

A. Does this action apply to me?

    Table 1 of this preamble lists the NESHAP and associated regulated 
industrial source category that is the subject of this proposal. Table 
1 is not intended to be exhaustive, but rather provides a guide for 
readers regarding the entities that this proposed action is likely to 
affect. The proposed standards, once promulgated, will be directly 
applicable to the affected sources.

[[Page 19414]]

Federal, state, local, and tribal government entities would not be 
affected by this proposed action. As defined in the Initial List of 
Categories of Sources Under Section 112(c)(1) of the Clean Air Act 
Amendments of 1990 (see 57 FR 31576, July 16, 1992) and Documentation 
for Developing the Initial Source Category List, Final Report (see EPA-
450/3-91-030, July 1992), the Phosphoric Acid Manufacturing source 
category includes any facility engaged in the production of phosphoric 
acid. The category includes, but is not limited to, production of wet-
process phosphoric acid and superphosphoric acid.

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

B. 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 action is available on the internet. Following signature by the 
EPA Administrator, the EPA will post a copy of this proposed 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 
of the proposal and key technical documents at this same website.
    A redline version of the regulatory language that incorporates the 
proposed changes is available in the docket for this action (Docket ID 
No. EPA-HQ-OAR-2020-0016).

C. What is the source of the Agency's authority for taking this action?

    The statutory authority for this action is provided by section 112 
of the Clean Air Act (CAA) (42 U.S.C. 7412). A technology-based NESHAP 
has been developed for major sources in the Phosphoric Acid 
Manufacturing source category. ``Major sources'' are those that emit, 
or have the potential to emit, any single hazardous air pollutant (HAP) 
at a rate of 10 tons per year (tpy) or more, or 25 tpy or more of any 
combination of HAP. For major sources, MACT standards reflect the 
maximum degree of emission reductions of HAP achievable (after 
considering cost, energy requirements, and non-air quality health and 
environmental impacts). In developing MACT standards, CAA section 
112(d)(2) directs the EPA to consider the application of measures, 
processes, methods, systems, or techniques, including, but not limited 
to, those that reduce the volume of or eliminate HAP emissions through 
process changes, substitution of materials, or other modifications; 
enclose systems or processes to eliminate emissions; collect, capture, 
or treat HAP when released from a process, stack, storage, or fugitive 
emissions point; are design, equipment, work practice, or operational 
standards; or any combination of the above. In setting MACT standards, 
the statute specifies certain minimum stringency requirements, which 
are referred to as ``MACT floor'' requirements, and which may not be 
based on cost considerations. See CAA section 112(d)(3) for more 
information. For new sources, the MACT floor cannot be less stringent 
than the emission control achieved in practice by the best-controlled 
similar source. The MACT standards for existing sources can be less 
stringent than floors for new sources, but they cannot be less 
stringent than the average emission limitation achieved by the best 
performing 12 percent of existing sources in the category or 
subcategory (or the best-performing five sources for categories or 
subcategories with fewer than 30 sources). In developing MACT 
standards, we must also consider control options we call ``beyond-the-
floor'' (BTF) that are more stringent than the floor, under CAA section 
112(d)(2). We may establish standards more stringent than the floor, 
based on the consideration of the cost of achieving the emissions 
reductions, any non-air quality health and environmental impacts, and 
energy requirements. The EPA may amend MACT floor determinations if 
they were improperly set (Medical Waste Institute and Energy Recovery 
Council v. EPA, 645 F. 3d 420, 425-27 (D.C. Cir. 2011)). In the 
Phosphoric Acid Manufacturing source category, the calciners' mercury 
emissions are effectively uncontrolled, so their actual emissions are 
considered to be the average emission limitation achieved by the best-
performing sources.

