time, and so might emissions. Thus, the Agency disagrees with the
commenter's argument. We have determined that a new performance test
conducted under a particular operating range should invalidate a
previous operating range that was established under different operating
conditions. An operating limit (e.g., an operating range, a minimum
operating level, or maximum operating level) is established using the
most recent performance test, or in certain instances, a series of
tests (potentially including historical tests). However, in all cases,
if owners or operators demonstrate compliance with an emission limit
during the most recent performance test, and during this performance
test an owner's or operator's control device was operating outside the
previously established operating limit, the owner or operator must
establish a new operating limit that incorporates that most recent
performance test.
    iv. Approving Operating Ranges--Comment. Several commenters support
the EPA's proposal to eliminate the requirement that facilities may not
implement new operating parameter ranges until the Administrator has
approved them, or 30 days have passed since submission of the
performance test results. A commenter pointed out that 40 CFR
63.605(d)(1)(iii)(B), as proposed, does not provide the 30-day default
period for the effectiveness of the new ranges if the EPA Administrator
does not act; therefore, as currently set forth in the proposed rule,
sources will be left in limbo waiting for the EPA Administrator to
respond before they can implement new ranges. A commenter suggested
that the EPA revise the proposed regulatory language to require
submission of the new ranges to EPA, but delete the requirement to
request and obtain EPA's approval of the new ranges. Similarly, another
commenter requested the EPA clarify the process for establishing new
equipment operating ranges following source performance testing. This
commenter contended that facilities should have the ability to update
operating parameters if they desire based on source testing, and the
facility should be required to submit the new

ranges, but not be required to obtain EPA's approval of the new ranges.
    In addition, a commenter requested that the EPA clarify how
revising the proposed regulatory language to require submission of the
new ranges to the EPA, but deleting the requirement to request and
obtain EPA's approval of the new ranges, will affect possible
obligations to undertake permit modifications of title V permits under
40 CFR part 70. This commenter stated that such administrative
processes are not fully anticipated in the proposed rule.
    Response. In the proposed NESHAP subpart AA, the Agency intended
that facilities not be required to obtain approval, and, instead,
immediately comply with a new operating limit when it is developed and
submitted to the Administrator. Therefore, the requirements at proposed
40 CFR 63.605(d)(1)(iii)(B) have been revised in the final rule at 40
CFR 63.605(d)(1)(ii)(B), as the commenter requests, to remove the
requirement that facilities must request and obtain approval of the
Administrator for changing operating limits. Furthermore, the Agency
suggests that the title V permit be modified as soon as the
Administrator is notified of a change in an operating limit. The Agency
acknowledges that corrections and modifications to permit applications
could become a problem for a facility, particularly if the
Administrator determines the operating limit is not appropriate after a
facility has already applied for the change to be made in its air
permit; however, we expect this scenario to be rare.
    c. Translation of Total Fluoride to HF Emission Limits--Comment.
With regard to the proposed NESHAP subpart AA, several commenters
opposed the use of EPA Method 320 to test for HF, and supported the
retention of a total fluoride compliance standard and associated
testing using EPA Method 13A or 13B. These commenters argued that EPA
Method 320 leads to unreliable and unrepresentative results because
some reactive fluoride compounds in the exhaust may form HF in the
sampling equipment. The commenters explained that complex reactions
leading to fluoride emissions occur not only in the processing units
located at the Phosphoric Acid Manufacturing source category, but also
in the scrubber systems designed to remove fluoride from the stack
gases. Commenters stated that these reactions result in a mix of
gaseous, aerosol, and particle bound fluoride (all three phases) in the
stack gas, in the form of compounds like silica tetrafluoride, various
fluorosilicate aerosols and/or droplets, ammonium fluoride, ammonium
bifluoride, and/or ammonium fluorosilicate; and argued that these
compounds have the potential to be captured in a Method 320 sampling
equipment, biasing or interfering with the results of the sampling.
Commenters specified that the EPA Method 320 sampling conducted in
response to the EPA's information requests demonstrated that
SiF4 readily reacts with water vapor in the stack gas
producing HF and silicon hydroxide; and one of the commenters provided
information showing that this reaction is dependent on temperature,
moisture, and residence time in the sampling system. Additionally, some
of the commenters listed technical issues that they encountered during
the EPA Method 320 sampling that they conducted in response to EPA's
information requests. These commenters recommended certain procedures
be followed when conducting EPA Method 320 at the Phosphoric Acid
Manufacturing source category; however, they also cautioned that their
recommendations would not resolve all of the inherent problems with the
sampling and analysis process. The commenters also expressed concern
over the increase in testing costs from using EPA Method 320 instead of
EPA Method 13A or 13B, citing an increase of at least 3 to 4 times when
using EPA Method 320 instead of EPA Method 13B.
    We also received comments regarding the option to use Fourier
transform infrared spectroscopy (FTIR) HF CEMS as a continuous
monitoring compliance approach for HF at NESHAP subpart BB affected
sources. One commenter contended that the EPA must consider requiring
continuous HF emission monitoring before finalizing the proposal, and
pointed out that there is a HF sensor (suitable for 0-10 part per
million (ppm) monitoring range and a 0.1 ppm resolution) available for
the Ultima X Series Gas Monitors. Several commenters opposed this
option and cited EPA's technical memorandum ``Approach for Hydrogen
Fluoride Continuous Emission Monitoring and Compliance Determination
with EPA Method 320.'' They argued that the option to use FTIR HF CEMS
exceeds the capabilities of existing technology, and that there are no
details on the required methods to implement such a system or known
field demonstrations of this type of system, and that the option has
not been proven.
    Finally, one commenter requested the EPA explain its technical
basis for abandoning the longstanding total fluoride surrogate for HF.
The commenter argued that the EPA has established similar surrogacy
relationships to measure HAP in other regulated source categories in
the past.
    Response. In response to the January 2014 CAA section 114 request,
processes at the Phosphoric Acid Manufacturing source category were
tested for HF using EPA Method 320. Based on those results, the Agency
concluded that moving to a form of the standard that requires HF (the
target HAP) to be measured (but retaining the same numeric values as
the current total fluoride standards) would be achievable by all
facilities. However, in light of information provided by commenters,
the Agency has re-evaluated the proposed revision to the standard and
determined that EPA Method 320 is not an appropriate test method for
accurately measuring HF emissions from process lines in this specific
source category due to the complex and often incomplete chemical
reactions with silicon compounds in these sources. Accordingly, the
Agency is not adopting the proposed HF standards in NESHAP subpart AA.
The Agency has determined that SiF4 and water are naturally
present in the exhaust gases of the processes located at the Phosphoric
Acid Manufacturing source category; and these chemical compounds will
react to form HF and silicon dioxide in the near field from the
emission point on release into the atmosphere. The Agency has reviewed
a study \10\ stating that the equilibrium of this chemical reaction is
highly dependent on temperature such that as temperature increases, the
conversion of SiF4 to HF increases. At high sampling
temperatures (i.e., sampling temperatures ranged from about 150 to 300
degrees Fahrenheit during the EPA Method 320 testing conducted pursuant
to the January 2014 CAA section 114 requests), there is nearly a
complete conversion of SiF4 to HF. Therefore, as
SiF4 is captured in the EPA Method 320 sampling system, it
may react with moisture (water) to form HF, resulting in HF
measurements from this source category that are biased. That is, due to
the chemical interactions and reactions with moisture at different
temperatures, some of the HF emissions detected by EPA Method 320 may
not represent HF that exists in the exhaust stack or HF released from
phosphoric acid production.
---------------------------------------------------------------------------

    \10\ Koogler & Associates, Inc. ``Technical Evaluation of the
Measurement Limitations Associated with Source HF Emissions by EPA
Method 320.'' January 21, 2015.
---------------------------------------------------------------------------

    As a result of our determination to not adopt the proposed HF
standards, the

Agency has retained the current total fluoride limits (lb total F/ton
P2O5 feed) measured using EPA Method 13A or 13B
in NESHAP subpart AA as a surrogate for the HAP HF, rather than HF
emission limits using EPA Method 320. Furthermore, in light of this
conclusion, the Agency is not finalizing an option to use FTIR HF CEMS.
In the final rule promulgated on June 10, 1999 (64 FR 31358), the EPA
explained that total fluoride was used as a surrogate for HF to
establish MACT for emissions from process sources because no direct
measurements of HF were available and because the NSPS are based on
total F. On November 7, 2014, we proposed HF emission limits in an
attempt to base the standard on the specific HAP (HF) that is emitted
by this source category because we concluded that new technology (EPA
Method 320) allows for direct measurement of HF, and because it is
preferred to measure the listed HAP directly when possible. However, in
light of the chemical interactions that may occur at this source
category during sample collection using EPA Method 320 (skewing HF
testing results), we are retaining the long-standing surrogate of total
fluoride for HF and the annual testing with EPA Method 13A or 13B.
Results from EPA Method 13A or 13B testing include all fluoride
compounds, including HF. Furthermore, since the control of total
fluoride and HF from process sources at this source category is
accomplished with the same control technology (scrubbers), the total
fluoride emission limits will result in installation of the MACT for HF
and the same level of HF control will be achieved regardless of how the
emission limits are expressed. The use of total fluoride as a surrogate
for HF simply changes the metric for compliance demonstration, not the
actual level of emission control achieved. As such, we are retaining
the existing total fluoride limits for all emission sources in NESHAP
subpart AA. Although, at present time, the Agency is not finalizing HF
standards in NESHAP subpart AA, it may be possible to do so in a future
rulemaking with additional data and specificity on monitoring
requirements.
4. What is the rationale for our final decisions regarding these other
changes to the Phosphoric Acid Manufacturing NESHAP and NSPS?
    For the reasons provided above and in the preamble for the proposed
rule, we are finalizing: The proposed requirement in NESHAP subpart AA
that pressure drop across an absorber must be greater than 5 inches of
water in order to use the option of measuring pressure drop as an
operating parameter; the proposed definitions for ``superphosphoric
acid process line'' (in NESHAP subpart AA) and ``superphosphoric acid
plant'' (in NSPS subpart U) to include oxidation reactors; and other
proposed clarifications and corrections.
    Additionally, for the reasons provided above, we are making the
revisions, clarifications and corrections noted in section V.F.2 in the
final rules for NESHAP subpart AA, NSPS subpart T, and NSPS subpart U.

VI. What is the rationale for our final decisions and amendments for
the Phosphate Fertilizer Production source category?

    For each issue related to the Phosphate Fertilizer Production
source category, this section provides a description of what we
proposed and what we are finalizing for the issue, the EPA's rationale
for the final decisions, and amendments and a summary of key comments
and responses. For all comments not discussed in this preamble, comment
summaries and the EPA's responses can be found in the Comment Summary
and Response document available in the docket.

A. Residual Risk Review for the Phosphate Fertilizer Production Source
Category

1. What did we propose pursuant to CAA section 112(f) for the Phosphate
Fertilizer Production source category?
    Pursuant to CAA section 112(f), we conducted a residual risk review
and presented the results of this review, along with our proposed
decisions regarding risk acceptability and ample margin of safety, in
the November 7, 2014, proposed rule for the Phosphate Fertilizer
Production NESHAP (79 FR 66512). The results of the risk assessment are
presented briefly below in Table 4 of this preamble, and in more detail
in the residual risk document, ``Residual Risk Assessment for Phosphate
Fertilizer Production and Phosphate Fertilizer Production Source
Categories in support of the July 2015 Risk and Technology Review Final
Rule,'' which is available in the docket for this rulemaking.

