are widely used to control SO2 emissions from other coal combustion
sources.  A dry scrubber includes a downstream fabric filter and would
obviate the need for a separate PM control device.  Further, a dry
scrubber could be used downstream of an existing wet scrubber designed
for PM control.

Response:  EPA considered, and discussed in the supporting documentation
(see EPA-HQ-OAR-2008-0260-0080, p. 7), the use of a dry scrubber as
suggested by the commenter.  An affected facility would be free to
utilize any technology desired as long as the emission limits were
achieved.

Comment:  One commenter (093) stated that one of the two technologies
EPA has identified to meet the SO2 limit for modified, reconstructed,
and new thermal dryers, sorbent injection, requires a design that
includes injection locations and sufficient residence time, which can be
incorporated into “a new thermal dryer.”  Under 40 CFR 60.15, a
thermal dryer may be considered “modified” when there is only a
relatively small capital investment that causes a statistically
significant increase in SO2 emissions.  “Modification,” therefore,
does not create an opportunity to incorporate absorbent injection sites
and residence time into an existing thermal dryer, and
“reconstruction” may not either.  For anything other than a new
unit, then, the only technology EPA has identified as meeting the
proposed SO2 limits is “spraying caustic on the coal prior to the
drying chamber.”  Yet EPA acknowledges that it does not have data
demonstrating this control technology:  “The caustic approach is
presently used at one facility, and the salt produced is removed by the
PM control device.  We do not have detailed information on the
contribution of each mechanism on overall control.  However, if we
assume…” (74 FR 25,310).  This is an insufficient basis for EPA to
impose emission limits on thermal dryers at all, and certainly not to
impose emission limits on a range of designs that may be incorporated
into cement plants.

Response:  EPA also identified caustic injection into a wet scrubber as
a technology for reducing SO2 emissions (see EPA-HQ-OAR-2008-0260-0080,
p. 7).   EPA believes that this technology is applicable to new,
reconstructed, and modified facilities.  See the response to comment
3.3.8 for a discussion of the applicability of Subpart Y to Portland
cement plants.

<IP_ADDRESS>	SO2 Emission Limit Levels

Comment:  One commenter (096) stated that information in the proposal
preamble and support documentation show that the SO2 emissions limits
for new and reconstructed coal dryers should be set lower than the
proposed level.  The selection of the SO2 emission limits for coal
dryers must be reconsidered specifically to analyze separate standards
for new, reconstructed, and modified affected sources.  Reasons
presented by the commenter for setting lower SO2 emissions limits are:

Proposal preamble states that “[w]et scrubbers designed specifically
for SO2 control are able to achieve greater than 95 percent
reduction.”  This is confirmed in the Thermal Dryer Memorandum, page
7, but EPA dismisses wet scrubbers from further consideration, as the
wet scrubbers currently used on existing thermal dryers are designed for
PM control and not specifically for SO2 controls and high levels of SO2
control may be difficult to achieve without redesign of the wet scrubber
(74 FR 25310).  This is not a valid reason for eliminating a viable
technology from consideration, especially for a new or a reconstructed
coal dryer.  Wet scrubbers are widely used on similar sources and, as
EPA recognizes, routinely achieve greater than 95 percent reduction.
Therefore, EPA may not ignore the possibility of installing wet
scrubbers for SO2 control, particularly for new or reconstructed coal
dryers.  It would be arbitrary and capricious for EPA to adopt a 50
percent control option in the face of a clearly superior technology that
is rejected without analysis.

Even if EPA ultimately determines that wet scrubbers are not BDT for SO2
control for at least some coal dyers, the Subpart Y SO2 emission limit
must be more stringent for those dryers.  EPA projects that using a
caustic spray for SO2 control will achieve approximately a 50 percent
reduction in SO2 emissions (74 FR 25310).  In contrast, EPA notes that
sorbent injection controls that use sodium-based agents can meet removal
efficiencies of 90 percent (74 FR 25310).  Given that sorbent injection
is capable of significantly higher removal efficiencies, it is arbitrary
and capricious for EPA to assert that dry sorbent injection and spraying
caustic on the coal prior to drying are both BDT for SO2 reduction from
new, modified, and reconstructed thermal dryers.  The results obtained
are not equivalent, and “dumbing-down” the removal efficiency of the
superior technology to preserve multiple compliance pathways for
industry violates the plain language of the CAA, which requires
standards of performance reflecting application of the “best system of
emission reduction” (42 U.S.C. § 7411(a)(1)).

Response:  EPA indicated in the May 27, 2009, supplemental proposal that
it was considering an SO2 percent reduction requirement of between 50
and 90 percent for the final rule (74 FR 25311).  EPA has reviewed the
available data and believes that a 90 percent removal value is
appropriate for new, reconstructed, and modified thermal dryers.

3.3.6	Coal Dryer Combined NOx/CO Emission Limit

Comment:  Many commenters (093, 096, 085, 095, 115, and 117) stated that
EPA proposal to set a combined NOX and CO emissions limit for coal
dryers is inappropriate.  Commenters presented different reasons
summarized below to support this conclusion.  One commenter (096) stated
explicitly that separate NOX and CO emissions limits must be set for
coal dryers. Reasons cited by individual commenters are:

A combined NOX/CO limit enables permitting authorities to trade off
higher NOX emissions for lower CO emissions, and vice versa.  EPA
asserts that this approach is a way to “provide additional compliance
strategy options for the regulated community, while still providing an
equivalent level of environmental protection” (74 FR 25311).  However,
this statement, and EPA’s proposed approach of allowing states to
trade NOX and CO emissions at essentially a 1:1 ratio, ignores that CO
and NOX are different pollutants that do not have equivalent
environmental impacts.  For example, through their larger role in the
formation of ozone, NOX emissions may have a significantly broader
impact than CO emissions, the harmful impacts of which may be much more
localized. NOx emissions also contribute to acid rain that may occur
long distances from the permitted source.  For example, without such a
backstop requirement, states may elect to implement more aggressive
limits for CO than for NOx.  Because NOX emissions may cause significant
harm farther from the source, there could be a perverse incentive for
states to ask sources to ratchet down CO emissions at the expense of
higher NOX emissions, which would inhibit downwind efforts to reduce
ozone pollution and acid rain.

A combined NOX/CO limit violates CAA for the reason that the proposed
combined limit is based on an assumed CO emissions rate that does not
“reflect the degree of emission limitation achievable through the
application of the best system of emission reduction” (42 U.S.C.
§7411(a)(1).  EPA admits that the presumed levels of CO emissions
(0.45 lb/MMBtu for modified and reconstructed dryers and 0.25 lb/MMBtu
for new dryers) are levels that are already surpassed by nearly all
existing industrial boilers.  EPA’s data on these sources “indicate
that 92 percent of existing small coal-fired boilers are achieving a
rate of . . . 0.25 lb/MMBtu . . . and 98 percent are achieving a rate
of . . . 0.45 lb/MMBtu” (74 FR 25312).  EPA has not explained why
industrial boilers would be capable of meeting more stringent CO limits
than thermal dryers.

Test data provided in the docket indicates a wide variation in test
results, especially for CO. Test data is almost exclusively based on
bituminous coal drying operations.  These data do not support the
conclusion that the proposed combined NOX/CO limit is applicable across
all grades of coal.  One commenter (085) provided a review of the data
cited by EPA.

Combustion controls currently represent BDT in use by the source
category.  Going beyond the demonstrated technologies for the source
category (e.g., incorporating post combustion control technologies,
specifically selective non-catalytic reduction (SNCR) on new thermal
dyers) is not required in developing NSPS.  Other regulatory programs
exist for advancing control technologies.