D. What action is the Agency taking?

    The EPA is proposing to amend 40 CFR part 63, subpart AA. This 
amendment is in response to a petition for a rulemaking to amend the 
2015 Rule's calciner mercury MACT floor emission limit, submitted by 
PCS Phosphate to the Agency on September 6, 2016. The petition is 
available in the docket for this action (Docket ID No. EPA-HQ-OAR-2020-
0016). The EPA proposes to raise the mercury MACT floor-based limit for 
existing calciners from 0.14 milligrams per dry standard cubic meter 
(mg/dscm) at 3-percent oxygen (O2) to 0.23 mg/dscm at 3-
percent O2. Table 1 to Subpart AA of Part 63--Existing 
Source Emission Limits is reproduced in its entirety at the end of this 
preamble for the sake of clarity. However, the EPA is proposing to 
amend only the existing source mercury limit for phosphate rock 
calciners, along with its footnote indicating the applicable compliance 
date. This proposed amendment would not impact any other aspect of the 
table or regulatory text.

II. Background

A. Why is the EPA issuing this proposed review?

    In August 2015, we published final amendments to the Phosphoric 
Acid Manufacturing and Phosphate Fertilizer Production NESHAP (80 FR 
50386, August 19, 2015). As part of that action, we established MACT-
based mercury emissions limits for new and existing calciners within 
the Phosphoric Acid Manufacturing source category. These limits were 
based on emissions data from the six identical calciners at the PCS 
Aurora facility. Because these six sources are of identical design and 
use the same fuel and feed, we determined that they should be treated 
as a single source for purposes of MACT floor development. As a result, 
we combined the emission test results for the different calciners into 
a single database that we used as the basis to set MACT floor emissions 
limits for both new and existing sources. We also evaluated a BTF 
option for MACT for existing calciners but did not select the BTF 
option as MACT because we determined that the economic impacts to the 
facility would not be reasonable. We did set a BTF limit for new 
calciners.
    Following promulgation of the 2015 Rule, PCS Phosphate petitioned 
for reconsideration, pursuant to section 307(d)(7)(B) of the CAA, on 
October 16, 2015. The EPA granted the petition for reconsideration of 
the issues presented at the time relating to the compliance schedule 
for oxidation reactor emissions and absorber liquid-to-gas ratios. This 
reconsideration was finalized on September 13, 2017. However, 
subsequent to this petition for reconsideration, compliance testing of 
the calciners for mercury emissions in

[[Page 19415]]

2016 showed that three calciners at the Aurora facility exceeded the 
MACT limit, with the three other calciners near the limit. For 
reference, the mean calciner compliance emissions in 2016 were 0.143 
mg/dscm at 3-percent O2, higher than the MACT limit of 0.14 
mg/dscm at 3-percent O2. The mean of these emissions was 44 
percent higher than the mean of the data from the 2010 and 2014 
information collection request (ICR) that was used to develop the 2015 
Rule's emission limit. On May 10, 2016, PCS Phosphate submitted a 
letter to the EPA requesting a revision to the calciner mercury MACT 
floor standard. On September 6, 2016, PCS Phosphate added the calciner 
mercury limit to its earlier petition for reconsideration. This 
additional request was not raised with reasonable specificity or within 
60 days of the publication of the 2015 Rule, so the mercury MACT floor 
issue was not included in the reconsideration. However, on the basis of 
the test data presented, the EPA was convinced there was justification 
to review the mercury calciner limit and include new emissions data in 
that analysis. Because of that evaluation, as explained below, the EPA 
is now proposing a revised mercury emissions standard for existing 
calciners.

B. What are the issues raised by the petitioner?

    PCS Phosphate raised concerns about whether the mercury MACT limit 
accurately represents the average emission limitation achieved by the 
calciners at their facility in Aurora, North Carolina. These calciners, 
on which the MACT floor was based, consistently showed emissions above 
the calculated floor level. This was believed to be due to two factors:
     The 2010 and 2014 emission test data used in calculating 
the MACT floor were obtained while the calciners were operating at 
throughput rates that averaged 52 wet tons per hour (tph), due in part 
to mining limitations. Based on industry statements and values from 
state-mandated test reports, these calciners typically operate at a 
feed throughput rate of greater than 65 wet tph. This low throughput 
during initial tests biased the emissions data low.
     The mercury content of the feed material varies 
significantly. The limited data available from the 2010 and 2014 tests 
did not fully capture this variability or the range of mercury content 
that may be expected to be present in the phosphate rock. Changes in 
feed mercury content directly affect mercury emissions.