                                        Table 4--Human Health Risk Assessment for Phosphate Fertilizer Production
--------------------------------------------------------------------------------------------------------------------------------------------------------
                                             Cancer MIR  (in 1                Population  Population  Max chronic non-cancer
                                                 million)           Cancer        with        with              HI
    Category & number  of facilities     ------------------------  incidence   risks  of   risks  of ------------------------ Worst-case max  acute non-
                 modeled                   Based on    Based on   (cases per    1-in-1      10-in-1    Based on    Based on            cancer HQ
                                            actual     allowable     year)    million or  million or    actual     allowable
                                           emissions   emissions                  more        more     emissions   emissions
--------------------------------------------------------------------------------------------------------------------------------------------------------
Phosphate Fertilizer....................         0.5         0.5       0.001           0           0       0.003       0.003  HQREL = 0.4 (elemental Hg)
(11 facilities).........................                                                                                HQAEGL-1 = 0.09
                                                                                (hydrofluoric acid).
Facility-wide (11 facilities)...........         0.5  ..........       0.001           0           0         0.2  ..........  ..........................
--------------------------------------------------------------------------------------------------------------------------------------------------------

    Based on actual emissions for the Phosphate Fertilizer Production
source category, the MIR was estimated to be less than 1-in-1 million,
the maximum chronic non-cancer TOSHI value was estimated to be up to
0.003, and the maximum off-site acute HQ value was estimated to be up
to 0.4. The total estimated national cancer incidence from this source
category, based on actual emission levels, was 0.001 excess cancer
cases per year, or one case in every 1,000 years. Based on MACT-
allowable emissions for the Phosphate Fertilizer Production source
category, the MIR was estimated to be less than 1-in-1 million, and the
maximum chronic non-cancer TOSHI value was estimated to be up to 0.003.
We also found there were emissions of several PB-HAP with an available
RTR multipathway screening value, and, with the exception of Hg
compounds, the reported emissions of these HAP

(i.e., lead compounds, and cadmium compounds) were below the
multipathway screening value for each compound. One facility emitted
divalent Hg (Hg2+) above the Tier I screening threshold
level, exceeding the screening threshold by a factor of 20.
Consequently, we conducted a Tier II screening assessment for
Hg2+. This assessment uses the assumption that the
biological productivity limitation of each lake is 1 gram of fish per
acre of water, meaning that in order to fulfill the adult ingestion
rate, a fisher would need to fish from 373 total acres of lakes. The
result of this analysis was the development of a site-specific emission
screening threshold for Hg2+. We compared this Tier II
screening threshold for Hg2+ to the facility's
Hg2+ emissions. The facility's emissions exceeded the Tier
II screening threshold by a factor of 3.
    Additionally, to refine our Hg Tier II Screen for this facility, we
first examined the set of lakes from which the angler ingested fish.
Any lakes that appeared to not be fishable or publicly accessible were
removed from the assessment, and the screening assessment was repeated.
After we made the determination the three critical lakes were fishable,
we analyzed the hourly meteorology data from which the Tier II
meteorology statistics were derived. Using buoyancy and momentum
equations from literature, and assumptions about facility fenceline
boundaries, we estimated by hour the height achieved by the emission
plume before it moved laterally beyond the assumed fenceline. If the
plume height was above the mixing height, we assumed there was no
chemical exposure for that hour. The cumulative loss of chemical being
released above the mixing height reduces the exposure and decreases the
Tier II screening quotient. Although the refined Tier II analysis for
Hg emissions indicated a 23-percent loss of emissions above the mixing
layer due to plume rise, this reduction still resulted in an angler
screening non-cancer value equal to 2.
    For this facility, after we performed the lake and plume rise
analyses, we reran the relevant Tier II screening scenarios for the
travelling subsistence angler in TRIM.FaTE with the same hourly
meteorology data and hourly plume-rise adjustments from which the Tier
II meteorology statistics were derived. The use of the time-series
meteorology reduced the screening value further to a value of 0.6. For
this source category our analysis indicated no potential for
multipathway impacts of concern from this facility. The maximum
facility-wide MIR was less than or equal to 1-in-1 million and the
maximum facility-wide TOSHI was 0.2. We weighed all health risk factors
in our risk acceptability determination, and we proposed that the
residual risks from the Phosphate Fertilizer Production source category
are acceptable.
    We then considered whether the Phosphate Fertilizer Production
NESHAP provides an ample margin of safety to protect public health and
prevents, taking into consideration costs, energy, safety, and other
relevant factors, an adverse environmental effect. In considering
whether the standards should be tightened to provide an ample margin of
safety to protect public health, we considered the same risk factors
that we considered for our acceptability determination and also
considered the costs, technological feasibility and other relevant
factors related to emissions control options that might reduce risk
associated with emissions from the source category. We proposed that
the current standards provided an ample margin of safety to protect
public health. With respect to adverse environmental effects, none of
the individual modeled concentrations for any facility in the source
category exceeded any of the ecological benchmarks (either the LOAEL or
NOAEL). Based on the results of our screening analysis for risks to the
environment, we also proposed that the current standards prevent an
adverse environmental effect.
2. How did the risk review change for the Phosphate Fertilizer
Production source category?
    The residual risk review for the Phosphate Fertilizer Production
source category did not change since proposal (79 FR 66512).
Accordingly, we are not tightening the standards under section
112(f)(2) based on the residual risk review, and are thus readopting
the existing standards under section 112(f)(2).
3. What key comments did we receive on the risk review, and what are
our responses?
    The comments received on the proposed residual risk review were
generally supportive of our determination of risk acceptability and
ample margin of safety analysis. However, we received several comments
requesting we make changes to the residual risk review, including:

     Update the residual risk review with the
recommendations and information from the NAS;
     Incorporate the best currently available information on
children's exposure to lead, and go beyond using the 2008 Lead
NAAQS;
     Reevaluate whether the residual risk review is
consistent with the key recommendations made by the SAB;
     Clarify in the rulemaking docket that data received by
industry were commensurate with the relevant statutory obligations;
     Revise HF emission data because they are not
representative of actual HF emissions, but rather overestimate
emissions causing the residual risk review to have an overly
conservative bias;
     Reconsider the assumption used in the NESHAP residual
risk assessment that all chromium is hexavalent chromium;
     Revise certain stack parameters used in the analysis;
     Clarify meteorological data used in the analysis;
     Adequately explain rationale for the maximum 1-hour
emission rate used for determining potential acute exposures;
     Clarify the selection of ecological assessment
endpoints; and
     Provide some quantitative or qualitative rationale for
the characterization of the exposure modeling uncertainty.

    We evaluated the comments and determined that no changes were
needed. Since none of these comments had an effect on the final rule,
their summaries and corresponding EPA responses are not included in
this preamble. A summary of these comments and our responses can be
found in the Comment Summary and Response document available in the
docket for this action (EPA-HQ-OAR-2012-0522).
4. What is the rationale for our final approach and final decisions for
the risk review?
    For the reasons explained in the proposed rule, we determined that
the risks from the Phosphate Fertilizer Production source category are
acceptable, the current emissions standards provide an ample margin of
safety to protect public health, and prevent an adverse environmental
effect. Since proposal, neither the risk assessment nor our
determinations regarding risk acceptability, ample margin of safety or
adverse environmental effects have changed. Therefore, pursuant to CAA
section 112(f)(2), we are finalizing our residual risk review as
proposed.

B. Technology Review for the Phosphate Fertilizer Production Source
Category

1. What did we propose pursuant to CAA section 112(d)(6) for the
Phosphate Fertilizer Production source category?
    Pursuant to CAA section 112(d)(6), we conducted a technology
review, which focused on identifying and evaluating developments in
practices, processes, and control technologies for the emission sources
in the Phosphate

Fertilizer Production source category. At proposal, we did not identify
cost-effective developments in practices, processes, or control
technologies that warrant revisions to the NESHAP for this source
category. More information concerning our technology review can be
found in the memorandum, ``CAA Section 111(b)(1)(B) and 112(d)(6)
Reviews for the Phosphate Fertilizer Production and Phosphate
Fertilizer Production Source Categories,'' which is available in the
docket, and in the preamble to the proposed rule, 79 FR 66538-66539.
2. How did the technology review change for the Phosphate Fertilizer
Production source category?
    The technology review for the Phosphate Fertilizer Production
source category did not change since proposal (79 FR 66512). Therefore,
we are not revising NESHAP subpart BB based on the technology review.
3. What key comments did we receive on the technology review, and what
are our responses?
    Commenters agreed with our conclusion that there are no new cost-
effective developments in practices, processes, or control technologies
that can be applied to the Phosphate Fertilizer Production source
category that would reduce HAP emissions below current levels.
4. What is the rationale for our final approach for the technology
review?
    For the reasons explained in the proposed rule, we concluded that
additional standards are not necessary pursuant to CAA section
112(d)(6); therefore, we are not finalizing changes to NESHAP subpart
BB as part of our technology review.

C. NSPS Review for the Phosphate Fertilizer Production Source Category

    The NSPS review focused on the emission limitations that have been
adequately demonstrated to be achieved in practice, taking into account
the cost of achieving such reduction and any non-air quality health and
environmental impact and energy requirements. Determining the BSER that
has been adequately demonstrated and the emission limitations achieved
in practice necessarily involves consideration of emission reduction
methods in use at existing phosphate fertilizer production plants. To
determine the BSER, the EPA performed an extensive review of several
recent sources of information including a thorough search of the RBLC,
section 114 data received from industry and other relevant sources.
    Our review considered the emission limitations that are currently
achieved in practice, and found that more stringent standards are not
achievable for this source category. When evaluating the emissions from
various process lines, we observed differences in emissions levels, but
did not identify any patterns in emission reductions based on control
technology configuration. More information concerning our NSPS review
can be found in the memorandum, ``CAA Section 111(b)(1)(B) and
112(d)(6) Reviews for the Phosphoric Acid Manufacturing and Phosphate
Fertilizer Production Source Categories.'' Though some of the sources
are emitting at levels well below the current NSPS, other sources are
not. We evaluated emissions based on control technologies and practices
used by facilities, and found that the same technologies and practices
yielded different results for different facilities. Therefore, we
determined that we cannot conclude that new and modified sources would
be able to achieve a more stringent NSPS. As explained in the proposed
rule, all Phosphate Fertilizer Production NSPS (under subpart V,
subpart W, and subpart X) emission sources, and the control
technologies that would be employed, are the same as those for the
NESHAP regulating phosphate fertilizer plants, such that we reached the
same conclusion that there are no identified developments in technology
or practices that results in cost-effective emission reductions
strategies. Therefore, we are finalizing our determination that
revisions to NSPS subpart V, subpart W, and subpart X standards are not
appropriate pursuant to CAA section 111(b)(1)(B).

D. Startup, Shutdown, and Malfunction Provisions for the Phosphate
Fertilizer Production Source Category

1. What SSM provisions did we propose for the Phosphate Fertilizer
Production source category?
    To address the U.S. Court of Appeals for the District of Columbia
Circuit vacatur of portions of the EPA's CAA section 112 regulations
governing the emissions of HAP during periods of SSM, Sierra Club v.
EPA, 551 F.3d 1019 (D.C. Cir. 2008), we proposed to revise and add
certain provisions to the NESHAP subpart BB. We proposed to revise the
General Provisions table (appendix A of NESHAP subpart BB) to change
several references related to requirements that apply during periods of
SSM. We also proposed to add the following provisions to the rule: (1)
Work practice standards for periods of startup and shutdown in lieu of
numeric emission limits; (2) the general duty to minimize emissions at
all times; (3) performance testing conditions requirements; (4) site-
specific monitoring plan requirements; and (5) malfunction
recordkeeping and reporting requirements. These proposed changes are
discussed in more detail in section V.E of this preamble where we
describe these same proposed changes for NESHAP subpart AA.
2. How did the SSM provisions change for the Phosphate Fertilizer
Production source category?
    We are finalizing the proposed work practice standards for periods
of startup and shutdown; however, in consideration of comments received
during the public comment period for the proposed rulemaking (as
discussed in sections VI.D.3.a and VI.D.3.b of this preamble), we are
making changes to this work practice in order to clarify the standard
applies in lieu of numeric emission limits and how compliance with the
standard is demonstrated. Additionally, as discussed in section
VI.D.3.c of this preamble, we added definitions of ``startup'' and
``shutdown'' to provide additional clarity regarding when startup
begins and ends, and when shutdown begins and ends.
3. What key comments did we receive on the SSM provisions, and what are
our responses?
    Comments were received regarding the proposed revisions to remove
the SSM exemptions for the Phosphate Fertilizer Production source
category, and the proposed work practice standards for periods of
startup and shutdown. The following is a summary of some of the
comments specific to the proposed work practice standards and our
response to those comments. Other comments and our specific responses
to those comments can be found in the Comment Summary and Response
document available in the docket for this action (EPA-HQ-OAR-2012-
0522).
    a. Work Practice Standard In Place Of Emission Limits--Comment. One
commenter argued that the EPA should specify that the proposed work
practices for plant startup and shutdown periods apply ``in lieu of''
any other emission standards, and that such periods should not be
counted for testing, monitoring, or operating parameter requirements.
The commenter noted that the proposed rule at 40 CFR 63.622(d) requires
the use of work practices ``to demonstrate compliance with any emission
limits''