Commenter 093 does not believe that EPA has sufficient data to support
the proposed NOX standards, especially for existing, modified or
reconstructed, thermal dryers, and EPA has not demonstrated that thermal
dryers, with different design and function, can meet the same
limitations as coal-fired boilers.  EPA has identified combustion
controls that may not be available as the basis for the proposed NOX
standards, especially for existing thermal dryers.

Response:  EPA has concluded that the use of a combined NOX/CO limit is
appropriate because it acknowledges the inherent trade-off between the
two pollutants (i.e., a decrease in emissions of one often leads to an
increase in emissions of the other).  This approach provides flexibility
to State environmental agencies to minimize the particular pollutant of
concern to lessen the overall environmental and health impacts of the
two pollutants.  Individual separate limits could reduce the flexibility
required to minimize overall health and environmental impacts.  EPA has
based the combined NOX/CO limit on what it believes to be adequate data
from thermal dryers at subpart Y facilities; thus, the comparison to
industrial boilers is misplaced.  In addition, as the Court has noted,
“[t]he ‘adequately demonstrated’ requirement does not imply that
any [covered facility] now in existence be able to meet the proposed
standards.  CAA section 111 looks toward what may be fairly be projected
for the regulated future, rather than the state of the art at
present.” Portland Cement  Ass’n v. Ruckenshaus, 486 F.2d 375, 391
(D.C. Cir. 1973).

3.3.7	Coal Dryer VOC Emissions Limit

Comment:  One commenter (096) disagrees with EPA’s rationale for not
setting coal dryer VOC standards for the reasons summarized below.

EPA asserts that “VOC and CO emissions would be minimized” because
new thermal dryers would “likely use a gas recirculation design” (74
FR 25312); but, this language only demonstrates that EPA has not
fulfilled its statutory obligation.  If gas recirculation thermal dryers
are effective at reducing VOC and CO, then EPA must set standards of
performance for VOC and CO, which, at minimum, reflect the use of a gas
recirculation thermal dryer.

EPA asserts that not setting a standard for VOC is reasonable because
“by setting an emissions limit that contains a CO emissions rate, we
are minimizing the VOC emissions that result from incomplete
combustion” (74 FR 25312).  However, the proposed combined NOx and CO
standard provides no assurance that VOC emissions will be minimized
because CO emissions are just one component of the combined NOx and CO
standard.  Dryers could meet the combined standard by tailoring
combustion controls to minimize NOx emissions, which would result in
high levels of both CO and VOC emissions.  Further, there is no
demonstration on the record that there is any relationship between CO
and VOC emissions.

EPA asserts that omitting standards for VOC is acceptable because EPA
“ha[s] not identified a method for control of VOC emissions beyond
combustion controls” (74 FR 25312).  VOC can be controlled by a number
of methods, including activated carbon absorption and a regenerative
thermal oxidizer.

EPA explained that it could not set a standard for VOC emissions that
“would be achievable for variable coal types across the country”
because the VOC emissions from the coal bed itself are variable (74 FR
25312).  However, even if the extent of coal bed VOC emissions vary
across the country that does not excuse EPA from adopting a standard of
performance to limit VOC emissions.  For example, EPA could adopt a
standard for VOC removal efficiency that is based on oxidation of VOC in
a recirculation thermal dryer.  In this rulemaking, EPA has proposed SO2
standards for dryers that are based in part on removal efficiency, but
EPA has not explained why it has not proposed a similar approach for VOC
emissions.  The sulfur content of coals also vary widely across the
country, from less than 1 lb/MMBtu for some western coals to over 8
lb/MMBtu for some eastern coals.  This did not impede EPA from setting
an SO2 standard.

Response:   EPA has discretion to determine which pollutants are
appropriate for regulation in a particular NSPS.  In this case, for the
reasons noted, EPA concluded that it was not appropriate or feasible to
establish a standard of performance for VOC emissions from coal
preparation and processing plants at this time.  This conclusion does
not prohibit EPA from establishing such a standard in a future
rulemaking.  EPA disagrees with the commenter’s suggestion that a
standard could be based on oxidation of VOC in a recirculation thermal
dryer.  As noted elsewhere, EPA has concluded that there is no one
thermal dryer design that will work in all situations found within the
industries utilizing coal preparation and processing plants.  Control of
VOC emissions through activated carbon absorption or regenerative
thermal oxidizers are not utilized on thermal dryers at coal preparation
and processing plants; further, EPA did not have other information
showing that these technologies are adequately demonstrated for use on
coal preparation and processing plant sources.  VOC emissions vary, in
part, due to the variability in volatile contents of the coals being
processed; absent demonstrated control technology, this variability can
not be addressed through add-on technology as it is with variable sulfur
contents of coal.  Thus, EPA believes its decision not to establish VOC
emission limits under Subpart Y at this time is appropriate.

3.3.8	Applicability to Coal Dryers at Cement Manufacturing Plants

Comment:  Several commenters (093, 106, and 123) stated that emissions
from thermal dryers integrated with in-line coal mills at cement
manufacturing plants should not be subject to subpart Y and instead be
subject to the standard for the affected facility as part of the
manufacturing process.  The unique coal processing and handling systems
found at Portland cement plants are best addressed by the Portland
Cement NSPS (40 CFR 60 subpart F) and NESHAP (40 CFR 63 subpart LLL).
The commenters requested that the Subpart Y definition of  “thermal
dryer” in be revised to read “Thermal dryer does not include drying
of coal that occurs intentionally or incidentally in the manufacture of
Portland cement through direct or indirect contact with hot gases
generated by cement manufacturing process units, such as cement kilns,
preheaters, precalciners, or clinker coolers.”  This approach would
both (a) clearly distinguish between separately fired, standalone
thermal dryers that are located at a cement plant, versus thermal dryers
or coal mills that are integrated into a cement manufacturing line, and
(b) avoid any potential confusion about incidental drying of coal that
occurs in the cement-making process. Reasons presented by commenters to
support the requested exemption are summarized below:

In a 1995 determination, EPA stated that when “gases originate in one
affected facility and pass through another affected facility as part of
the manufacturing process, EPA applies the standard for the affected
facility from which the gases are discharged directly into the
atmosphere.” [Applicability Determination 9600082 “Alternative
Monitoring and Opacity Limit Clarification for San Juan Cement
Company,” John B. Rasnic (May 12, 1995)]. However, a year later EPA
qualified this guidance when it concluded that an in-line raw mill was
subject to the subpart F kiln standards stating: This determination
clarifies that for dry process Portland cement plants with an "in-line"
kiln/raw mill configuration, the raw mill does not exist as a separate
affected facility and; hence, the appropriate emission limit is that
which applies to the kiln. [Applicability Determination 9600083;
“Opacity Limitation for ‘In-line’ Portland Cement Plants,” John
B. Rasnic (September 7, 1996)].

Just as emissions from the in-line raw mill in Applicability
Determination 9600083 were subject to NSPS subpart F PM mass and opacity
limitations for cement kilns, so should emissions from an in-line coal
mill at a cement plant where kiln gases are used to heat and dry the
coal be treated as an extension of the kiln and subject to subpart F
NSPS and subpart LLL NESHAP cement kiln PM and opacity limits.  This
approach is consistent with multiple different applicability
determinations provided to Ash Grove by EPA stating that kiln exhaust
gases are subject to the Portland cement NESHAP (LLL) regardless of
whether they are routed through the coal mill prior to discharge to the
atmosphere. See, e.g. Letter from Donald Toensing (EPA Region 7) to
Roger Behrns (Ash Grove Louisville), September 18, 2002.  It is also
consistent with the data that EPA has reviewed in establishing the
proposed Subpart Y limits.  In the absence of data related to emissions
from in-line coal mills, EPA would not have a rational basis supported
by evidence in the record for establishing limits that apply to these
unique gas streams.