III. Analytical Procedures and Decision-Making

A. What mercury emissions and phosphate rock composition data were 
collected?

    To develop our 2015 Rule, we obtained initial ICR data from PCS 
Aurora in 2010 that consisted of three test runs performed during one 
stack test of a single calciner (three test runs during each stack 
test). These data were collected using EPA Method 30B, the same method 
used for compliance testing. Speciated mercury data, differentiating 
elemental mercury from total mercury, was also obtained by the ASTM 
D6784-02 (Ontario-Hydro) method. Due to concerns about basing a MACT 
floor on such a limited dataset, in 2014 an additional nine test runs 
were performed during three stack tests of a different calciner. Based 
on data from these 12 test runs, we calculated a MACT floor using the 
99-percent upper prediction limit (UPL). The 2015 UPL data and analysis 
are included in this docket (Docket ID No. EPA-HQ-OAR-2020-0016).
    Each year from 2016 to 2019, PCS Aurora measured mercury emissions 
from each of the six calciners with three-run stack tests. In addition, 
the facility performed a study varying feed throughput rates and stack 
test sampling times. During every test run from 2016 and on, PCS Aurora 
measured the feed ore mercury concentration. PCS Aurora also analyzed 
the mercury content of an additional 48 samples of ore (rock) collected 
from core samples to better characterize the expected mercury in feed 
ore in future years. In total, our dataset for this MACT floor analysis 
includes 104 stack test runs under normal operating rates. These new 
data provide more information that better characterize average calciner 
mercury emissions. This rule's data and analysis are also available in 
the MACT floor memorandum in the docket (Docket ID No. EPA-HQ-OAR-2020-
0016).
    On the basis of the new data provided, we do not believe now that 
the testing used to set the MACT limit in the 2015 Rule represented the 
emissions that calciners achieve during normal operations. We agree 
that the measured levels could not be achieved were the sources 
operating under normal loads. Compliance testing data from 2016 through 
2019 has consistently shown emissions exceeding the MACT floor limit 
when operating at normal loads. Each year the average emissions tested 
under normal loads exceeded the MACT floor. Every test run in 2018 and 
2019 exceeded the MACT limit, as did the three tests in 2017 operating 
under normal loads and most of the other non-compliance test runs. The 
average emissions indicated from the new data are significantly higher 
than those from the data used to set the MACT limit in the 2015 Rule. 
Furthermore, composition testing shows that the 2010 and 2014 ICR tests 
did not represent the full range of the on-site phosphate rock's 
mercury content. The mercury composition average in feed phosphate rock 
has increased since the ICR tests, and from 2016 to 2019. Testing has 
also shown an unanticipated degree of variation of mercury content in 
phosphate rock, both in the short-term feed and in on-site ore that 
would be used as feed in the future. Mercury emissions are a function 
of both the rate of input feed and the concentration of mercury in the 
feed. Additional mercury entering the calciner, whether by more feed 
entering the calciner or a higher concentration of mercury in the feed, 
leads to an increased magnitude of mercury emissions. Calciner airflow 
rates are insensitive to the throughput rate, keeping fairly constant 
without regard for how much feed is being processed. The increased 
concentrations of mercury emissions that these new data show are due to 
the increased amount of mercury entering into the calciners through the 
feed, not because of process inefficiencies or problems with operating 
conditions. Therefore, for purposes of calculating the MACT floor, we 
have used emissions data from 2016 through 2019, as well as studies of 
the variance in the mercury in ore at the Aurora site.