during periods of startup and shutdown. The commenter agrees with the
EPA's conclusion that it is not feasible to apply numeric limits to
startup and shutdown because certain variables required to calculate
emissions would be zero during such periods. The commenter also agreed
with the EPA that existing emission control devices would still be
effective during periods of startup or shutdown, if activated. However,
the commenter recommended that the rule should clarify that startup and
shutdown events should not be required to comply with the monitoring
and operating parameter requirements because startup and shutdown
events generally are not representative operating conditions for other
compliance purposes, such as emissions testing. Instead, the commenter,
as well as a second commenter, recommended that because the startup and
shutdown periods are not representative, the rule should only require
that (1) All emission control devices be kept active, and (2) owners
and operators follow the general duty to control emissions, and owners
and operators should not be required to monitor operating parameters
during startup and shutdown periods.
    The commenter argued that the approach in the proposed rule at 40
CFR 63.622(d) to require the use of work practices ``to demonstrate
compliance with any emission limits'' during periods of startup and
shutdown is ``directly inconsistent'' with the approach that the EPA
has applied to other source categories, where such practices clearly
were prescribed ``in lieu of'' numeric emission limits that would
otherwise apply. (The commenter cites, for example, 78 FR 10015,
February 12, 2013.) According to the commenter, the EPA made it clear
in other industries' rules that such work practice standards apply ``in
place of'' or ``in lieu of'' numeric standards, including with respect
to monitoring and recordkeeping requirements. (See id. at 10013 and
10015.) The commenter argues that according to the preamble language
cited for those other industries, ``there will no longer be a numeric
emission standard applicable during startup and shutdown,'' and the EPA
recognizes that ``the recordkeeping requirement must change to reflect
the content of the work practice standard'' (Id. at 10014).
    Therefore, the commenter recommended that the EPA should clearly
explain that work practices are not applied to ``demonstrate
compliance'' with numeric limits under subpart BB, which the EPA
acknowledges are ``not feasible'' for startup and shutdown periods,
and, instead, the work practices should be written to apply ``in lieu
of'' the numeric limits during those periods. The commenter argues that
without this clarification, it will appear that both the numeric
standards and the work practice standards would apply during startup
and shutdown. The commenter suggests that this can be corrected in the
rule by using the ``in lieu of'' language used for other industries.
    Response. The commenter is correct that our intention at proposal
was that the numeric emission limits would not apply during periods of
startup and shutdown, but that facilities would comply with the work
practice instead. We did not intend for the work practice to be a
method to demonstrate compliance with the emission limit. We are
replacing the phrasing ``to demonstrate compliance'' with ``in lieu
of'' as this language is more consistent with our original intent.
Accordingly, in the final rule, 40 CFR 63.622(d) specifies that the
emission limits of 40 CFR 63.622(a) do not apply during periods of
startup and shutdown. Instead, owners and operators must follow the
work practice specified in 40 CFR 63.622(d). See section VI.D.3.b of
this preamble for our response to commenters argument that owners and
operators should not be required to monitor operating parameters during
startup and shutdown periods.
    b. Applicability of Operating Limits--Comment. Two commenters
recommended that the EPA amend the rule to make clear that the work
practice standards for startup and shutdown also apply in lieu of the
parametric monitoring requirements set forth in NESHAP subpart BB and
make explicit that parametric operating requirements do not apply
during times of startup and shutdown.
    One commenter argued that when the EPA established the flow rate
and pressure drop parametric monitoring requirements in its 1999 final
rule, the EPA concluded that requiring continuous monitoring of these
parameters ``help[ed] assure continuous compliance with the emission
limit'' (64 FR 31365, June 10, 1999). The commenter also asserted that
the rule specifies that ``[t]he emission limitations and operating
parameter requirements of this subpart do not apply during periods of
startup, shutdown, or malfunction . . . '' (40 CFR 63.620(e)). The
commenter argued that this was a reasonable action because the
operating parameter ranges are established during annual performance
tests, and these tests cannot be performed during startup and shutdown
conditions.
    The commenter suggested that in the proposed rule, the EPA exempted
compliance with the emission limits during startup and shutdown
periods, imposed work practice standards in lieu thereof, and retained
the prohibition on conducting a performance test during periods of
startup or shutdown (79 FR 66582 (proposed 40 CFR 63.626(d)). The
commenter suggested that the proposed rule is silent on the
applicability of the parametric monitoring requirements during startup
and shutdown. The commenter asserted that because the parametric
monitoring provisions provide an inference of compliance with the
emission limits (64 FR 31365, June 10, 1999), and these emission limits
do not apply during startup and shutdown, the commenter concluded that
the parametric monitoring provisions similarly should not apply during
startups and shutdowns.
    The commenters pointed to two recent EPA NESHAP rulemakings to
support their conclusion. First, the commenters argued that in its
industrial, commercial and institutional boilers and process heaters
NESHAP reconsideration proposal (hereinafter, the ``Boiler NESHAP''),
the EPA, responding to a comment soliciting clarification ``that the
operating limits and opacity limits do not apply during periods of
startup and shutdown,'' stated that with the finalization of work
practice standards, ``EPA agrees that the requested clarification is
what was intended in the final rule'' (76 FR 80598 and 80615, December
23, 2011.) The commenters asserted that to this end, in its response to
the reconsideration, the EPA made clear that affected sources must
comply with ``all applicable emissions and operating limits at all
times the unit is operating except for periods that meet the
definitions of startup and shutdown in this subpart, during which times
you must comply with these work practices'' (78 FR 7138 and 7142,
January 31, 2013.) The commenters noted that in the Boiler NESHAP, the
EPA required the implementation of work practice standards in lieu of
compliance with the operating parameter requirements during startup and
shutdown by (1) Excluding periods of startup and shutdown from the
averaging period (Id. at 7187, 40 CFR 63.7575, the definition of a 30-
day rolling average'' excludes ``hours during startup and shutdown''),
and (2) expressly stating that the ``standards'' (the emission limits
and operating requirements) do not apply during periods of startup or
shutdown. (Id. at 7163, 40 CFR 63.7500(f), titled ``What emission
limitations, work

practice standards, and operating limits must I meet?'' applies ``at
all times the affected unit is operating, except during periods of
startup and shutdown during which time you must comply only with Table
3 of this subpart'').
    Second, the commenters argued that in its Portland Cement NESHAP,
the EPA specified an operating limit for kilns, identified as a
temperature limit established during a performance test, and that the
temperature limit applied at all times the raw mill is operating,
``except during periods of startup and shutdown'' (78 FR 10039,
February 12, 2013, 40 CFR 63.1346(a)(1).) Further, for the continuous
monitoring requirements, including operating limits, the Portland
Cement NESHAP required operating of the monitoring system at all times
the affected source is operating, ``[e]xcept for periods of startup and
shutdown'' (Id. at 10041, 40 CFR 63.1348(b)(1)(ii).)
    The commenters argued that given the EPA's conclusion in the
Proposed Rule that the emission limits should not apply during startup
and shutdown, and because the parametric monitoring requirements are
established during a performance test (which cannot be performed during
a startup or a shutdown) and used to infer compliance with the emission
limits, the EPA should make clear in the final rule that the operating
parameters requirements do not apply during a startup or a shutdown.
The commenter recommended that the EPA should make this explicit: (1)
In the operating and monitoring requirement section of subpart BB
(proposed 40 CFR 63.625), and (2) by defining the averaging period
(currently daily) as excluding periods of startup and shutdown
(Proposed 40 CFR part 63, subpart BB, Table 4). As an alternative, the
commenters recommended that if the EPA continues to require compliance
with the parametric monitoring requirements during startup and shutdown
periods, then the EPA should adopt a longer averaging period, from
daily to 30 days, to allow for the effects of startups and shutdowns to
be reduced by a longer period of steady-state operations. The commenter
noted that the Boiler NESHAP has a 30-day averaging period for pressure
drop and liquid flow rate, and excludes periods of startup and shutdown
from the averaging period (40 CFR 63.7575, definition of ``30-day
rolling average'' and 40 CFR part 63, subpart DDDDD, Table 4). The
commenter stated that a 30-day averaging period would be substantially
more stringent than the Boiler NESHAP approach since it would include
periods of startup and shutdown, while at the same time avoid
misleading ``exceedances'' caused by the inclusion of periods of
startup and shutdown compared to daily average parametric limits.
    Response. We disagree with the commenters about the applicability
of the operating limits. Based on these comments, we have clarified in
the final rule at 40 CFR 63.622(d) that to comply with the work
practice during periods of startup and shutdown, facilities must
monitor the operating parameters specified in Table 3 to subpart BB and
comply with the operating limits specified in Table 4 of subpart BB.
The purpose of the work practice is to ensure that the air pollution
control equipment that is used to comply with the emission limit during
normal operations is operated during periods of startup and shutdown.
Monitoring of control device operating parameters is necessary to
demonstrate compliance with the work practice. We have concluded that
it is reasonable for the control device at phosphate fertilizer
production processes to meet the same operating limits during startup
and shutdown that apply during normal operation, and that it is not
necessary to specify different averaging times for periods of startup
and shutdown. Meeting the operating limits of Table 4 of subpart BB
will ensure that owners and operators meet the General Duty requirement
to operate and maintain the affected source and associated air
pollution control equipment in a manner consistent with safety and good
air pollution control practices for minimizing emissions.
    The analogies that the commenters made to the Boiler NESHAP and the
Portland Cement NESHAP are not relevant to this rulemaking. In each
rulemaking, we consider the feasibility of applying standards during
startup and shutdown based on relevant process considerations for each
source category, the pollutants regulated, and control devices on which
the rule is based. In developing this rule, we obtained information on
the operation of control devices during startup and shutdown periods in
the CAA section 114 survey issued to the phosphate fertilizer
production industry. Based on survey results, we concluded that for
this source category, control devices (i.e., absorbers) could be
operated during periods of startup and shutdown. We found no indication
that process operations during startup and shutdown would interfere
with the ability to operate the relevant control devices according to
good engineering practice. Moreover, the commenters provided no
technical justification as to why a different operating limit is needed
during startup and shutdown.
    Regarding the comparison to the industrial boiler NESHAP, the
operation of boilers and their associated control devices are different
than phosphate fertilizer production plants. While boiler control
devices do not have to comply with specific operating limits during
startup or shutdown, they must meet a work practice that includes
firing clean fuels, operating relevant control devices (e.g.,
absorbers) as expeditiously as possible, and monitoring the applicable
operating parameters (e.g., flow rate) to demonstrate that the control
devices are being operated properly. The EPA currently is reconsidering
the control requirements for industrial boilers during startup and
shutdown (80 FR 3090, January 21, 2015). In the proposed action on
reconsideration, we pointed out that some of the control devices used
for boilers cannot be operated during the full duration of startup and
shutdown because of safety concerns and the possibility of control
equipment degradation due to fouling and corrosion. The control devices
used for phosphate fertilizer production do not pose these same risks.
Likewise, the fact that the Portland Cement NESHAP does not require
monitoring of kiln temperature during startup and shutdown is not
relevant. The Portland Cement NESHAP requires maintaining a kiln
temperature as part of the MACT operating limit. The operating limit
for Portland Cement does not apply during startup and shutdown because
it is not physically possible to maintain a constant temperature during
startup and shutdown of a kiln. In contrast, the feasibility of
operating the control devices used to control HAP emissions from
phosphate fertilizer production is not limited by specific process
operating conditions. Therefore, it is feasible to operate the devices
during startup and shutdown, and we have determined that it is
reasonable to do so considering cost, nonair health and environmental
impacts, and energy requirements.
    c. Definition of Startup and Shutdown--Comment. Several commenters
stated that it is not feasible to base the conclusion of a ``shutdown''
on the point at which all feed has ``been processed.'' Instead, they
suggested that the EPA should clarify the work practice standard of
keeping all emission control equipment active during shutdowns. The
commenters reported that facilities in the industry consider the
commencement of ``shutdown'' as the moment at which the plant ceases
adding feed to the affected process, rather than basing shutdown on
when

all feed materials have been processed through the process. The
commenters recommended that the EPA should define ``shutdown'' to begin
when the facility ceases adding feed to an affected process line, and
to conclude when the affected process line equipment is deactivated,
even though some feed or residues may still be present within
particular parts of the process.
    One of the commenters also noted that it is common practice to have
short-term shutdown of process inputs for temporary maintenance work
(including work on emission control equipment) where the entire system
is not emptied. In these cases, feed of phosphoric acid and ammonia to
the process is suspended as is flow from the reactor to the granulator.
The commenter argued that because the source of fluoride to the system
has ceased and dust generating material flows are suspended, there
should be no significant source of emissions to control, and it is not
necessary to require the utilization of control devices until all feed
material has been processed. Instead, the commenter recommended that an
affected entity should be allowed to turn off control devices when
reactor and granulator feeds have been stopped, unless the system is
being emptied, in which case control devices should be required as long
as the material handling system is in operation.
    Response. We agree with the commenters that the rule needs to have
a more precise definition of startup and shutdown that more clearly and
reasonably establishes the times when the work practice applies and
when the emission limits apply. Accordingly, we added a definition of
``startup'' and ``shutdown'' in the Definitions section of the final
rule to specify when startup begins and ends, and when shutdown begins
and ends.
    Based on additional information provided by industry (see ``Email
Correspondence Received After Comment Period re Startup Shutdown (May
5, 2015),'' which is available in Docket ID No. EPA-HQ-OAR-2012-0522),
we are including a definition of startup in the final rule. The final
rule defines startup as commencing when any feed material is first
introduced into an affected source and ends when feed material is fully
loaded into the affected source. Regarding shutdown, we agree with the
commenters that it is not feasible to process all feed material from a
process prior to shutting down most equipment at a facility. Such
requirement would imply that the control device must be operated after
the shutdown ends. The final rule defines shutdown as commencing when
the facility ceases adding feed to an affected source and ends when the
affected source is deactivated, regardless of whether feed material is
present in the affected source. This definition will address concerns
about temporary shutdowns as well as shutdowns of longer duration.
    In addition, the final rule at 40 CFR 63.622(d) specifies that any
control device used at the affected source must be operated during the
entire period of startup and shutdown, and must meet the operating
limits in Table 4 of the rule.
4. What is the rationale for our final decisions for the SSM
provisions?
    For the reasons provided above and in the preamble for the proposed
rule, we are finalizing the proposed revisions to the General
Provisions table (appendix A of NESHAP subpart BB) to change several
references related to requirements that apply during periods of SSM.
For these same reasons, we are also finalizing the addition of the
following proposed provisions to NESHAP subpart BB: (1) Work practice
standards for periods of startup and shutdown in lieu of numeric
emission limits; (2) the general duty to minimize emissions at all
times; (3) performance testing conditions requirements; (4) site-
specific monitoring plan requirements; and (5) malfunction
recordkeeping and reporting requirements.