As Portland cement plants have striven to increase energy efficiency, a
common plant configuration has been to employ kiln exhaust gas or heated
gas from the plant’s clinker cooler to thermally dry coal before it is
combusted.  Cement kiln exhaust gas is extremely hot and one of the
primary means of improving energy efficiency has been to route this gas
back through the process to extract as much heat as reasonably possible.
 Likewise, the product leaving the kiln (referred to as clinker) will
enter a cooling area where gases are blown through the clinker to
accelerate the cooling process.  In some plants this heated gas is then
used to heat the coal entering the combustion process.  Both kilns and
clinker coolers are affected facilities under subpart F NSPS.  This use
of waste heat from the kiln or the clinker cooler is highly energy
efficient, driving down the combustion emissions, including greenhouse
gas emissions, from the plant as a whole.

Some cement plants have standalone thermal dryers for coal, where the
heat for drying is provided by a dedicated combustion source, e.g., coal
or natural gas.  Those thermal dryers generally should have similar
emissions, and similar possibilities for emissions control, as
comparable-size thermal coal dryers at other facilities.  But where coal
drying is integrated into the cement-making process, through direct or
indirect exposure of the coal to heat in exhaust gases from units such
as cement kilns, preheater/precalciners, or clinker coolers, the
emissions from that coal drying, and the potential for controlling those
emissions, is very different from a standalone thermal dryer.

To the extent that Subpart Y may apply to coal drying that occurs using
waste heat from the manufacture of Portland cement, EPA’s assessments
of control technology and derivation of emission standards under Subpart
Y have not taken into account cement-process-related loadings of SO2,
NOx, and CO.  EPA has not shown, for example, that it would be feasible
for a cement plant to demonstrate compliance with SO2 mass limits or
percent reduction requirements where exhaust gases from coal drying are
combined with cement kiln gases, which include SO2 from fuel consumption
and from raw materials.  Similarly, NOx limits that may be achievable
through combustion controls on a standalone thermal dryer may not be
achievable in exhaust gases mixed with cement kiln gases containing both
fuel NOx and thermal NOx from the cement-making process.

The supplemental proposal would not impose SO2, NOx, and CO limits on
indirect thermal dryers where the source of the heat is subject to
either NSPS under subpart Da, Db, or Dc. Although EPA has not really
explained the basis for that exclusion, it is inferred that EPA believes
the BDT determinations associated with the NSPS for the source of heat
are more appropriate and should be applied.  The same rationale should
be applied to thermal drying that is incidental to cement manufacturing,
and EPA should exclude exhaust gases that are subject to the subpart F
NSPS from being subject to the subpart Y SO2, NOx, and CO limits.

Response:  EPA agrees that in the case of a coal dryer at a cement
manufacturing facility where all of the thermal input is supplied by
cement kiln exhaust or clinker cooler exhaust, the dryer should be
regulated under the appropriate Portland Cement kiln regulations (40 CFR
Part 60, subpart F, and 40 CFR Part 63, subpart LLL).  This would also
imply that any emissions from the thermal dryer are considered as part
of the kiln or clinker cooler emissions.  The final rule’s emissions
limits apply to new, reconstructed, or modified thermal dryers at
Portland cement manufacturing plants in situations where the thermal
input is not supplied by cement kiln or clinker cooler exhaust.  Other
Subpart Y affected facilities located at Portland cement manufacturing
plants (e.g., storage systems, conveyors) also are subject to Subpart Y.

3.3.9	Applicability to Coal Dryers at Steel Manufacturing Plants

Comment:  One commenter (103) requested that thermal dryers fired with
process gases at integrated iron and steel plants be exempted from the
Subpart Y emission limits for SO2, NOx and CO.  Reasons presented by
commenter to support the requested exemption are summarized below.

The pulverized coal injection systems at some integrated iron and steel
plants also burn process gases (i.e., blast furnace gas or coke oven
gas) as the primary fuel in thermal dryers. These process gases are
valuable substitutes for other sources of purchased energy and are
produced on-site.  However, they have lower heating values than natural
gas and must be consumed on-site to be utilized most effectively or be
flared.  As is the case for waste heat, the use of these gases improves
overall plant energy efficiency and reduces greenhouse gas emissions and
should not be discouraged by applying unachievable emission limits when
used for thermal drying of coal.

The use of these process gases for coal drying will not generate any
more emissions than if the gases are combusted elsewhere or flared.
Instead, if the process gases burned for coal drying was replaced
entirely burning natural gas, emissions (mainly NOx and CO) from the
integrated iron and steel plant would actually increase.  Establishing
emission limits for thermal dryers using these process gas fuels will
only serve to discourage their use.

The proposed standards are based on the assumption that thermal dryers
located at traditional mine sites and coal preparation plants are
typically fired with coal, but in the examples noted above, other fuels
are normally used.  At the very least, the rule should include a
provision to allow operators of thermal dryers fired by natural gas,
waste heat, or process gases to apply for a variance upon demonstration
that emissions of SO2, NOx, CO and/or PM are well below the prescribed
standards.  Upon such a demonstration, monitoring requirements for these
pollutants should be reduced or eliminated.

Response:  As noted in the response to comment 3.2, EPA has maintained
that coal preparation and processing plants may be found at industrial
sites such as those described by the commenter.  In the Response to
Comments document for the October 24, 1974, proposal, EPA stated
“[t]he specific coal processing operations regulated by these
standards are affected regardless of whether they are located in coal
liquefaction plants, power plants, coke ovens, etc.” (see
“Background Information for Standards of Performance:  Coal
Preparation Plants; Volume 3:  Supplemental Information.  January 1976.
p. 22).  Thus, EPA has not changed its interpretation.  In addition, EPA
has made no assumptions as to the source of the heat used in the thermal
dryer as the commenter suggests.  However, as noted above for Portland
cement plants, EPA agrees that in the case of an affected source at an
integrated iron and steel manufacturing facility, where the emissions
from the thermal dryer would be considered as part of the blast furnace
or coke oven emissions, the facility should be regulated under the
appropriate steel mill or coke oven NSPS.  As previously explained,
EPA’s intent at this time is to regulate emissions from a thermal
dryer only in circumstances where coal, coal refuse, or residual oil are
used as thermal input.  Thermal dryers that use residual or waste heat
from the combustion of these fuels would only be subject to the PM and
opacity standards.  Indirect thermal dryers for which the source of heat
is subject to SO2, NOX, and/or CO limits under another 40 CFR part 60
subpart would not be subject to the emission limits for SO2 and NOX/CO.
In addition, affected thermal dryers for which all of the thermal input
is supplied by gaseous fuels (e.g., blast furnace gas, coke oven gas,
natural gas) or distillate oil also would not be subject to the emission
limits for SO2 and NOX/CO.