B. How did we calculate the MACT floor limit?

    In general, MACT floor analyses involve an assessment of the 
emissions from the best-performing sources in a source category using 
the available emissions information. For each source category, the 
assessment involves a review of emissions data with an appropriate 
accounting for emissions variability. Various methods of estimating 
emissions can be used if the methods can be shown to provide reasonable 
estimates of the actual emissions from a source or sources.
    To determine the MACT floors for phosphate rock calciners, we used 
the arithmetic average of all the available emissions data from 2016 
through 2019 and accounted for emissions variability. We accounted for 
emissions variability in setting floors not only because variability is 
an aspect of performance, but because it is reasonable to assess 
performance over time and to account for test method variability. The 
United

[[Page 19416]]

States Court of Appeals for the District of Columbia Circuit has 
recognized that the EPA may consider variability in estimating the 
degree of emission reduction achieved by best-performing sources and in 
setting MACT floors (Mossville Environmental Action Now v. EPA, 370 
F.3d 1232, 1241-42 (D.C. Cir. 2004)). For more detailed information 
about the EPA's analytical process in using the UPL to calculate MACT 
floors, see the 2015 Rule's UPL memorandum, included in this docket 
(Docket ID No. EPA-HQ-OAR-2020-0016).
    The dataset for this analysis used the 104 stack test runs that 
were taken under normal operating conditions. Because the calciners 
typically operate at 65 tph of feed or more, we excluded from the 
analysis any test runs that were conducted when feed rates were below 
65 tph. These lower feed rates do not represent normal operation and 
would bias the result low. This excluded the 12 runs from the 2010 and 
2014 ICR tests, along with 13 runs from tests in 2016 and 2017 that 
specifically sought to vary parameters to better understand the 
emission results.
    The 2015 Rule MACT floor analysis used the stack test data to 
calculate the average emissions and the 99-percent UPL to account for 
variability in the testing and calciner operations. Our revised 
analysis in this proposal relies on the statistical analysis of the new 
data set that represent emissions from normal operations. In addition, 
we are now using data on the mercury concentrations in phosphate ore 
areas yet to be mined to account for variability that would occur in 
the future. We determined the variance of the ore mercury concentration 
data and added that to the variance of the emissions test data. The 
relative standard deviation of mercury content in the future feed is 
slightly greater than that of mercury emissions and varies 
independently. We used this 99-percent lognormal UPL with independent 
future feed variance to calculate the MACT floor limit for existing 
rock calciners of 0.23 mg/dscm on a 3-percent O2 basis. 
Table 2 of this preamble lists the proposed mercury emission limit for 
phosphate rock calciners. For more information, see the MACT floor 
memorandum in the docket for this rulemaking (Docket ID No. EPA-HQ-OAR-
2020-0016).

     Table 2--Proposed Emisson Limit for Mercury From Phosphate Rock
                 Calciners at Phosphoric Acid Facilities
------------------------------------------------------------------------
              Pollutant                 Limit             Units
------------------------------------------------------------------------
Existing sources:
    Mercury..........................    0.23   mg/dscm @3% O2
------------------------------------------------------------------------