E. Other Changes Made to the Phosphate Fertilizer Production NESHAP and
NSPS

1. What other changes did we propose for the Phosphate Fertilizer
Production NESHAP and NSPS?
    a. Clarifications to Applicability and Certain Definitions --i.
NESHAP Subpart BB. As stated in the preamble to the proposed rule, to
ensure the emission standards reflect inclusion of HAP emissions from
all sources in the source category, we proposed to clarify the
applicability of the NESHAP to include reaction products of ammonia and
phosphoric acid, and not just diammonium and monoammonium phosphate.
    For consistency between NESHAP subpart AA and NESHAP subpart BB, we
also proposed conditions in NESHAP subpart BB that exclude (like NESHAP
subpart AA does) the use of evaporative cooling towers for any liquid
effluent from any wet scrubbing device installed to control HF
emissions from process equipment. Lastly, we proposed to amend the
definitions of ``diammonium and/or monoammonium phosphate process
line,'' ``granular triple superphosphate process line,'' and ``granular
triple superphosphate storage building'' to include relevant emission
points, and to remove text from the applicability section that is
duplicative of the revised definitions.
    ii. NSPS Subpart V. We did not propose changes to applicability or
definitions in NSPS subpart V.
    iii. NSPS Subpart W. We proposed changing the word ``cookers'' as
listed in 40 CFR 60.230(a) to ``coolers'' in order to correct the
typographical error.
    iv. NSPS Subpart X. We did not propose changes to applicability or
definitions in NSPS subpart X.
    b. Testing, Monitoring, Recordkeeping and Reporting--i. NESHAP
Subpart BB. As stated in the preamble to the proposed rule, to provide
flexibility, we proposed several monitoring options, including pressure
and temperature measurements, as alternatives to monitoring of absorber
differential pressure. We also proposed monitoring the absorber inlet
gas flow rate along with the influent absorber liquid flow rate (and
determining liquid-to-gas ratio) in lieu of monitoring only the
absorber inlet liquid flow rate.
    In addition, we proposed removing the requirement that facilities
may not implement new operating parameter ranges until the
Administrator has approved them, or 30 days have passed since
submission of the performance test results. We proposed that facilities
must immediately comply with new operating ranges when they are
developed and submitted; and new operating ranges must be established
using the most recent performance test conducted by a facility, which
allows for changes in control device operation to be appropriately
reflected.
    We also proposed monitoring requirements for fabric filters in
NESHAP subpart BB because we identified two processes that used fabric
filters rather than wet scrubbing as control technology.
    As stated in the preamble to the proposed rule, we modified the
language for the conditions under which testing must be conducted to
require that testing be conducted at ``maximum representative operating
conditions'' for the process.\11\
---------------------------------------------------------------------------

    \11\ Based on the EPA memorandum, ``Issuance of the Clean Air
Act National Stack Testing Guidance,'' dated April 27, 2009.
---------------------------------------------------------------------------

    In keeping with the general provisions for CMS (including CEMS and
CPMS), we proposed the addition of a site-specific monitoring plan and
calibration requirements for CMS. Provisions were also proposed that
included electronic reporting of stack test data. We also

proposed modifying the format of NESHAP subpart BB to reference tables
for emissions limits and monitoring requirements.
    Finally, we proposed HF standards in NESHAP subpart BB by
translating the current total fluoride limits (lb total F/ton
P2O5 feed) into HF limits (lb HF/ton
P2O5 feed). To comply with HF standards, we
proposed that facilities use EPA Method 320.
    ii. NSPS Subpart V. We proposed new monitoring and recordkeeping
requirements for any granular diammonium phosphate plant that commences
construction, modification or reconstruction after November 7, 2014 to
ensure continuous compliance with the standard. As stated in the
preamble to the proposed rule, to ensure that the process scrubbing
system is properly maintained over time; ensure continuous compliance
with standards; and improve data accessibility, we proposed the owner
or operator establish an allowable range for the pressure drop through
the process scrubbing system. We also proposed that the owner or
operator keep records of the daily average pressure drop through the
process scrubbing system, and keep records of deviations.
    For consistency with terminology used in the associated NESHAP
subpart BB, we proposed changing the term ``scrubbing system'' to
``absorber'' in NSPS subpart V.
    iii. NSPS Subpart W. We proposed new monitoring and recordkeeping
requirements for any TSP plant that commences construction,
modification or reconstruction after November 7, 2014 to ensure
continuous compliance with the standard. As stated in the preamble to
the proposed rule, to ensure that the process scrubbing system is
properly maintained over time; ensure continuous compliance with
standards; and improve data accessibility, we proposed the owner or
operator establish an allowable range for the pressure drop through the
process scrubbing system. We also proposed that the owner or operator
keep records of the daily average pressure drop through the process
scrubbing system, and keep records of deviations.
    For consistency with terminology used in the associated NESHAP
subpart BB, we proposed changing the term ``process scrubbing system''
to ``absorber'' in NSPS subpart W.
    iv. NSPS Subpart X. We proposed new monitoring and recordkeeping
requirements for any GTSP storage facility that commences construction,
modification or reconstruction after November 7, 2014 to ensure
continuous compliance with the standard. As stated in the preamble to
the proposed rule, to ensure that the process scrubbing system is
properly maintained over time; ensure continuous compliance with
standards; and improve data accessibility, we proposed the owner or
operator establish an allowable range for the pressure drop through the
process scrubbing system. We also proposed that the owner or operator
keep records of the daily average pressure drop through the process
scrubbing system, and keep records of deviations.
    For consistency with terminology used in the associated NESHAP
subpart BB, we proposed changing the term ``process scrubbing system''
to ``absorber'' in NSPS subpart X.
2. How did the provisions regarding these other proposed changes to the
Phosphate Fertilizer Production NESHAP and NSPS change since proposal?
    a. Clarifications to Applicability and Certain Definitions--i.
NESHAP Subpart BB. In consideration of comments received during the
public comment period for the proposed rulemaking, we are defining
``phosphate fertilizer process line'' and ``phosphate fertilizer
production plant'' separately as discussed in section VI.E.3.a.i of
this preamble. We are also revising rule language at 40 CFR
63.620(b)(1), 63.622(a), 63.622(a)(1), 63.622(a)(2), 63.625(a),
63.626(f), in Table 1, and in Table 2 to accommodate this change. We
are also removing the proposed language ``includes, but is not limited
to'' in the definition of DAP and/or MAP process line for reasons
discussed in section VI.E.3.a.ii of this preamble.
    ii. NSPS Subpart V. We are not making changes to applicability or
definitions in NSPS subpart V.
    iii. NSPS Subpart W. We are not making changes to applicability or
definitions in NSPS subpart W.
    iv. NSPS Subpart X. We are not making changes to applicability or
definitions in NSPS subpart X.
    b. Testing, Monitoring, Recordkeeping and Reporting.--i. NESHAP
Subpart BB. We have not made any changes to our proposed determination
that pressure drop is not an appropriate monitoring parameter for
absorbers that are designed to operate with pressure drops of 5 inches
of water column or less. However, in consideration of comments received
during the public comment period for the proposed rulemaking, we are
not adopting the proposed options to monitor: (1) The temperature at
the wet scrubber gas stream outlet and pressure at the liquid inlet of
the absorber, or (2) the temperature at the scrubber gas stream outlet
and scrubber gas stream inlet. Instead, we have revised Table 3 of
NESHAP subpart BB to require liquid-to-gas ratio monitoring for low-
energy absorbers, and influent liquid flow and pressure drop monitoring
for high-energy absorbers; and we are keeping liquid-to-gas ratio
monitoring as an option for high-energy absorbers in the final rule.
(See sections VI.E.3.b.i and VI.E.3.b.ii of this preamble for details.)
    In addition to these revisions, we are making corrections at 40 CFR
63.627(a) to clarify the procedures for establishing a new operating
limit based on the most recent performance test. We are also revising
the requirements at 40 CFR 63.625(d)(1)(ii)(B) to remove the
requirement that facilities must request and obtain approval of the
Administrator for changing operating limits. (See section VI.E.3.b.iv
and VI.E.3.b.v of this preamble for details.)
    Also, for reasons discussed in the Comment Summary and Response
document available in the docket, we are revising the annual testing
schedule in the final rule at 40 CFR 63.626(b), and the terminology for
``maximum representative operating conditions'' in the final rule at 40
CFR 63.626(d).
    We are not making any changes to the proposed addition of a site-
specific monitoring plan and calibration requirements for CMS. We are
also keeping the proposed term ``absorber'' in lieu of ``scrubber,'' as
well as the proposed format of NESHAP subpart BB to reference tables
for emissions limits and monitoring requirements.
    Lastly, we are retaining the current total fluoride limits and not
adopting the proposed HF standards and associated EPA Method 320
testing in NESHAP subpart BB (see section VI.E.3.c of this preamble for
details).
    ii. NSPS Subpart V. We are not making changes to the proposed
monitoring and recordkeeping requirements for any granular diammonium
phosphate plant that commences construction, modification or
reconstruction after August 19, 2015 to ensure continuous compliance
with the standard. We are also keeping the proposed term ``absorber''
in lieu of ``scrubbing system.''
    iii. NSPS Subpart W. We are not making changes to the proposed
monitoring and recordkeeping requirements for any TSP plant that
commences construction, modification or reconstruction after August 19,
2015 to ensure continuous compliance with the standard. We are also
keeping the proposed term ``absorber'' in lieu of ``process scrubbing
system.''
    iv. NSPS Subpart X. We are not making changes to the proposed