3.4	Subpart Y Coal Processing, Conveying, Storage and Transfer System
Standards

3.4.1	Affected Sources

<IP_ADDRESS>	Coal Unloading Activities	- Subpart Y Proposal Contrary to EPA
Policy

Comment:  Many commenters (085, 086, 088, 095, 107, 108, 112, 115, 117,
and 120) stated that Subpart Y should not be applicable to coal
unloading activities because of previous EPA applicability
determinations and current EPA policy.  Commenters disagree with EPA’s
rationale for its proposal to amend Subpart Y to include coal unloading
activities.  EPA concluded that coal unloading, in general, and truck
dumps, in particular, are NSPS affected facilities at coal preparation
plants based on (1) an “exceptionally strained” interpretation of
the term “conveying equipment,” (2) a guidance manual for agency
inspection of coal unloading at coal preparation plants, and (3) a
document that did not specifically address coal unloading but
nevertheless assumed that activity was regulated by Subpart Y. Review of
the record shows evidence that EPA never intended for coal unloading
activities to be an affected facility at coal preparation plants when
Subpart Y was promulgated. Specific EPA determinations cited by
commenters concerning EPA’s intentions for regulating coal unloading
activities under Subpart Y include the following.

In 1980, EPA’s first review of Subpart Y concluded that that coal
unloading was not a Subpart Y affected facility.

In 1995, EPA Region VIII advised the Wyoming Department of Environmental
Quality that “truck coal dump operations are not affected facilities
subject to the NSPS Subpart Y regulations.”

In 1998, EPA Headquarters published an interpretative ruling in the
Federal Register stating that “coal unloading that involves conveying
coal to plant machinery is regulated under Subpart Y” (63 FR 53288,
dated October 05, 1998).  EPA Headquarters “use[d] the term “coal
unloading” to encompass “coal truck dumping” and “coal truck
unloading” as well as dumping or unloading from trains, barges, mine
cars, and conveyors.”  EPA explained its reasoning behind that 1998
interpretation, as follows: section 60.251(g) defines “coal processing
and conveying equipment” as “any machinery used to reduce the size
of coal to or remove coal and refuse from the machinery.  This includes,
but is not limited to, breakers, crushers, screens, and conveyor
belts.”  The key phrases are “the equipment used to convey coal to .
. . machinery” and “but not limited to.”  Although the equipment
involved in coal unloading varies from plant to plant (the definition is
written broadly enough to accommodate the differences), what is
important is that the equipment performs the function of conveying.  It
should be noted that if the coal is unloaded for the purpose of storage,
then the unloading activity is not an affected facility under Subpart Y.
 The coal must be directly unloaded into receiving equipment, such as a
hopper, to be subject to the provisions of Subpart Y (63 FR 53289).

Subpart OOO explicitly excludes truck dumping from NSPS control
requirements (section 60.672(d)).  Subpart OOO was just recently
revised, 74 FR 19294 (April 28, 2009), and it continues to contain that
NSPS-exclusion for truck dumping.  Thus, in the absence of
(1) representative data for achievable levels of controlled emissions
from coal unloading and (2) associated documentation that the costs of
such controls are reasonable, the obvious inference is that coal
unloading should also remain excluded from NSPS.

Response:  As commenters noted, in 1998 EPA issued an interpretative
ruling that states that “coal unloading” operations (which include
both truck and rail car dumping) are regulated under subpart Y.  This
interpretative ruling has not been changed in the intervening years and,
thus, remains in effect.  In the interpretative ruling, EPA concluded

…that coal unloading that involves conveying coal to plant machinery
fits within the definition of “coal processing and conveying
equipment.”  40 CFR 60.251(g) defines “coal processing and conveying
equipment” as “any machinery used to reduce the size of coal or to
separate coal from refuse, and the equipment used to convey coal to or
remove coal and refuse from the machinery.  This includes, but is not
limited to, breakers, crushers, screens, and conveyor belts.”  The key
phrases are “the equipment used to convey coal to * * * machinery”
and “but is not limited to.”  While the “equipment” involved in
coal unloading varies from plant to plant (the definition is written
broadly enough to accommodate the differences), what is important is
that the equipment perform the function of conveying...The coal must be
directly unloaded into receiving equipment, such as a hopper, to be
subject to the provisions of NSPS Subpart Y.  (see 63 FR 53288.)

Thus, EPA interprets coal unloading into the first hopper
“downstream” from any form of transportation to be the beginning of
the “coal preparation plant.”

As the standards under Subpart Y are based on data obtained from subject
facilities, the comparisons with subpart OOO have no meaning.  As
discussed below in response to comment <IP_ADDRESS>, the central question is
whether the standard set in this rule is appropriate not whether a
standard set in a different rule was appropriate.  Much of commenters’
reasoning is based upon past applicability determinations that said
unloading were not subject to Subpart Y.  Such determinations were based
on interpretations of the current rule language at the time.  Thus, the
determinations do not speak to Agency intent or policy regarding whether
such regulation would be appropriate.  Further, as noted, they were
superseded by the 1998 interpretation, which was published in the
Federal Register.

<IP_ADDRESS>	Coal Storage Piles

<IP_ADDRESS>.1	Authority to Regulate Coal Storage Piles under Subpart Y

Comment:  Many commenters (086, 091, 094, 110, 114, and 117) stated that
EPA does not have the authority to regulate coal storage piles under 40
CFR 60. Section 60.1 provides that the provisions of 40 CFR 60 “apply
to the owner or operator of any stationary source which contains an
affected facility... .”  Stationary source is defined in section 60.2,
consistent with 42 USC 7411, as including any building, structure,
facility or installation.  Although it is not clear that a coal pile
constitutes a building, structure, facility or installation, if it does,
under section 60.1 the stationary source must also contain an affected
facility.  Affected facility is defined in section 60.2 as “with
reference to a stationary source, any apparatus to which a standard is
applicable.” This latter definition presents a substantial problem.
If EPA wishes to regulate coal storage piles under 40 CFR 60 as part of
a stationary source, the coal storage piles must be an apparatus.  At
many facilities which manage coal, coal storage piles are nothing more
than what the name suggests: piles of coal. These piles often have no
walls, no floor surfaces, and no equipment associated with their use.
Although the term “apparatus” is an undefined term under 40 CFR 60,
we do not believe that a pile of minerals mined from the earth and
stored on the earth constitutes an “apparatus” which subjects the
pile to regulation under 40 CFR 60.  Although the authority may not
exist to regulate coal storage piles under 40 CFR 60, this would not
leave such storage piles unregulated.  In many states, fugitive
emissions from coal piles are regulated under State fugitive emissions
limitations which are often incorporated into state implementation
plans, and we do not challenge those regulations in this rulemaking.

Response:  EPA disagrees with commenters’ assertion that a coal pile
cannot be an affected facility under 40 CFR 60.  Commenters correctly
noted that the term “affected facility” is defined in section 60.2
to mean “with reference to a stationary source, any apparatus to which
a standard is applicable.”  The commenters also correctly note that
the term “apparatus” is undefined in 40 CFR 60, and an agency’s
interpretation of its own regulation is granted substantial deference
(see, e.g., Auer v. Robbins, 519 U.S. 452, 461, 1997).

The commenters do not offer a definition of “apparatus” but appear
to suggest that to be an “apparatus” a coal pile would need to have
“walls, floor surfaces, or equipment associated with their use.”
The commenters, however, offer no support for this assertion, and EPA
does not believe such a limited definition of “apparatus” would be
reasonable or consistent with the plain English meaning of the word.
Further, the Courts stated “In designating what will constitute a
facility in each particular industrial context, EPA is guided by a
reasoned application of the terms of the statute it is charged to
enforce.”  ASARCO Inc. v. EPA, 578 F.2d 319, 324 n.17 (1978).  In this
case, because coal storage piles are significant sources of emissions
and are physically located at coal preparation and processing plants,
EPA believes it is reasonable in this context, to determine that they
are facilities that can be subject to regulation.