C. What is our BTF analysis?

    The 2015 Rule evaluated possible BTF control options. That analysis 
focused on the activated carbon injection (ACI) system and Gore Mercury 
Control System (GMCS), largely based on site-specific quotes provided 
by the PCS Aurora facility. These technologies both employ adsorption 
to capture mercury emissions from the calciners with feasible mercury 
reductions of 90 percent. An ACI system injects halogenated powdered 
activated carbon into the airflow, oxidizing elemental mercury which 
adsorbs to the activated carbon. The GMCS consists of a series of 
modules containing catalysts and sorbents which capture all forms of 
mercury passing through. The GMCS requires a higher capital cost than 
the ACI system, with an associated higher annualized cost based on 
conditions at the time, so the 2015 Rule based its evaluations on the 
lower cost of the ACI system. The analysis showed a cost effectiveness 
of $29,800 to $36,400 per pound of mercury reduced and an economic 
impact to the purified acid process of approximately 0.9 percent to 5.3 
percent. This was determined to be cost effective, but the significant 
economic impact to the facility led to the EPA's previous decision to 
not pursue the BTF option.
    This current review also used the 2015 Rule's control costs for 
evaluations of BTF mercury removal cost effectiveness and its related 
economic impact. Based on the mercury emissions data available for this 
proposal, mercury emissions are estimated to be 264 pounds per year 
(lb/yr), compared to the earlier estimate of 169 lb/yr during the 2015 
Rule. Due to this, the ACI sorbent rate and associated cost were 
adjusted to account for the higher mercury removal. Otherwise, the ACI 
system parameters are unchanged from the 2015 Rule's cost analysis. The 
GMCS capacity was sufficient to achieve this higher mercury removal 
without modifications or increased cost. Based on these adjustments, we 
estimate that the total capital cost of the ACI system is $20.1 million 
and the total annualized cost is $5.69 million per year. This results 
in a cost per pound for mercury removal of $23,900. The GMCS total 
capital cost is $36.4 million and the total annualized cost is $4.99 
million per year, with a cost per pound for mercury removal of $21,000. 
We still consider these controls to be cost effective.
    PCS merged with Agrium to form Nutrien in 2018, after the 2015 Rule 
was promulgated. As was the case during the 2015 Rule's analysis, 
annualized control technology costs represent less than 1 percent of 
the revenue for the Aurora facility's parent company, which is now 
Nutrien. Parent company revenue is significantly higher due to the 
merger, so control costs now comprise a smaller proportion of the 
company revenue than before. However, operations at the PCS Aurora 
facility have not substantively changed since our 2015 Rule's analysis. 
The total costs of the ACI system are also higher due to the fact that 
the amount of mercury removed increases correspondingly with the 
increased estimates of mercury emissions. In our economic analysis in 
the 2015 Rule, we determined that the economic impacts on the specific 
process line being controlled were unreasonable and did not impose a 
BTF option. In our new analysis, control costs have increased. These 
control costs represent more than 1 percent of the purified acid 
process revenue associated with the calciners. We find the costs for 
the ACI system are too high to justify pursuing the BTF option. For 
more detail, see the BTF memorandum in the docket for this rulemaking 
(Docket ID No. EPA-HQ-OAR-2020-0016).

IV. Summary of Cost, Environmental, and Economic Impacts

    Only the PCS Aurora facility and its six calciners would be 
affected by the change to the existing calciner MACT floor proposed in 
this action. We are proposing to raise the MACT floor based on new data 
from the existing calciners. Since neither this amendment nor the 2015 
Rule requires controls, we do not anticipate a change in actual mercury 
emissions as a result of this proposed rule. More mercury emissions 
will be allowable due to raising the MACT floor. However, currently we 
estimate total actual emissions of mercury from all six calciners to be 
264 lb/yr, less than the 352 lb/yr conservatively estimated in the 2015 
Rule, so we continue to anticipate no adverse environmental impact.
    The 2015 Rule set a mercury limit of 0.14 mg/dscm at 3 percent that 
current operations cannot achieve under normal operations. Without this 
amendment, additional controls such as the ACI system would be 
necessary to comply with that standard. If this amendment is

[[Page 19417]]

finalized, the value of those controls would represent a cost-savings 
for the facility, since those expenditures would be expected to no 
longer be necessary. The costs of installing new ACI control equipment 
to meet the 2015 Rule's calciner mercury standard were estimated to 
comprise a present value cost of approximately $26 million (2017 
dollars) discounted at 7 percent to 2019 over a 5-year analytical 
period. Therefore, this action will result in a total cost savings of 
$26 million. For more detail, see the economic impact analysis 
memorandum in the docket (Docket ID No. EPA-HQ-OAR-2020-0016).

V. Request for Comments

    The EPA seeks public comments on the issues addressed in this 
proposed rule, as described in this document. We are soliciting 
comments on the proposed revised standards, particularly the method of 
determining the average emission limitation achieved by the calciners 
for mercury emissions and costs of mercury control.

VI. Statutory and Executive Order Reviews

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

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

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

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

    This action is expected to be an Executive Order 13771 deregulatory 
action. Details on the estimated costs of this proposed rule can be 
found in the EPA's analysis of the potential costs and benefits 
associated with this action.

C. Paperwork Reduction Act (PRA)

    This action does not impose any new information collection burden 
under the PRA. OMB has previously approved the information collection 
activities contained in the existing regulations and has assigned OMB 
control number 2060-0361. With this action, the EPA is seeking comments 
on proposed amendments to the 40 CFR part 63, subpart AA existing rule 
language narrowly concerning the calciner mercury MACT floor. 
Therefore, the EPA believes that there are no changes to the 
information collection requirements of the 2015 Rule, so the 
information collection estimate of projected cost and hour burden from 
the 2015 Rule remains unchanged.