monitoring and recordkeeping requirements for any GTSP storage facility
that commences construction, modification or reconstruction after
August 19, 2015 to ensure continuous compliance with the standard. We
are also keeping the proposed term ``absorber'' in lieu of ``process
scrubbing system.''
3. What key comments did we receive on the other changes to the
Phosphate Fertilizer Production NESHAP and NSPS, and what are our
responses?
    Several comments were received regarding the proposed
clarifications to applicability and certain definitions, revisions to
testing, monitoring, recordkeeping and reporting, translation of total
fluoride to HF emission limits, and revisions to other provisions for
the Phosphate Fertilizer Production source category. The following is a
summary of several of these comments and our response to those
comments. Other comments received and our responses to those comments
can be found in the Comment Summary and Response document available in
the docket for this action (EPA-HQ-OAR-2012-0522).
    a. Applicability Clarifications and Certain Definitions--i.
Phosphate Fertilizer Process Line--Comment. Several commenters
disapproved of the proposed expansion of the applicability provision
for DAP and MAP process lines in 40 CFR 63.620(b)(1) to include ``any
process line that produces a reaction product of ammonia and phosphoric
acid.'' One commenter asserted that the expanded language could include
production of non-granular products that were in existence since the
original NESHAP but not regulated by it, and EPA provided no basis for
expansion of applicability to bring in these processes now. Other
commenters also reiterated that the proposed applicability provision
for DAP and MAP process lines was vague and overbroad and would
inadvertently regulate any process that combines ammonia and phosphoric
acid regardless of the end-product or purpose of facility. One
commenter recommended a change in the definition to clarify that
subpart BB applies specifically to solid, granulated phosphate products
to avoid inclusion of liquid fertilizer products in the proposed rule.
    Response. The Agency agrees with the commenter that the proposed
language could be interpreted to include production of non-granular
products at a phosphate fertilizer production plant. It was not our
intent to expand the applicability of 40 CFR subpart BB to include the
production of non-granular products at a phosphate fertilizer
production plant; therefore, we are revising the definitions of
``phosphate fertilizer process line'' and ``phosphate fertilizer
production plant'' in the final rule at 40 CFR 63.621 to reference
granular phosphate fertilizer. Also, the definitions of phosphate
fertilizer process line and phosphate fertilizer production plant were
defined together at proposal (phosphate fertilizer process line or
production plant), but are defined separately in the final rule for
clarity. The definition of phosphate fertilizer process line means
``any process line that manufactures a granular phosphate fertilizer by
reacting phosphoric acid with ammonia. A phosphate fertilizer process
line includes: Reactors, granulators, dryers, coolers, screens, and
mills.'' The definition of phosphate fertilizer production plant means
``any production plant that manufactures a granular phosphate
fertilizer by reacting phosphoric acid with ammonia.''
    As an outgrowth of this comment, the Agency revised rule language
surrounding the use of ``phosphate fertilizer process line,'' to create
clarity and consistency in rule language. Specifically, where the
phrase ``diammonium and/or monoammonium phosphate process line and any
process line that produces a reaction product of ammonia and phosphoric
acid'' was used at proposal, this phrase now reads ``phosphate
fertilizer process line (e.g., diammonium and/or monoammonium phosphate
process line)'' in the finalized rule. This phrasing was incorporated
into final rule language at 40 CFR 63.620(b)(1), 63.622(a),
63.622(a)(1), 63.622(a)(2), 63.625(a), 63.626(f), in Table 1, and in
Table 2.
    ii. ``Includes, but is Not Limited to''--Comment. A commenter
remarked that incorporating the language ``includes, but is not limited
to'' in the definition of DAP and/or MAP process line is overly broad
and creates ambiguity. They stated that industry should have certainty
as to the applicability and scope of the rule, but the language
``includes, but is not limited to'' creates uncertainty as to where the
affected equipment begins and ends for purposes of demonstrating
compliance.
    Response. We agree that this language creates overly broad process
line definitions and can lead to regulatory uncertainty for affected
sources. Therefore, we are not finalizing the language ``includes, but
is not limited to'' in the definition of DAP and/or MAP process line.
    b. Testing, Monitoring, Recordkeeping and Reporting--i. Pressure
Drop Across Absorber--Comment. Several commenters requested the EPA
delete the requirement that pressure drop across an absorber must be
greater than 5 inches of water in order to use the option of measuring
pressure drop as an operating parameter. These commenters contended
that the EPA has not articulated any basis for the requirement. These
commenters provided data demonstrating that units operate in compliance
with the emission standards when the pressure drop across an absorber
is less than 5 inches of water. One of these commenters expressed
safety concerns associated with operating scrubbers at higher range
pressure drop settings, citing that one of its facilities has
experienced the entrainment of moisture within the absorbing tower when
operating at pressure drops in excess of 8 inches of water, and another
has experienced the buildup of excessive fumes on the digester floor
when operating the digester scrubber as high as 6 inches of water.
    Response. The Agency maintains its determination that pressure drop
is not an appropriate monitoring parameter for absorbers that do not
use the energy from the inlet gas to increase contact between the gas
and liquid in the absorber (see ``Use of Pressure Drop as an Operating
Parameter,'' which is available in Docket ID No. EPA-HQ-OAR-2012-0522).
Therefore, we are not revising this proposed amendment. For further
explanation please see our response to the identical comment that was
made for NESHAP subpart AA in section V.F.3.b.i of this preamble.
    ii. Absorber Monitoring Options--Comment. Several commenters called
attention to the options of either measuring: (1) The temperature at
the wet scrubber gas stream outlet and pressure at the liquid inlet of
the absorber, or (2) the temperature at the scrubber gas stream outlet
and scrubber gas stream inlet. One of these commenters said that they
do not believe monitoring gas temperature in locations of large ambient
temperature ranges would provide accurate monitoring of the absorbers
performance. The commenter argued that temperature and pressure probes
would be very susceptible to scaling issues. In addition, this
commenter contended that liquid inlet pressure does not provide any
additional monitoring of the absorber performance, since the inlet
liquid flow rate is already measured and monitored. Another commenter
contended that the EPA has not provided any data or analysis to show
that there is a correlation between temperature and emissions; the
commenter stated that they were not

aware of any data suggesting a relationship between exit temperature
and emissions, or that monitoring temperature difference across an
absorber would be effective. One of these commenters argued that they
were not in a position to evaluate the difficulties associated with
performing the associated monitoring and establishing the requisite
operating ranges.
    Response. Absorber outlet gas temperature is often used to indicate
a change in operation for absorbers used to control thermal processes.
Because this source category does not use a thermal process to produce
fertilizer, the Agency agrees with the commenters that temperature is
not an appropriate monitoring parameter for absorbers used in this
source category, and has removed these monitoring options from Table 3
of the final rule (NESHAP subpart BB). However, in light of this
comment, the Agency has revised Table 3 of NESHAP subpart BB to require
liquid-to-gas ratio monitoring for low-energy absorbers (i.e.,
absorbers that are designed to operate with pressure drops of 5 inches
of water column or less) in lieu of monitoring influent liquid flow and
pressure drop through the absorber. Furthermore, the Agency has revised
Table 3 of NESHAP subpart BB to require influent liquid flow and
pressure drop monitoring for high-energy (i.e., high pressure drop)
absorbers, such as venturi scrubbers; and we are keeping liquid-to-gas
ratio monitoring as an option for high-energy absorbers in the final
rule. For further explanation please see our response to the identical
comment that was made for NESHAP subpart AA in section V.F.3.b.ii of
this preamble.
    iii. Acceptable Range From Baseline Average Value--Comment. One
commenter requested that the EPA revise 40 CFR 63.625(d)(1)(ii)(B) to
have similar wording to 40 CFR 63.625(d)(1)(ii)(A), in which the
allowable parametric limits may encompass up to +/-20 percent of the of
the baseline average values for the series of tests used under this
option; that is, the parametric limit may extend -20 percent below the
lowest baseline average and up to +20 percent above the highest
baseline average from the series of performance tests used for this
option.
    Response. The Agency determined that it is not necessary to revise
40 CFR 63.625(d)(1)(ii)(B) to allow for a 20 percent
operating margin, as this commenter requests, because this provision
already allows owners or operators to establish an operating limit
range for a control device without having to apply an operating margin,
such as 20 percent. Owners or operators that use an
absorber or a WESP to comply with the emission limits (and monitor
pressure drop across each absorber or secondary voltage for a WESP)
have two options to establish operating limits for demonstrating
continuous compliance: (1) At 40 CFR 63.625(d)(1)(ii)(A), the operating
limits may be determined using the most recent performance test and
applying an operating margin of 20 percent (e.g., during
the three test runs conducted for an owner's or operator's most recent
performance test that demonstrated compliance with the emission limit,
the arithmetic average of the absorber pressure drops recorded was 7
inches of water; therefore, under this option, the owner's or
operator's operating limit range for this absorber would be 5.6 to 8.4
inches of water, or 20 percent of 7); or (2) at 40 CFR
63.625(d)(1)(ii)(B), owners or operators may establish operating limit
ranges based upon baseline values of operating parameters established
in either historic performance tests or performance tests conducted
specifically to establish such ranges (e.g., an owner or operator could
choose to conduct two consecutive performance tests consisting of three
test runs each and if the owner or operator demonstrates compliance
with the emission limit while operating an absorber with a pressure
drop of 6 inches of water during the first performance test, and then
in the second performance test the owner or operator demonstrates
compliance with the emission limit while operating an absorber with a
pressure drop of 10 inches of water, the owner's or operator's
operating limit range for this absorber would be 6 to 10 inches of
water under this option). Additionally, the rule permits owners or
operators to undertake additional performance testing (for either
option) to establish control device operating limits which reflect
compliance with the emission limit for the full range of operating
conditions of the control device. Therefore, the Agency has determined
that no change to 40 CFR 63.625(d)(1)(ii)(B) is warranted.
    iv. Operating Range Established From a Previous Test--Comment. One
commenter stated that 40 CFR 63.627(a) is somewhat ambiguous, tending
to suggest that affected facilities would be immediately required to
implement new equipment operating ranges following a source test, even
if operating conditions from previous source tests demonstrated
compliance with fluoride emission standards. The commenter argued that
there is no reason that a new performance test at a new operating range
should invalidate a previous performance test at a different operating
range.
    Response. The Agency has clarified in the final rule at 40 CFR
63.627(a) that during the most recent performance test, if owners or
operators demonstrate compliance with the emission limit while
operating their control device outside the previously established
operating limit, then limits must be established. Owners or operators
must establish a new operating limit based on that most recent
performance test and notify the Administrator that the operating limit
changed based on data collected during the most recent performance
test. For further explanation please see our response to the identical
comment that was made for NESHAP subpart AA in section V.F.3.b.iii of
this preamble.
    v. Approving Operating Ranges--Comment. Several commenters support
the EPA's proposal to eliminate the requirement that facilities may not
implement new operating parameter ranges until the Administrator has
approved them, or 30 days have passed since submission of the
performance test results. However, two of these commenters pointed out
that the EPA did not make the same allowance in 40 CFR
63.625(d)(1)(ii)(B), where a series of tests (potentially including
historical tests) are used to establish an operating range. A commenter
pointed out that 40 CFR 63.625(d)(1)(ii)(B), as proposed, does not
provide the 30-day default period for the effectiveness of the new
ranges if the EPA Administrator does not act; therefore, as currently
set forth in the proposed rule, sources will be left in limbo waiting
for the EPA Administrator to respond before they can implement new
ranges. A commenter suggested that the EPA revise the proposed
regulatory language to require submission of the new ranges to EPA, but
delete the requirement to request and obtain EPA's approval of the new
ranges. Similarly, another commenter requested the EPA clarify the
process for establishing new equipment operating ranges following
source performance testing. This commenter contended that facilities
should have the ability to update operating parameters if they desire
based on source testing, and the facility should be required to submit
the new ranges, but not be required to obtain EPA's approval of the new
ranges.
    In addition, a commenter requested that the EPA clarify how
revising the proposed regulatory language to require submission of the
new ranges to the

EPA, but deleting the requirement to request and obtain EPA's approval
of the new ranges, will affect possible obligations to undertake permit
modifications of title V permits under 40 CFR part 70. This commenter
stated that such administrative processes are not fully anticipated in
the proposed rule.
    Response. In the proposed NESHAP subpart BB, the Agency intended
that facilities not be required to obtain approval, and instead,
immediately comply with a new operating limit when it is developed and
submitted to the Administrator. Therefore, the requirements at 40 CFR
63.625(d)(1)(ii)(B) have been revised in the final rule, as the
commenter requests, to remove the requirement that facilities must
request and obtain approval of the Administrator for changing operating
limits. Furthermore, the Agency suggests that the title V permit be
modified as soon as the Administrator is notified of a change in an
operating limit. The Agency acknowledges that corrections and
modifications to permit applications could become a problem for a
facility, particularly if the Administrator determines the operating
limit is not appropriate after a facility has already applied for the
change to be made in their air permit; however, we expect this scenario
to be rare.
    c. Translation of Total Fluoride to HF Emission Limits--Comment.
Several commenters expressed concerns regarding the methodology for
expressing the existing total fluoride limits in terms of HF (refer to
section V.F.3.c of this preamble for a summary of comments received on
this topic).
    Response. In light of information provided by commenters, the
Agency has re-evaluated the proposed revision to the standard and
determined that EPA Method 320 is not an appropriate test method for
accurately measuring HF emissions from process lines at this specific
source category due to the complex and often incomplete chemical
reactions with silicon compounds in these sources. Accordingly, we are
not adopting the proposed HF standards, and instead we are retaining
the existing total fluoride limits for all emission sources in subpart
BB. For further explanation on this determination, refer to section
V.F.3.c of this preamble. Although, at the present time, the Agency is
not finalizing HF standards in NESHAP subpart BB, it may be possible to
do so in a future rulemaking with additional data and specificity on
monitoring requirements.
4. What is the rationale for our final decisions regarding these other
changes to the Phosphate Fertilizer Production NESHAP and NSPS?
    For the reasons provided above and in the preamble for the proposed
rule, we are finalizing the proposed requirement in NESHAP subpart BB
that pressure drop across an absorber must be greater than 5 inches of
water in order to use the option of measuring pressure drop as an
operating parameter; and other proposed clarifications and corrections.
    Additionally, for the reasons provided above, we are making the
revisions, clarifications and corrections noted in section VI.E.2 in
the final rules for NESHAP subpart BB, NSPS subpart V, NSPS subpart W,
and NSPS subpart X.