The dictionary definition of the word “apparatus” also supports
EPA’s approach.  The word “apparatus” has a very broad meaning and
can include tangible items such as equipment, tools and materials as
well as intangible items such as activities and functions.  The Random
House College Dictionary: Revised Edition defines the word
“apparatus” as follows:

1. a group or aggregate of instruments, machinery, tools, materials,
etc. intended for a specific use.  2. any complex instrument or machine
for a particular purpose.  3. any system of activities, functions etc
directed toward a specific goal: the apparatus of government.  4. a
group of structurally different organs performing a particular function.

Because a coal pile constitutes “a group or aggregate of . . .
materials . . . intended for a specific use,” it qualifies as an
“apparatus” under the first definition of the word.  Furthermore,
given the broad meaning of the term “apparatus,” EPA believes it
would not be reasonable to interpret this term to limit the scope of the
definition of “affected facility” to exclude a significant part of
the coal preparation and processing plant that may have significant
emissions.

In addition, although commenters do not actually argue that a coal pile
does not constitute a stationary source because it is not a building,
structure, facility, or installation, EPA notes that there can be no
doubt that a pile of coal does in fact qualify as a stationary source as
that term is defined in 42 USC 7411 and section 60.2.  Stationary source
is defined in 42 USC 7411 as including “any building, structure,
facility or installation which emits or may emit any air pollutant.”
This same definition appears in section 60.2.  The terms building,
structure, facility, or installation, are not defined although section
60.2 does contain definitions for “affected facility” and
“existing facility.”  In some instances, the regulated affected
facility may be a portion or a part of a stationary source, but not the
entire source.  In other circumstances, however, a stationary source may
also be an affected facility.  Because, as noted above a coal pile can
be an affected facility it necessarily also can be a facility within the
definition of stationary source.  In addition, the terms installation
and structure are very broad and not limited to things that have walls,
floor surfaces or dedicated equipment.  For these reasons, commenter’s
assertion that coal piles cannot be regulated under 40 CFR 60 is without
support.

<IP_ADDRESS>.2	Site-specific Coal Pile Emission Characteristics

Comment:  Several commenters (091, 099, 109, 117, and 119) stated that
coal piles should not be regulated under Subpart Y because of the
diverse conditions affecting emissions from coal storage piles that
could be encountered at each coal preparation plant site.  Among the
site-specific factors for open coal storage piles that will vary widely
from site to site are the following: ambient temperature, precipitation,
meteorology, wind speed, and geography.  Therefore, a uniform NSPS is
not be appropriate for coal piles and that fugitive coal dust emissions
from coal piles should be addressed by case-by-case determinations in
individual permit proceedings.  In addition, as EPA has recognized in
its initial proposal, and as we have discussed above, fugitive emissions
will depend on coal properties and coal rank.

Response:  EPA does not agree with the commenters that coal piles should
not be regulated under subpart Y.  Such sources were apparently included
in the October 1974 proposed rule (i.e., there was no specific
exclusion).  A comment was received indicating that no fugitive dust
control options were available for open storage piles other than water
sprays and that these were not effective on windy days.  EPA
subsequently excluded open storage piles from regulation in the final
rule (January 1976).  However, EPA has now identified additional control
measures, beyond simple water sprays, that may be utilized on coal piles
and that address the concerns noted by commenters.  EPA is establishing
work practice standards instead of standards of performance for coal
piles.  Owners/operators are required to develop a fugitive coal dust
emissions control plan to control emissions from the coal piles, and the
plan requirements established by EPA provide adequate flexibility for an
owner/operator to tailor their plan to address site-specific factors.

Comment:  One commenter (109) stated that EPA should limit the inclusion
of coal storage piles and roadways to new sources.  The variety of
methods that EPA has proposed to be included in a fugitive dust plan
(including wet or chemical suppression, fogging, sweeping, etc) are
workable and are in fact being required in many cases by state-level
permitting authorities for new facilities.

Response:  As explained in the response to comment <IP_ADDRESS>, EPA is
withdrawing its proposed requirements for roadways based on its
determination that the requirements of SMCRA are sufficient to address
air emissions from roadways that may be found within a coal preparation
and processing plant at mine sites.  EPA believes that coal moving
operations, once the coal enters the “coal preparation plant,”
whether located at a mine sit or at end-user facilities, will be by
conveyor rather than by truck.  Also, as explained in the response to
comment <IP_ADDRESS>, EPA agrees with the commenters that open storage piles
are always changing and, for purposes of subpart Y, we do not consider
the routine addition and removal of coal to be a physical change or a
change in the method of operation.  However, changes to the equipment
used in loading, unloading, and conveying operations of open storage
piles are among the things that can be assessed in order to determine
when an open storage pile has been reconstructed or modified.  Thus, in
the final rule, EPA defines “open storage pile” to mean “any
facility, including storage area, that is not enclosed that is used to
store coal, including the equipment used in the loading, unloading, and
conveying operations of the facility.”

<IP_ADDRESS>.3	Inclusion of Open Storage Piles in Definition of “Coal
Storage System”

Comment:  Several commenters (087, 099, and 119) stated that inclusion
of open storage piles in the proposed definition of “coal storage
system” creates implementation problems and uncertainty.  EPA could
instead create a new affected facility for open coal storage piles which
should be defined, and amend proposed section 60.254 to include the
specific work practice standards that apply only to open storage piles.

The proposed regulatory language can be read to require open storage
piles to comply with the 5 percent opacity limit.  The proposed 5
percent opacity standard in proposed section 60.254(b)(1), applies to
“any coal processing and conveying equipment, coal storage system, or
coal transfer and loading system processing coal constructed,
reconstructed, or modified after April 28, 2008 . . . .” (proposed
section 60.254(b).  As proposed in section 60.251 coal storage system
means “any facility used to store coal,” and section 60.254 fails to
exempt open coal storage piles from the opacity standard.

EPA should clarify what “unit” means in the context of coal storage
piles.  Are all coal storage piles within a power plant a single
“unit?”  Are short-term and long-term coal storage piles separate
“units?”  Are two adjacent mounds of coal deemed to be separate
“units?” How much space or differentiation between adjacent coal
piles would constitute them being deemed to be more than a single
“unit?”

The preamble states that because EPA is proposing to include open
storage piles as an affected facility, the loading, unloading, and
conveying operations of open storage piles would be included in the
fugitive dust emissions control plan, but not subject to opacity limit.
However, the definition of “coal storage system” does not include
loading, unloading and conveying operations.  EPA must clarify in the
final rules whether those activities must be included in the plan.

Response:  As explained eslewhere, EPA is promulgating a work practice
standard instead of a standard of performance for coal piles. As noted
by the commenter, the preamble to the supplemental proposal states that
the loading, unloading, and conveying operations of open storage piles
also would be covered under the fugitive dust emissions control plan,
but not subject to an opacity limit (74 FR 25312).  The regulatory text
has been revised to make it clear that open storage piles and associated
loading, unloading, and conveying operations are required to be
addressed under a fugitive coal dust emissions control plan and are not
subject to opacity limits.  Each storage pile, whether short-term or
long-term, is considered an affected facility under Subpart Y.
Individual open coal storage piles (“affected facilities”) would be
defined as having a separate stacking system, regardless of the space
between the piles.