D. Regulatory Flexibility Act (RFA)

    I certify that this action will not have a significant economic 
impact on a substantial number of small entities under the RFA. This 
action will not impose any requirements on small entities. The single 
facility currently subject to the calciner mercury MACT floor 
requirements of 40 CFR 63, subpart AA is not a small entity.

E. Unfunded Mandates Reform Act (UMRA)

    This action does not contain an unfunded mandate of $100 million or 
more as described in UMRA, 2 U.S.C. 1531-1538, and does not 
significantly or uniquely affect small governments. The action imposes 
no enforceable duty on any state, local, or tribal governments or the 
private sector.

F. Executive Order 13132: Federalism

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

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

    This action does not have tribal implications as specified in 
Executive Order 13175. This action 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.

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

    The EPA interprets Executive Order 13045 as applying to those 
regulatory actions that concern environmental health or safety risks 
that the EPA has reason to believe may disproportionately affect 
children, per the definition of ``covered regulatory action'' in 
section 2-202 of the Executive Order. This action is not subject to 
Executive Order 13045 because it does not concern an environmental 
health risk or safety risk.

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

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

J. National Technology Transfer and Advancement Act (NTTAA)

    This action does not involve any new technical standards.

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

    The EPA believes that this action does not have disproportionately 
high and adverse human health or environmental effects on minority 
populations, low-income populations, and/or indigenous peoples, as 
specified in Executive Order 12898 (59 FR 7629, February 16, 1994).
    The environmental justice finding in the 2015 Rule remains relevant 
in this action, which seeks comments on proposed amendments to the 40 
CFR part 63, subpart AA existing rule language narrowly concerning the 
calciner mercury MACT floor.

List of Subjects in 40 CFR Part 63

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

Andrew Wheeler,
Administrator.
    For the reasons set forth in the preamble, the EPA proposes to 
amend 40 CFR part 63 as follows:

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

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

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

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

0
2. Table 1 to Subpart AA of Part 63--Existing Source Emission Limits is 
amended to read as follows:

[[Page 19418]]

                      Table 1 to Subpart AA of Part 63--Existing Source Emission Limits a b
----------------------------------------------------------------------------------------------------------------
                                          You must meet the emission limits for the specified pollutant . . .
 For the following existing sources . --------------------------------------------------------------------------
                 . .                       Total fluorides         Total particulate             Mercury
----------------------------------------------------------------------------------------------------------------
Wet-Process Phosphoric Acid Line.....  0.020 lb/ton of
                                        equivalent P2O5 feed.
Superphosphoric Acid Process Line c..  0.010 lb/ton of
                                        equivalent P2O5 feed.
Superphosphoric Acid Submerged.......  0.020 lb/ton of
                                        equivalent P2O5 feed.
Line with a Submerged Combustion       .......................  2,150 lb/ton of
 Process.                                                        phosphate rock feed.
Phosphate Rock Dryer.................  .......................  0.181 g/dscm...........
Phosphate Rock Calciner..............  9.0E-04 lb/ton of rock   .......................  0.23 mg/dscm corrected
                                        feed d.                                           to 3 percent oxygen.e
----------------------------------------------------------------------------------------------------------------
a The existing source compliance data is June 10, 2002, except as noted.
b During periods of startup and shutdown, for emission limits stated in terms of pounds of pollutant per ton of
  feed, you are subject to the work practice standards specified in Sec.   63.602(f).
c Beginning on August 19, 2018, you must include oxidation reactors in superphosphoric acid process lines when
  determining compliance with the total fluorides limit.
d Compliance date is August 19, 2015.
e Compliance date is [DATE OF PUBLICATION OF THE FINAL RULE IN THE FEDERAL REGISTER].

[FR Doc. 2020-06930 Filed 4-6-20; 8:45 am]
 BILLING CODE 6560-50-P