VII. Summary of Cost, Environmental, and Economic Impacts and
Additional Analyses Conducted

A. What are the affected facilities?

    We anticipate that the 13 facilities currently operating in the
U.S. will be affected by these amendments. We do not expect any new
facilities to be constructed or expanded in the foreseeable future.

B. What are the air quality impacts?

    We anticipate HF emissions reductions as a result of one facility
installing controls on its oxidation reactor to comply with the SPA
total fluoride limit. However, we do not have emissions data for its
oxidation reactor to calculate these reductions. In addition, the
revised rule will mitigate future increases of Hg emissions from
phosphate rock calciners by requiring compliance with numeric emission
limits.

C. What are the cost impacts?

    We have estimated compliance costs for all existing sources to add
the necessary controls and monitoring devices, perform inspections, and
implement recordkeeping and reporting requirements to comply with the
final rules. Based on this analysis, we anticipate an overall total
capital investment of $346,000, with an associated total annualized
cost of approximately $294,000. We do not anticipate the construction
of any new phosphoric acid manufacturing plants or phosphate fertilizer
production facilities in the next 5 years. Therefore, there are no
anticipated new source cost impacts. We estimated the cost to install a
venturi scrubber to meet the SPA process line total fluoride standard,
when oxidation reactor emissions are included, for one facility. For
all emission sources, we calculated capital and annual costs for
testing, monitoring, recordkeeping, and reporting. The memorandum,
``Control Costs and Emissions Reductions for Phosphoric Acid and
Phosphate Fertilizer Production Source Categories--Final Rule,'' which
is available in the docket for this action, documents the control cost
analyses.

D. What are the economic impacts?

    Economic impact analyses focus on changes in market prices and
output levels. If changes in market prices and output levels in the
primary markets are significant, we also examine impacts on other
markets. Both the magnitude of costs needed to comply with the rule and
the distribution of these costs among affected facilities can have a
role in determining how the market will change in response to the rule.
We project that no facility will incur significant costs.
    Because no small firms will incur control costs, there is no
significant impact on small entities. Thus, we do not expect this
regulation to have a significant impact on a substantial number of
small entities.

E. What are the benefits?

    The revised rule will mitigate future increases of Hg emissions
from phosphate rock calciners by requiring compliance with numeric
emission limits. These avoided emissions will result in improvements in
air quality and reduced negative health effects associated with
exposure to air pollution of these emissions. However, we have not
quantified or monetized the benefits of reducing these emissions for
this rulemaking because information is not available to monetize
potential benefits and we are not aware of any new phosphate rock
calciners that will be constructed in the next three years.

F. What analysis of environmental justice did we conduct?

    Executive Order 12898 (59 FR 7629, February 16, 1994) establishes
federal executive policy on environmental justice. Its main provision
directs federal agencies, to the greatest extent practical and
permitted by law, to make environmental justice part of their mission
by identifying and addressing, as appropriate, disproportionately high
and adverse human health or environmental effects of their programs,
policies and activities on minority populations and low-income
populations in the U.S.
    The EPA has determined that this rule will not have
disproportionately high and adverse human health or environmental
effects on minority, low-

income, or indigenous populations because it increases the level of
environmental protection for all affected populations without having
any disproportionately high and adverse human health or environmental
effects on any population, including any minority or low-income
population. To gain a better understanding of the source category and
near source populations, the EPA conducted a proximity analysis on
phosphate facilities to identify any overrepresentation of minority,
low income, or indigenous populations. This analysis only gives some
indication of the prevalence of sub-populations that may be exposed to
air pollution from the sources; it does not identify the demographic
characteristics of the most highly affected individuals or communities,
nor does it quantify the level of risk faced by those individuals or
communities.
    The proximity analysis reveals that most demographic categories are
below or within 20 percent of their corresponding national averages.
The two exceptions are the minority and African American populations.
The ratio of African Americans living within 3 miles of any source
affected by this rule is 131 percent higher than the national average
(29 percent versus 13 percent). The percentage of minorities living
within 3 miles of any source affected by this rule is 37 percent above
the national average (35 percent versus 28 percent). The large minority
population is a direct result of the higher percentage of African
Americans living near these facilities (the other racial minorities are
below or equal to the national average). However, as noted previously,
we found the risks from these source categories to be acceptable for
all populations.
    The changes to the standard increase the level of environmental
protection for all affected populations by ensuring no future emission
increases from the source categories. The proximity analysis results
and the details concerning their development are presented in the
October 2012 memorandum, ``Environmental Justice Review: Phosphate
Fertilizer Production and Phosphoric Acid,'' a copy of which is
available in Docket ID No. EPA-HQ-OAR-2012-0522.

G. What analysis of children's environmental health did we conduct?

    While this action is not subject to Executive Order 13045 (62 FR
19885, April 23, 1997), we note that the current standards provide an
ample margin of safety to protect public health. Consideration of
children's health is accounted for in our risk analyses, which compare
projected exposures to various health benchmarks that are based on the
most sensitive populations.

VIII. Statutory and Executive Order Reviews

A. Executive Orders 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. The EPA analyzed the potential costs and benefits
associated with this action. The results are presented in sections
VII.C and E of this preamble.

B. Paperwork Reduction Act (PRA)

    The information collection activities in these rules have been
submitted for approval to OMB under the PRA. The Information Collection
Request (ICR) document that the EPA prepared has been assigned EPA ICR
number 1790.06. You can find a copy of the ICR in the docket for this
rule, and it is briefly summarized here. The information collection
requirements are not enforceable until OMB approves them.
    We are finalizing new paperwork requirements to the Phosphoric Acid
Manufacturing and Phosphate Fertilizer Production source categories in
the form of additional requirements for stack testing, performance
evaluations, and work practices for fugitive sources.
    We estimate 12 regulated entities are currently subject to 40 CFR
part 63, subpart AA and 11 regulated entities are currently subject to
40 CFR part 63, subpart BB and each will be subject to all applicable
standards. The annual monitoring, reporting, and recordkeeping burden
for these amendments to subpart AA and BB is estimated to be $224,000
per year (averaged over the first 3 years after the effective date of
the standards). This includes 670 labor hours per year at a total labor
cost of $55,000 per year, and total non-labor capital and operating and
maintenance costs of $169,000 per year. This estimate includes
performance tests, notifications, reporting and recordkeeping
associated with the new requirements for emission points and associated
control devices. The total burden to the federal government is
estimated to be 330 hours per year at a total labor cost of $17,000 per
year (averaged over the first 3 years after the effective date of the
standard). Burden is defined at 5 CFR 1320.3(b).
    An agency may not conduct or sponsor, and a person is not required
to respond to, a collection of information unless it displays a
currently valid OMB control number. The OMB control numbers for the
EPA's regulations in 40 CFR are listed in 40 CFR part 9. When OMB
approves this ICR, the Agency will announce that approval in the
Federal Register and publish a technical amendment to 40 CFR part 9 to
display the OMB control number for the approved information collection
activities contained in this final rule.

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. In
making this determination, the impact of concern is any significant
adverse economic impact on small entities. An agency may certify that a
rule will not have a significant economic impact on a substantial
number of small entities if the rule relieves regulatory burden, has no
net burden or otherwise has a positive economic effect on the small
entities subject to the rule. This rule will not impose any
requirements on small entities because we do not project that any small
entities will incur costs due to these rule amendments. We have
therefore concluded that this action will have no net regulatory burden
for all directly regulated small entities.

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. The 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 has tribal implications. However, it will neither
impose substantial direct compliance costs on federally recognized
tribal governments, nor preempt tribal law. The tribal implications are
primarily due to the close proximity of one facility to a tribe (the
Shoshone-Bannock).
    The EPA consulted with tribal officials under the EPA Policy on

Consultation and Coordination with Indian Tribes early in the process
of developing this regulation to permit them to have meaningful and
timely input into its development. The Agency provided an overview of
the source categories and rulemaking process during a monthly
teleconference with the National Tribal Air Association. Additionally,
we provided targeted outreach, including a visit to the Shoshone-
Bannock tribe and meeting with environmental leaders for the tribe.

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's health and risk assessments are contained in
sections V.A. and VI.A.

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) and 1 CFR
part 51

    This action involves technical standards. The EPA has decided to
use analytical methods of the Association of Official Analytical
Chemists (AOAC) and of the Association of Fertilizer and Phosphate
Chemists (AFPC). The AOAC methods include: AOAC Official Method 957.02
Phosphorus (Total) in Fertilizers, Preparation of Sample Solution, AOAC
Official Method 929.01 Sampling of Solid Fertilizers, AOAC Official
Method 929.02 Preparation of Fertilizer Sample, AOAC Official Method
978.01 Phosphorous (Total) in Fertilizers, Automated Method, AOAC
Official Method 969.02 Phosphorous (Total) in Fertilizers, Alkalimetric
Quinolinium Molybdophosphate Method, AOAC Official Method 962.02
Phosphorous (Total) in Fertilizers, Gravimetric Quinolinium
Molybdophosphate Method and Quinolinium Molybdophosphate Method 958.01
Phosphorous (Total) in Fertilizers, Spectrophotometric
Molybdovanadophosphate Method. The AFPC methods for analysis of
phosphate rock include: No. 1 Preparation of Sample, No. 3 Phosphorus-
P2O5 or
Ca3(PO4)2, Method A--Volumetric
Method, No. 3 Phosphorus-P2O5 or
Ca3(PO4)2, Method B--Gravimetric
Quimociac Method, No. 3 Phosphorus-P2O5 or
Ca3(PO4)2, Method C--
Spectrophotometric Method. The AFPC methods for analysis of phosphoric
acid, superphosphate, triple superphosphate and ammonium phosphates
include: No. 3 Total Phosphorus-P2O5, Method A-
Volumetric Method, No. 3 Total Phosphorus-P2O5,
Method B--Gravimetric Quimociac Method and No. 3 Total Phosphorus-
P2O5, Method C--Spectrophotometric Method.
    As discussed in the preamble of the proposal, under NESHAP subpart
AA and NESHAP subpart BB, we conducted searches for EPA Methods 5, 13A,
13B, and 30B. The EPA conducted searches through the Enhanced National
Standards Systems Network (NSSN) Database managed by the American
National Standards Institute (ANSI). We contacted voluntary consensus
standards (VCS) organizations, and accessed and searched their
databases. We did not identify any applicable VCS for EPA Methods 5,
13A, 13B, or 30B. Additional information for the VCS search and
determinations can be found in the memorandum, ``Voluntary Consensus
Standard Results for Phosphoric Acid Manufacturing and Phosphate
Fertilizer Production RTR and Standards of Performance for Phosphate
Processing,'' which is available in the docket for this action. The EPA
solicited comments on VCS and invited the public to identify
potentially applicable VCS; however, we did not receive comments
regarding this aspect of NESHAP subpart AA and NESHAP subpart BB.
    The EPA is incorporating, into NESHAP subpart AA and NESHAP subpart
BB, the following guidance document: EPA-454/R-98-015, Office Of Air
Quality Planning And Standards (OAQPS), Fabric Filter Bag Leak
Detection Guidance, September 1997. This guidance document provides
procedures for selecting, installing, setting up, adjusting, and
operating a bag leak detection system; and also includes quality
assurance procedures. This guidance document is readily accessible at
http://www.epa.gov/ttn/emc/cem.html.

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

    The EPA believes the human health or environmental risk addressed
by this action will not have potential disproportionately high and
adverse human health or environmental effects on minority, low-income,
or indigenous populations because it increases the level of protection
provided to human health or the environment. The results of this
evaluation are contained in the memorandum titled ``Environmental
Justice Review: Phosphate Fertilizer Production and Phosphoric Acid,''
which is available in Docket ID No. EPA-HQ-OAR-2012-0522, and are
discussed in section VII.F of this preamble.

K. Congressional Review Act

    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 U.S. This action is not a ``major rule'' as defined by 5 U.S.C.
804(2).