<IP_ADDRESS>.4	Coal Piles Loaded in Trucks, Railcars, and Ships

Comment:  Several commenters (087, 099, 119, and 126) agree that piles
of coal that have been loaded into trucks, railcars, and/or ships should
not be subject to the Subpart Y control requirements for open storage
piles.  In contrast, several other commenters (096, 100, and 113)
disagree with EPA’s stated rationale for proposing this exclusion.
One commenter (096) provided the following reasons: 1) EPA has not
identified any information or data to its statement that fugitive dust
emissions from these sources are not significant, 2) it is not
economically infeasible to require cover the coal or chemical
encrustation on loaded trucks, railcars, and ships because operators may
choose to use these controls to comply with state and local regulations
or the desire to minimize the loss of coal while in transit, and 3) EPA
did not consider the use of alternate work practice standards already
identified as appropriate for open piles, including the use of wet
suppression.  EPA should recognize that the owners and operators of coal
preparation plants–as the ones who determine the placement of coal
into trucks, railcars, and ships, and as the ones who initiate the use
of any appropriate controls–are uniquely situated to take the steps
most effective at reducing or limiting fugitive dust emissions from
these sources once they leave the facility.  Although some of the
emissions from piles loaded into trucks, railcars, and ships may occur
beyond the boundaries of the coal preparation plant, the extent of these
emissions depends on actions taken at the coal preparation plant.
Accordingly, these emissions are directly traceable to the coal
preparation plants and responsibility should rest with the owners and
operators of these plants.  The alternative–refusing to assign
responsibility of these emissions to any party–is unacceptable and
inconsistent with EPA’s mandate to protect the public health and
welfare.

Response: EPA is not addressing at this time emissions from the sources
noted by the commenters because we found any such regulation to be
impractical to enforce (particularly with regard to interstate
shipments).  Further, based on available data  emissions from these
sources while at the coal preparation and processing plant have not been
shown to be significant and, at this time, EPA has no data on emissions
from such sources while enroute.

<IP_ADDRESS>	Coal Preparation Plant Roadways

Comment:  Many commenters (082, 085, 086, 087, 088, 093, 095, 107, 109,
112, 114, 115, 120, 123, and 126) requested clarification regarding the
plant roadways to which EPA intends Subpart Y to apply.  EPA does not
clearly explain what it means for a roadway to be “associated” with
a preparation plant.  Nor does EPA define the term “haul road.”  EPA
should clarify that “roadways” such as haul roads that do not leave
the plant property are not subject to Subpart Y. EPA needs to clearly
define where the coal preparation plant begins and where the coal mine
ends.  Subpart Y is applicable only to affected facilities of a coal
preparation plant.  EPA should clarify that no facilities at a coal
mine, even if the mine is contiguous to the property of the preparation
plant, are covered under the provisions of Subpart Y.  EPA must clearly
define the term “haul roads” and should not, regulate under Subpart
Y any roadways outside of the preparation plant.  Other commenters (096
and 113) disagree with EPA’s proposal to exclude roadways that do not
leave the property (e.g., haul roads at coal mines) from being subject
to Subpart Y for the following reasons with specific examples cited: (1)
road wetting can be accomplished in a manner that is easy to adjust with
the re-routing of haul roads, including the use of water trucks and
temporary sprayers; (2) certain coal preparation plants are already
required to abate dust on their internal haul roads; (3) some states
currently impose dust suppression requirements on all roads associated
with coal preparation plants.

Response:  As noted in the response to Comment 3.2 above, EPA, in both
the air and water offices, has historically maintained the concept that
activities undertaken at or near the active mine face (“active mining
area”) would not be part of the “coal preparation plant” and that
“coal preparation” involves separation of coal from impurities
(i.e., “breaking” or “crushing”).  As discussed in the response
to the comment in section <IP_ADDRESS>.1 above, EPA interprets the
“beginning” of the “coal preparation plant” to be the first
hopper (i.e., “drop point”) for receipt of coal from any form of
transportation.  Thus, any haul roads between the “active mining
area” and the first hopper of the “coal preparation plant” would
not be subject to Subpart Y; rather they would be subject to the
requirements of SMCRA or the specific State.  Similarly, roads occurring
after the coal has been loaded for distribution would not be subject to
Subpart Y.

Under the definition of “surface coal mining operations” contained
in 30 CFR 70.5 (SMCRA), operations conducted within a coal preparation
plant are covered under SMCRA:

(a)  Activities conducted on the surface of lands in connection with a
surface coal mine…the products of which enter commerce or the
operations of which directly or indirectly affect interstate commerce.
Such activities include…the cleaning, concentrating, or other
processing or preparation of coal.  Such activities also include the
loading of coal for interstate commerce at or near the mine site
(emphasis added).

Such operations also include roads (under 30 CFR 701.5).  30 CFR 780.15
requires the following:

(a)  For all surface mining activities with projected production rates
exceeding 1,000,000 tons of coal per year and located west of the 100th
meridian west longitude, the application shall contain an air pollution
control plan which includes the following:

(1)  An air quality monitoring program to provide sufficient data to
evaluate the effectiveness of the fugitive dust control practices
proposed under paragraph (a)(2) of this section to comply with Federal
and State air quality standards; and

(2)  A plan for fugitive dust control practices as required under 30 CFR
816.95.

(b)  For all other surface mining activities the application shall
contain an air pollution control plan which includes the following:

(1)  An air quality monitoring program, if required by the regulatory
authority, to provide sufficient data to evaluate the effectiveness of
the fugitive dust control practices under paragraph (b)(2) of this
section to comply with applicable Federal and State air quality
standards; and

(2)  A plan for fugitive dust control practices, as required under 30
CFR 816.95.

30 CFR 816.95(a) specifies:

All exposed surface areas shall be protected and stabilized to
effectively control erosion and air pollution attendant to erosion.

30 CFR 816.150 provides some additional requirements:

(b)  Performance standards.  Each road shall be located, designed,
constructed, reconstructed, used, maintained, and reclaimed so as to:

(1)  Control or prevent erosion, siltation, and the air pollution
attendant to erosion, including road dust as well as dust occurring on
other exposed surfaces, by measures such as vegetating, watering, using
chemical or other dust suppressants, or otherwise stabilizing all
exposed surfaces in accordance with current, prudent engineering
practices…

(e)  Maintenance.  (1)  A road shall be maintained to meet the
performance standards of this part and any additional criteria specified
by the regulatory authority.

Thus, SMCRA covers fugitive dust emissions from roads at coal
preparation and processing plants at mine sites and requires a fugitive
dust plan and other requirements to control air pollution from such
sources (through similar measures as were included in the supplemental
proposal for Subpart Y).  EPA believes that coal moving operations, once
the coal enters the “coal preparation plant,” will be by conveyor
rather than by truck.  Therefore, EPA believes that the requirements of
SMCRA are sufficient to address air emissions from roadways that may be
found within a coal preparation and processing plant at mine sites.  For
coal preparation and processing plants at end-user facilities, EPA
believes that, again, once the coal enters the “coal preparation
plant,” coal moving operations will be by conveyor rather than by
truck.  Therefore, EPA is withdrawing its proposed requirements for
roadways.

Where fugitive coal dust emissions control plan requirements under
Subpart Y for open storage piles overlap requirements under SMCRA or
State regulations, those sources may submit the more stringent of the
required monitoring plans to the Administrator or delegated authority as
required by the final rule.