List of Subjects

40 CFR Part 60

    Environmental protection, Air pollution control, Fertilizers,
Fluoride, Particulate matter, Phosphate, Reporting and recordkeeping
requirements.

40 CFR Part 63

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

    Dated: July 21, 2015.
Gina McCarthy,
Administrator.

    For the reasons stated in the preamble, parts 60 and 63 of title
40, chapter I, of the Code of Federal Regulations are amended as
follows:

PART 60--STANDARDS OF PERFORMANCE FOR NEW STATIONARY SOURCES

0
1. The authority citation for part 60 continues to read as follows:

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

Subpart T--Standards of Performance for the Phosphate Fertilizer
Industry: Wet-Process Phosphoric Acid Plants

0
2. Section 60.200 is amended by revising paragraph (a) to read as
follows:

Sec.  60.200  Applicability and designation of affected facility.

    (a) The affected facility to which the provisions of this subpart
apply is each wet-process phosphoric acid plant having a design
capacity of more than 15 tons of equivalent P2O5
feed per calendar day.
* * * * *

0
3. Section 60.201 is amended by revising paragraph (a) to read as
follows:

Sec.  60.201  Definitions.

* * * * *
    (a) Wet-process phosphoric acid plant means any facility
manufacturing phosphoric acid by reacting phosphate rock and acid. A
wet-process phosphoric acid plant includes: Reactors, filters,
evaporators, and hot wells.
* * * * *

0
4. Section 60.203 is amended by revising paragraph (c) and adding
paragraph (d) to read as follows:

Sec.  60.203  Monitoring of operations.

* * * * *
    (c) The owner or operator of any wet-process phosphoric acid plant
subject to the provisions of this part shall install, calibrate,
maintain, and operate a monitoring device which continuously measures
and permanently records the total pressure drop across the absorber.
The monitoring device shall have an accuracy of 5 percent
over its operating range.
    (d) Any facility under Sec.  60.200(a) that commences construction,
modification or reconstruction after November 7, 2014 is subject to the
requirements of this paragraph instead of the requirements in paragraph
(c) of this section. If an absorber is used to comply with Sec.
60.202, then the owner or operator shall continuously monitor pressure
drop through the absorber and meet the requirements specified in
paragraphs (d)(1) through (4) of this section.
    (1) The owner or operator shall install, calibrate, maintain, and
operate a continuous monitoring system (CMS) that continuously measures
and permanently records the pressure at the gas stream inlet and outlet
of the absorber. The pressure at the gas stream inlet of the absorber
may be measured using amperage on the blower if a correlation between
pressure and amperage is established.
    (2) The CMS must have an accuracy of 5 percent over the
normal range measured or 0.12 kilopascals (0.5 inches of water column),
whichever is greater.
    (3) The owner or operator shall establish an allowable range for
the pressure drop through the absorber. The allowable range is 20 percent of the arithmetic average of the three test runs
conducted during the performance test required in Sec.  60.8. 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.
    (4) The owner or operator shall demonstrate continuous compliance
by maintaining the daily average pressure drop through the absorber to
within the allowable range established in paragraph (d)(3) of this
section. The daily average pressure drop through the absorber for each
operating day shall be calculated using the data recorded by the
monitoring system. If the emissions unit operation is continuous, the
operating day is a 24-hour period. If the emissions unit operation is
not continuous, the operating day is the total number of hours of
control device operation per 24-hour period. Valid data points must be
available for 75 percent of the operating hours in an operating day to
compute the daily average.

0
5. Subpart T is amended by adding Sec.  60.205 to read as follows:

Sec.  60.205  Recordkeeping.

    Any facility under Sec.  60.200(a) that commences construction,
modification or reconstruction after November 7, 2014 is subject to the
requirements of this section. You must maintain the records identified
as specified in Sec.  60.7(f) and in paragraphs (a) and (b) of this
section. All records required by this subpart must be maintained on
site for at least 5 years.
    (a) Records of the daily average pressure. Records of the daily
average pressure drop through the absorber.
    (b) Records of deviations. A deviation is determined to have
occurred when the monitoring data or lack of monitoring data result in
any one of the criteria specified in paragraphs (b)(1) and (2) of this
section being met.
    (1) A deviation occurs when the daily average value of a monitored
operating parameter is less than the minimum pressure drop, or greater
than the maximum pressure drop established in Sec.  60.203(d)(3).
    (2) A deviation occurs when the monitoring data are not available
for at least 75 percent of the operating hours in a day.

Subpart U--Standards of Performance for the Phosphate Fertilizer
Industry: Superphosphoric Acid Plants

0
6. Section 60.210 is amended by revising paragraph (a) to read as
follows:

Sec.  60.210  Applicability and designation of affected facility.

    (a) The affected facility to which the provisions of this subpart
apply is each superphosphoric acid plant having a design capacity of
more than 15 tons of equivalent P2O5 feed per
calendar day.
* * * * *

0
7. Section 60.211 is amended by revising paragraph (a) to read as
follows:

Sec.  60.211  Definitions.

* * * * *
    (a) Superphosphoric acid plant means any facility that concentrates
wet-process phosphoric acid to 66 percent or greater
P2O5 content by weight for eventual consumption
as a fertilizer. A superphosphoric acid plant includes: evaporators,
hot wells, acid sumps, oxidation reactors, and cooling tanks. An
oxidation reactor includes any equipment or step that uses an oxidizing
agent (e.g., nitric acid, ammonium nitrate, or potassium permanganate)
to treat superphosphoric acid.
* * * * *

0
8. Section 60.213 is amended by revising paragraph (c) and adding
paragraph (d) to read as follows:

Sec.  60.213  Monitoring of operations.

* * * * *
    (c) Except as specified in paragraph (d) of this section, the owner
or operator of any superphosphoric acid plant subject to the provisions
of this part shall install, calibrate, maintain, and operate a
monitoring device which continuously measures and permanently records
the total pressure drop across the absorber. The monitoring device
shall have an accuracy of 5 percent over its operating
range.
    (d) Any affected facility as defined in Sec.  60.210(a) that
commences construction, modification or reconstruction after November
7, 2014 is subject to the requirements of this paragraph instead of the
requirements in paragraph (c) of this section. If an absorber is used
to comply with Sec.  60.212, then the owner or operator shall
continuously monitor pressure drop through the absorber and meet the
requirements specified in paragraphs (d)(1) through (4) of this
section.
    (1) The owner or operator shall install, calibrate, maintain, and
operate a continuous monitoring system (CMS) that continuously measures
and permanently records the pressure at the gas stream inlet and outlet
of the absorber. The pressure at the gas stream inlet of the absorber
may be measured using amperage on the blower if a correlation between
pressure and amperage is established.
    (2) The CMS must have an accuracy of 5 percent over the
normal range measured or 0.12 kilopascals (0.5 inches of water column),
whichever is greater.

    (3) The owner or operator shall establish an allowable range for
the pressure drop through the absorber. The allowable range is 20 percent of the arithmetic average of the three test runs
conducted during the performance test required in Sec.  60.8. 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.
    (4) The owner or operator shall demonstrate continuous compliance
by maintaining the daily average pressure drop through the absorber to
within the allowable range established in paragraph (d)(3) of this
section. The daily average pressure drop through the absorber for each
operating day shall be calculated using the data recorded by the
monitoring system. If the emissions unit operation is continuous, the
operating day is a 24-hour period. If the emissions unit operation is
not continuous, the operating day is the total number of hours of
control device operation per 24-hour period. Valid data points must be
available for 75 percent of the operating hours in an operating day to
compute the daily average.

0
9. Subpart U is amended by adding Sec.  60.215 to read as follows:

Sec.  60.215  Recordkeeping.

    An affected facility as defined in Sec.  60.210(a) that commences
construction, modification, or reconstruction after November 7, 2014 is
subject to the requirements of this section. You must maintain the
records identified as specified in Sec.  60.7(f) and in paragraphs (a)
and (b) of this section. All records required by this subpart must be
maintained on site for at least 5 years.
    (a) Records of the daily average pressure. Records of the daily
average pressure drop through the absorber.
    (b) Records of deviations. A deviation is determined to have
occurred when the monitoring data or lack of monitoring data result in
any one of the criteria specified in paragraphs (b)(1) and (2) of this
section being met.
    (1) A deviation occurs when the daily average value of a monitored
operating parameter is less than the minimum pressure drop, or greater
than the maximum pressure drop established in Sec.  60.213(d)(3).
    (2) A deviation occurs when the monitoring data are not available
for at least 75 percent of the operating hours in a day.

Subpart V--Standards of Performance for the Phosphate Fertilizer
Industry: Diammonium Phosphate Plants

0
10. Section 60.223 is amended by revising paragraph (c) and adding
paragraph (d) to read as follows:

Sec.  60.223  Monitoring of operations.

* * * * *
    (c) Except as specified in paragraph (d) of this section, the owner
or operator of any granular diammonium phosphate plant subject to the
provisions of this subpart shall install, calibrate, maintain, and
operate a monitoring device which continuously measures and permanently
records the total pressure drop across the scrubbing system. The
monitoring device shall have an accuracy of 5 percent over
its operating range.
    (d) Any affected facility as defined in Sec.  60.220(a) that
commences construction, modification, or reconstruction after November
7, 2014 is subject to the requirements of this paragraph instead of the
requirements in paragraph (c) of this section. If an absorber is used
to comply with Sec.  60.222, then the owner or operator shall
continuously monitor pressure drop through the absorber and meet the
requirements specified in paragraphs (d)(1) through (4) of this
section.
    (1) The owner or operator shall install, calibrate, maintain, and
operate a continuous monitoring system (CMS) that continuously measures
and permanently records the pressure at the gas stream inlet and outlet
of the absorber. The pressure at the gas stream inlet of the absorber
may be measured using amperage on the blower if a correlation between
pressure and amperage is established.
    (2) The CMS must have an accuracy of 5 percent over the
normal range measured or 0.12 kilopascals (0.5 inches of water column),
whichever is greater.
    (3) The owner or operator shall establish an allowable range for
the pressure drop through the absorber. The allowable range is 20 percent of the arithmetic average of the three test runs
conducted during the performance test required in Sec.  60.8. 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.
    (4) The owner or operator shall demonstrate continuous compliance
by maintaining the daily average pressure drop through the absorber to
within the allowable range established in paragraph (d)(3) of this
section. The daily average pressure drop through the absorber for each
operating day shall be calculated using the data recorded by the
monitoring system. If the emissions unit operation is continuous, the
operating day is a 24-hour period. If the emissions unit operation is
not continuous, the operating day is the total number of hours of
control device operation per 24-hour period. Valid data points must be
available for 75 percent of the operating hours in an operating day to
compute the daily average.

0
11. Section 60.224 is amended by revising paragraph (b)(3)(ii) to read
as follows:

Sec.  60.224  Test methods and procedures.

* * * * *
    (b) * * *
    (3) * * *
    (ii) The Association of Official Analytical Chemists (AOAC) Method
9 (incorporated by reference--see Sec.  60.17) shall be used to
determine the P2O5 content (Rp) of the
feed.

0
12. Subpart V is amended by adding Sec.  60.225 to read as follows:

Sec.  60.225  Recordkeeping.

    An affected facility as defined in Sec.  60.220(a) that commences
construction, modification, or reconstruction after November 7, 2014 is
subject to the requirements of this section. You must maintain the
records identified as specified in Sec.  60.7(f) and in paragraphs (a)
and (b) of this section. All records required by this subpart must be
maintained on site for at least 5 years.
    (a) Records of the daily average pressure drop through the
absorber.
    (b) Records of deviations. A deviation is determined to have
occurred when the monitoring data or lack of monitoring data result in
any one of the criteria specified in paragraphs (b)(1) and (2) of this
section being met.
    (1) A deviation occurs when the daily average value of a monitored
operating parameter is less than the minimum pressure drop, or greater
than the maximum pressure drop established in Sec.  60.223(d)(3).
    (2) A deviation occurs when the monitoring data are not available
for at least 75 percent of the operating hours in a day.

Subpart W--Standards of Performance for the Phosphate Fertilizer
Industry: Triple Superphosphate Plants

0
13. Section 60.230 is amended by revising paragraph (a) to read as
follows:

Sec.  60.230  Applicability and designation of affected facility.

    (a) The affected facility to which the provisions of this subpart
apply is each triple superphosphate plant having a design capacity of
more than 15 tons of equivalent P2O5 feed per
calendar day. For the purpose of this subpart, the affected facility
includes any combination of: mixers, curing belts (dens), reactors,
granulators, dryers, coolers, screens, mills, and facilities that store
run-of-pile triple superphosphate.
* * * * *

0
14. Section 60.233 is revised to read as follows:

Sec.  60.233  Monitoring of operations.

    (a) The owner or operator of any triple superphosphate plant
subject to the provisions of this subpart shall install, calibrate,
maintain, and operate a flow monitoring device that can be used to
determine the mass flow of phosphorus-bearing feed material to the
process. The flow monitoring device shall have an accuracy of 5 percent over its operating range.
    (b) The owner or operator of any triple superphosphate plant shall
maintain a daily record of equivalent P2O5 feed
by first determining the total mass rate in Mg/hr of phosphorus-bearing
feed using a flow monitoring device meeting the requirements of
paragraph (a) of this section and then by proceeding according to Sec.
60.234(b)(3).
    (c) Except as specified in paragraph (d) of this section, the owner
or operator of any triple superphosphate plant subject to the
provisions of this part shall install, calibrate, maintain, and operate
a monitoring device that continuously measures and permanently records
the total pressure drop across the absorber. The monitoring device
shall have an accuracy of 5 percent over its operating
range.
    (d) Any facility under Sec.  60.230(a) that commences construction,
modification, or reconstruction after November 7, 2014 is subject to
the requirements of this paragraph instead of the requirements in
paragraph (c) of this section. If an absorber is used to comply with
Sec.  60.232, then the owner or operator shall continuously monitor
pressure drop through the absorber and meet the requirements specified
in paragraphs (d)(1) through (4) of this section.
    (1) The owner or operator shall install, calibrate, maintain, and
operate a continuous monitoring system (CMS) that continuously measures
and permanently records the pressure at the gas stream inlet and outlet
of the absorber. The pressure at the gas stream inlet of the absorber
may be measured using amperage on the blower if a correlation between
pressure and amperage is established.
    (2) The CMS must have an accuracy of 5 percent over the
normal range measured or 0.12 kilopascals (0.5 inches of water column),
whichever is greater.
    (3) The owner or operator shall establish an allowable range for
the pressure drop through the absorber. The allowable range is 20 percent of the arithmetic average of the three test runs
conducted during the performance test required in Sec.  60.8. 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.
    (4) The owner or operator shall demonstrate continuous compliance
by maintaining the daily average pressure drop through the absorber to
within the allowable range established in paragraph (d)(3) of this
section. The daily average pressure drop through the absorber for each
operating day shall be calculated using the data recorded by the
monitoring system. If the emissions unit operation is continuous, the
operating day is a 24-hour period. If the emissions unit operation is
not continuous, the operating day is the total number of hours of
control device operation per 24-hour period. Valid data points must be
available for 75 percent of the operating hours in an operating day to
compute the daily average.

0
15. Subpart W is amended by adding Sec.  60.235 to read as follows:

Sec.  60.235  Recordkeeping.

    Any facility under Sec.  60.230(a) that commences construction,
modification, or reconstruction after November 7, 2014 is subject to
the requirements of this section. You must maintain the records
identified as specified in Sec.  60.7(f) and in paragraphs (a) and (b)
of this section. All records required by this subpart must be
maintained onsite for at least 5 years.
    (a) Records of the daily average pressure drop through the
absorber.
    (b) Records of deviations. A deviation is determined to have
occurred when the monitoring data or lack of monitoring data result in
any one of the criteria specified in paragraphs (b)(1) and (2) of this
section being met.
    (1) A deviation occurs when the daily average value of a monitored
operating parameter is less than the minimum pressure drop, or greater
than the maximum pressure drop established in Sec.  60.233(d)(3).
    (2) A deviation occurs when the monitoring data are not available
for at least 75 percent of the operating hours in a day.

Subpart X--Standards of Performance for the Phosphate Fertilizer
Industry: Granular Triple Superphosphate Storage Facilities

0
16. Section 60.243 is amended by revising paragraph (c) and adding (e)
to read as follows:

Sec.  60.243  Monitoring of operations.

* * * * *
    (c) Except as specified in paragraph (e) of this section, the owner
or operator of any granular triple superphosphate storage facility
subject to the provisions of this subpart shall install, calibrate,
maintain, and operate a monitoring device that continuously measures
and permanently records the total pressure drop across any absorber.
The monitoring device shall have an accuracy of 5 percent
over its operating range.
* * * * *
    (e) Any facility under Sec.  60.240(a) that commences construction,
modification, or reconstruction after November 7, 2014 is subject to
the requirements of this paragraph instead of the requirements in
paragraph (c) of this section. If an absorber is used to comply with
Sec.  60.232, then the owner or operator shall continuously monitor
pressure drop through the absorber and meet the requirements specified
in paragraphs (e)(1) through (4) of this section.
    (1) The owner or operator shall install, calibrate, maintain, and
operate a continuous monitoring system (CMS) that continuously measures
and permanently records the pressure at the gas stream inlet and outlet
of the absorber. The pressure at the gas stream inlet of the absorber
may be measured using amperage on the blower if a correlation between
pressure and amperage is established.
    (2) The CMS must have an accuracy of 5 percent over the
normal range measured or 0.12 kilopascals (0.5 inches of water column),
whichever is greater.
    (3) The owner or operator shall establish an allowable range for
the

pressure drop through the absorber. The allowable range is 20 percent of the arithmetic average of the three test runs
conducted during the performance test required in Sec.  60.8. 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.
    (4) The owner or operator shall demonstrate continuous compliance
by maintaining the daily average pressure drop through the absorber to
within the allowable range established in paragraph (e)(3) of this
section. The daily average pressure drop through the absorber for each
operating day shall be calculated using the data recorded by the
monitoring system. If the emissions unit operation is continuous, the
operating day is a 24-hour period. If the emissions unit operation is
not continuous, the operating day is the total number of hours of
control device operation per 24-hour period. Valid data points must be
available for 75 percent of the operating hours in an operating day to
compute the daily average.

0
17. Subpart X is amended by adding Sec.  60.245 to read as follows:

Sec.  60.245  Recordkeeping.

    Any facility under Sec.  60.240(a) that commences construction,
modification, or reconstruction after November 7, 2014 is subject to
the requirements of this section. You must maintain the records
identified as specified in Sec.  60.7(f) and in paragraphs (a) and (b)
of this section. All records required by this subpart must be
maintained onsite for at least 5 years.
    (a) Records of the daily average pressure drop through the
absorber.
    (b) Records of deviations. A deviation is determined to have
occurred when the monitoring data or lack of monitoring data result in
any one of the criteria specified in paragraphs (b)(1) and (2) of this
section being met.
    (1) A deviation occurs when the daily average value of a monitored
operating parameter is less than the minimum pressure drop, or greater
than the maximum pressure drop established in Sec.  60.243(e)(3).
    (2) A deviation occurs when the monitoring data are not available
for at least 75 percent of the operating hours in a day.

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

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

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

Subpart A--General Provisions

0
19. Section 63.14 is amended by revising paragraphs (b), (c)(1) through
(7), and (l)(2) to read as follows:

Sec.  63.14  Incorporations by reference.

* * * * *
    (b) The Association of Florida Phosphate Chemists, P.O. Box 1645,
Bartow, Florida 33830.
    (1) Book of Methods Used and Adopted By The Association of Florida
Phosphate Chemists, Seventh Edition 1991:
    (i) Section IX, Methods of Analysis for Phosphate Rock, No. 1
Preparation of Sample, IBR approved for Sec.  63.606(f), Sec.
63.626(f).
    (ii) Section IX, Methods of Analysis for Phosphate Rock, No. 3
Phosphorus-P2O5 or Ca3(PO4)2, Method A--Volumetric Method, IBR approved
for Sec.  63.606(f), Sec.  63.626(f).
    (iii) Section IX, Methods of Analysis for Phosphate Rock, No. 3
Phosphorus-P2O5 or Ca3(PO4)2, Method B--Gravimetric Quimociac Method,
IBR approved for Sec.  63.606(f), Sec.  63.626(f).
    (iv) Section IX, Methods of Analysis For Phosphate Rock, No. 3
Phosphorus-P2O5 or Ca3(PO4)2, Method C--Spectrophotometric Method, IBR
approved for Sec.  63.606(f), Sec.  63.626(f).
    (v) Section XI, Methods of Analysis for Phosphoric Acid,
Superphosphate, Triple Superphosphate, and Ammonium Phosphates, No. 3
Total Phosphorus-P2O5, Method A--Volumetric Method, IBR approved for
Sec.  63.606(f), Sec.  63.626(f), and (g).
    (vi) Section XI, Methods of Analysis for Phosphoric Acid,
Superphosphate, Triple Superphosphate, and Ammonium Phosphates, No. 3
Total Phosphorus-P2O5, Method B--Gravimetric Quimociac Method, IBR
approved for Sec.  63.606(f), Sec.  63.626(f), and (g).
    (vii) Section XI, Methods of Analysis for Phosphoric Acid,
Superphosphate, Triple Superphosphate, and Ammonium Phosphates, No. 3
Total Phosphorus-P2O5, Method C--Spectrophotometric Method, IBR
approved for Sec.  63.606(f), Sec.  63.626(f), and (g).
    (2) [Reserved]
    (c) * * *
    (1) AOAC Official Method 929.01 Sampling of Solid Fertilizers,
Sixteenth edition, 1995, IBR approved for Sec.  63.626(g).
    (2) AOAC Official Method 929.02 Preparation of Fertilizer Sample,
Sixteenth edition, 1995, IBR approved for Sec.  63.626(g).
    (3) AOAC Official Method 957.02 Phosphorus (Total) in Fertilizers,
Preparation of Sample Solution, Sixteenth edition, 1995, IBR approved
for Sec.  63.626(g).
    (4) AOAC Official Method 958.01 Phosphorus (Total) in Fertilizers,
Spectrophotometric Molybdovanadophosphate Method, Sixteenth edition,
1995, IBR approved for Sec.  63.626(g).
    (5) AOAC Official Method 962.02 Phosphorus (Total) in Fertilizers,
Gravimetric Quinolinium Molybdophosphate Method, Sixteenth edition,
1995, IBR approved for Sec.  63.626(g).
    (6) AOAC Official Method 969.02 Phosphorus (Total) in Fertilizers,
Alkalimetric Quinolinium Molybdophosphate Method, Sixteenth edition,
1995, IBR approved for Sec.  63.626(g).
    (7) AOAC Official Method 978.01 Phosphorus (Total) in Fertilizers,
Automated Method, Sixteenth edition, 1995, IBR approved for Sec.
63.626(g).
* * * * *
    (l) * * *
    (2) EPA-454/R-98-015, Office Of Air Quality Planning And Standards
(OAQPS), Fabric Filter Bag Leak Detection Guidance, September 1997, IBR
approved for Sec. Sec.  63.548(e), 63.606(m), 63.607(b), 63.626(h),
63.627(b), 63.7525(j), and 63.11224(f).
* * * * *

0
20. Part 63 is amended by revising subpart AA to read as follows:

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

Sec.
63.600 Applicability.
63.601 Definitions.
63.602 Standards and compliance dates.
63.603 [Reserved]
63.604 [Reserved]
63.605 Operating and monitoring requirements.
63.606 Performance tests and compliance provisions.
63.607 Notification, recordkeeping, and reporting requirements.
63.608 General requirements and applicability of general provisions
of this part.
63.609 [Reserved]
63.610 Exemption from new source performance standards.
63.611 Implementation and enforcement.

Table 1 to Subpart AA of Part 63--Existing Source Emission Limits
Table 2 to Subpart AA of Part 63--New Source Emission Limits
Table 3 to Subpart AA of Part 63--Monitoring Equipment Operating
Parameters
Table 4 to Subpart AA of Part 63--Operating Parameters, Operating
Limits and Data Monitoring, Recordkeeping and Compliance Frequencies
Table 5 to Subpart AA of Part 63--Calibration and Quality Control
Requirements for Continuous Parameter Monitoring System (CPMS)
Appendix A to Subpart AA of Part 63--Applicability of General
Provisions (40 CFR part 63, subpart A) to Subpart AA

Sec.  63.600  Applicability.

    (a) Except as provided in paragraphs (c) and (d) of this section,
you are subject to the requirements of this subpart if you own or
operate a phosphoric acid manufacturing plant that is a major source as
defined in Sec.  63.2. You must comply with the emission limitations,
work practice standards, and operating parameter requirements specified
in this subpart at all times.
    (b) The requirements of this subpart apply to emissions of
hazardous air pollutants (HAP) emitted from the following affected
sources at a phosphoric acid manufacturing plant:
    (1) Each wet-process phosphoric acid process line.
    (2) Each evaporative cooling tower.
    (3) Each phosphate rock dryer.
    (4) Each phosphate rock calciner.
    (5) Each superphosphoric acid process line.