<IP_ADDRESS>	Coal Sampling Systems

Comment:  Many commenters (085, 088, 095, 107, 112, 115, and 120)
requested that coal sampling systems located at coal preparation plants
be specifically exempted from Subpart Y. Coal sampling systems obtain
representative samples of coal as delivered.  Generally, the sampler
cuts across a conveyor belt through a falling stream of coal at a
transfer point on an interval determined by time or weight of coal on
the conveyor.  The cut is transferred to a small crusher and the size of
the sample is reduced by a series of riffling devices.  The remaining
coal from a cut is transported back onto the main conveyor.  To protect
coal sampling system equipment at coal processing plants from the
weather, such equipment is typically is located in a building or
structure, or otherwise covered on all sides.  Very little dust is
generated by coal sampling systems because the conveyors, crushers and
rifflers in the system operate at low velocity, the system as a whole
operates intermittently, and the throughput is low.

Response:  As explained in the response to comment <IP_ADDRESS>, coal
sampling systems at affected facilities have been subject to the
existing Subpart Y requirements since they were originally promulgated
in 1976.  Also, an affected facility enclosed within a building or
structure would be considered to be in compliance if the building in
which it is enclosed is in compliance with the standard.  For these
reasons, EPA does not believe it would be appropriate, in this review,
to add the exemption requested by commenters.

3.4.2	Relationship of Subpart Y Requirements to Other Rules

<IP_ADDRESS>	NonMetallic Mineral Processing NSPS (40 CFR 60 subpart OOO)

Comment:  Many commenters (085, 088, 095, 107, 112, 115, and 120) stated
that because of the inherent similarities in the basic characteristics
of facilities used for coal preparation and for nonmetallic mineral
processing, and recognizing the common use of the same technologies to
control PM emissions from same types of facilities the overall format
and requirements for control of PM emissions from coal processing in
Subpart Y should be consistent with the relevant requirements under
subpart OOO for control of PM emissions from nonmetallic mineral
processing.  One commenter (095) presented a list of the specific
provision citations from subpart OOO that the commenters believe are
relevant and should also be adopted for coal preparation plants subject
to the Subpart Y amendments.  Reasons presented by the commenters are
summarized below.

Coal is a nonmetallic mineral.

Subpart OOO and Subpart Y regulate the same types of processing
equipment and operations.

Even though the magnitudes of the PM emissions from subpart OOO
facilities may not be equivalent to levels of PM emissions from
comparable Subpart Y facilities, the origins of those emissions are the
same at both types of facilities and the controls of those emissions
employ the same technologies.

Predominant type of fugitive emissions controls at both Subpart Y and
subpart OOO facilities is wet suppression.

The emissions data base used by EPA to support development of standards
for subpart OOO is extensive while the emissions data supporting Subpart
Y is very limited.

Response:  As the Courts have explained, “the Administrator is not
required to present affirmative justifications for different standards
in different industries. Inter-industry comparisons of this kind are not
generally required, or even productive; and they were not contemplated
by Congress in this Act.  The essential question is whether the mandated
standards can be met by a particular industry for which they are set,
and this can typically be decided on the basis of information concerning
that industry alone. . . .  It would be unmanageable if, in reviewing
the [challenged] standards, the court should have to consider whether or
not there was a mistake in [a different source category’s] standard .
. . . ” Portland Cement Ass’n v. Ruckelshaus, 486 F.2d 375, 389
(D.C. Cir. 1973).

The standards established in this rulemaking are based on data regarding
emissions and control technologies applied to Subpart Y facilities while
the subpart OOO rule was based on data from subpart OOO facilities.  The
fact that the similar types of processing equipment and operations are
used by the two source categories does not mean that the emissions from
the source categories are comparable.  In fact, commenters objected to
EPA’s use of subpart OOO data to develop the Subpart Y amendments
proposed on April 28, 2008.  They argued that EPA did not demonstrate
that use of subpart OOO data were representative of the coal preparation
industry.  Further, the commenters characterized that proposed
rulemaking as having analytical flaws and data deficiencies.  The May
27, 2009 supplemental proposal was based on data and information for
coal preparation and processing operations.  When conducting a BDT
analysis, EPA considers many factors unique to the source category
including the specific materials involved, the control technologies
employed, the emission levels achieved, and the cost of controls.  For
these and other reasons, the standards established for one source
category may differ from those established for a different source
category.

<IP_ADDRESS>	Surface Mining Control and Reclamation Act (SMCRA)

Comment:  Two commenters (095 and 117) stated that EPA’s proposed
Subpart Y fugitive dust control requirements as applied to surface coal
mines are duplicative of  existing regulatory programs.  In particular,
under SMCRA, coal mine operators must control fugitive dust through a
plan submitted as part of the SMCRA permitting process.  Requirements
under SMCRA provides the U.S. DOI authority to require mine operators to
"stabilize and protect all surface areas ... to effectively control
erosion and attendant air and water pollution." §SIS(b)(4), 30 U.S.C.
§126S(b)(4) (1988); see also §SIS(b)(l7), 30 U.S.C. §126S(b)(l7)
(1988).  Under this authority, DOI has promulgated extensive
regulations, requiring, for example, that all surface coal mining permit
applications include a plan for fugitive dust control and an air quality
monitoring program to evaluate its effectiveness. 30 CFR §780.1S
(1990).  In addition, haul roads must be located, designed, constructed,
used, maintained, and reclaimed so as to "[c]ontrol or prevent erosion
... , including road dust as well as dust occurring on other exposed
surfaces, by measures such as vegetating, watering, using chemicals or
other dust suppressants." Id. §816.1S0(b)(I).

Response:  As noted above in the response to comment <IP_ADDRESS>, it is not
EPA’s intent to regulate sources prior to the “coal preparation
plant” itself.  Further, EPA is withdrawing its requirements for
roadways.  Where requirements for open storage piles overlap, those
sources may submit the more stringent of the required monitoring plans
to the Administrator or delegated authority as required by the final
rule.

3.4.3	BDT Determination

Comment:  Many commenters (085, 088, 099, 107, 112, 115, 119, and 120)
acknowledged EPA’s decision in the supplemental proposal to add
fogging systems and passive enclosure dust containment systems to its
list of BDT for coal processing and conveying equipment, but stated that
EPA’s BDT determination still failed to meet the requirements of CAA
§ 111.  Additional commenters (095 and 117) also disagreed with EPA’s
finding of chemical suppression to be BDT for coal handling equipment
processing bituminous coal, stating that EPA’s current BDT approach of
focusing only on emission control systems with the highest control
efficiency is an inappropriate, unjustified departure from its prior
technology assessments for coal preparation plants.  EPA’s evaluation
of technologies for control of fugitive emissions from coal-handling
should have included wet suppression.  Further, EPA must explain why it
has either rejected or ignored Peabody Energy’s compelling comparison
of wet suppression costs and chemical suppression costs.  We are unaware
of any other credible comparison of those respective costs having been
submitted to EPA.  Consequently, the record demonstrates that cost
considerations favor the use of wet suppression instead of chemical
suppression for controlling fugitive emissions from preparation
facilities at coal mines.

Response:  As pointed out by the commenters, EPA has added fogging
systems and PECS as technologies representative of BDT for coal-handling
equipment processing subbituminous and lignite coals (fabric filters and
wet extraction scrubbers also are considered representative of BDT).  As
noted in the supporting documentation (see EPA-HQ-OAR-2008-0260-0083,
pp. 1-2), EPA has reviewed our determination of chemical suppressants as
BDT for coal-handling equipment processing bituminous coal.  However, as
also noted in the support document, an owner/operator may use any
combination of controls at a particular site as long as the requirements
of subpart Y are met.  With respect to Peabody Energy’s comparison of
wet suppression and chemical suppression costs, their estimates indicate
that the incremental cost of chemical suppression as compared to wet
suppression is $4,400 per ton of PM removed.

3.4.4	PM Emission Limits

<IP_ADDRESS>	Applicability of PM Emission Limits

Comment:  Several commenters (099, 107, 119, and 115) support of EPA’s
decision to limit applicability of the PM emission limit to mechanically
vented coal handling equipment.

Response:  EPA appreciates the commenters’ support of its approach.

<IP_ADDRESS>	Selection of Proposed PM Emission Limit Level

Comment:  Many commenters (093, 099, 107, 115, 117, 123, and 119)
support EPA’s decision to increase the PM emission limit for
mechanically vented coal handling equipment to 0.010 gr/dscf in the
supplemental proposal.  In response to the EPA’s request in the
supplemental proposal notice for additional comment on a PM standard
between 0.0090 gr/dscf and 0.011 gr/dscf, one commenter (099) stated
that EPA’s analysis in a memorandum for the subpart OOO rule (using
essentially the identical data base) concluded that a PM level of 0.010
gr/dscf would be achieved only 86 percent of the time.  Only a few
months ago EPA finalized a PM NSPS of 0.014 gr/dscf in the subpart OOO
rule).  Given EPA’s data and conclusions, any additional revisions to
the PM emission limit level should result in a higher PM limit, not
lower one.  In contrast, one commenter (113) stated that the proposed PM
limit should be at the level proposed in the original Subpart Y
amendment proposal of 0.011 g/dscm.  This limit is feasible, and it will
be easy for operators to meet them if the coal-handling system is
entirely enclosed.  The PM limit should apply regardless of whether the
coal-handling system is vented.  If the system is entirely enclosed,
then it should not be difficult for the operator to meet the PM limit.
If, however, there is a crack in the enclosure or an operator fails to
install a proper enclosure, the PM limit and monitoring will catch that
error and prevent potential excess emissions.

Response:  The PM emission limit of 0.023 g/dscm; 0.010 gr/dscf for
mechanically vented coal-handling equipment is supported by the data
obtained from coal preparation and processing plants and is applicable
only to vented sources.  Sources that are not vented would not be
subject to the mass PM limit, only the opacity limits.

3.4.5	Opacity Standards

<IP_ADDRESS>	Opacity Standards for Open Storage Piles and Roadways

Comment:  Many commenters (085, 086, 087, 088, 091, 093, 095, 098, 099,
107, 109, 112, 115, 116, 119, 123, and 120) stated that establishing
opacity standards for open coal storage piles and roadways would be
impractical and unnecessary.  In contrast, one commenter (096) states
coal storage piles can be enclosed and the captured fugitive dust then
vented to a fabric filter (see Section <IP_ADDRESS>) from which the emissions
are vented from a stack allowing opacity readings to be performed.
Therefore, opacity standards for coal storage piles can be established.
Reasons cited by individual commenters for not establishing opacity
standards for these sources include:

Fugitive dust from open storage piles and roadways are already regulated
under SMCRA by US Office of Surface Mining so duplicative regulations
under Subpart Y are unnecessary.

PM emissions from coal piles are already subject to state fugitive dust
regulations (whether applicable to storage piles in general or coal
piles in particular) and, in many cases, State air permits.  There is no
rationale for imposing fugitive dust control requirements on coal
storage piles and roadways because they are already controlled by
existing-source regulations and do not present significantly different
opportunities for work practice controls than do existing coal storage
piles and roadways. (093 and 123)

The nature of fugitive dust from open storage piles and roadways does
not lend them to application of the Method 9 test procedure requiring
6-minute average opacity readings.

Determining a reasonable opacity limit would be very complicated because
of the numerous and disparate factors that might influence emissions
from any particular pile, such as coal types and varieties, pile shapes,
pile compaction, throughput rates, and traffic.

By the very nature of open storage piles, activity is intermittent and
during times when activities such as stacking or reclaiming are being
done, fugitive emissions will likely be greater than 5 percent.

It is difficult and extremely expensive to measure actual PM emissions
from individual open storage piles and many States require affected
facilities to hire consultants to conduct Method 9 opacity testing.
Hiring consultants to perform opacity observations is not cost effective
given the size of open storage piles, which constantly fluctuate in
volume and shape, and the steep fees charged by such consultants.

The EPA Visible Emissions Field Manual for Method 9 training admits that
opacity observations from open storage piles are very difficult to
perform, and it is not practical to perform them for compliance on a
regular basis.

Response:  As explained in the response to comment <IP_ADDRESS>, SMCRA covers
fugitive dust emissions from activities conducted on the surface of
lands in connection with a surface coal mine and requires a fugitive
dust plan and other requirements to control air pollution from such
sources.  Further, EPA believes that coal moving operations, once the
coal enters the “coal preparation plant,” will be by conveyor rather
than by truck and, therefore, that the requirements of SMCRA are
sufficient to address air emissions from roadways that may be found
within a coal preparation plant at mine sites.  For coal preparation
plants at end-user facilities, EPA believes that, again, once the coal
enters the “coal preparation plant,” coal moving operations will be
by conveyor rather than by truck.  Thus, EPA is withdrawing its proposed
requirements for roadways.

Where fugitive dust emissions control plan requirements under Subpart Y
for open storage piles overlap requirements under SMCRA or State
regulations, those sources may submit the more stringent of the required
monitoring plans as required by the final rule.

With respect to monitoring the effectiveness of fugitive dust control
measures used on open storage piles, EPA supports its previous
determination that the size of open storage piles makes the use of
Method 9 opacity observations unreasonable in many situations.  For this
reason, EPA has concluded that it is not feasible to prescribe or
enforce a standard of performance and that work practice standards are
appropriate.

<IP_ADDRESS>	Proposed Opacity Limit Level

<IP_ADDRESS>.1	Insufficient Representative Data

Comment:  Many commenters (085, 086, 088, 095, 107, 112, 115, 116, and
120) stated that EPA has insufficient representative data of achievable,
controlled emissions to set an appropriate opacity standard.  With the
lone exception of a single 3-hour Method 9 test of a rotary car dumper,
not at a preparation plant but at a marine terminal, the background
information documents for Subpart Y development contain no data specific
to fugitive emissions from coal unloading.  EPA cannot credibly argue
that opacity data from a single Method 9 test of a rotary car dumper
satisfies the CAA section 111 mandate for obtaining data on
representative levels of achievable, controlled emissions from coal
unloading.  EPA cannot defend the imposition of an emissions standard on
a facility for which EPA has no representative emissions information.
One commenter (095) submitted with their comments additional data from
recently performed Method 9 observations of visible emissions from a
number of different coal preparation plants around the country, and that
EPA did not properly evaluate wet suppression.  The commenters state
that these data are more representative of achievable emissions from
coal preparation and support setting a higher opacity limit under
Subpart Y for coal-handling operations at coal preparation plants.

Response:  EPA disagrees with the commenters about the quantity of
available data.  A review of the data set used indicates that there are
a number of unloading operations included (and not at marine terminals)
[PM/Opacity memorandum, May 2009]. A review of Commenter 095’s
submitted data indicates support for the opacity level established.

<IP_ADDRESS>.2	Continuous Achievability of Opacity Limit

Comment:  Many commenters (084, 085, 086, 088, 095, 099, 107, 112, 115,
119, and 120) stated the data used by EPA does not demonstrate the
continuous achievability of the proposed opacity limit.  The
promulgation of NSPS based upon inadequate proof of achievability would
defy the Administrative Procedure Act’s mandate against action that is
arbitrary, capricious, an abuse of discretion, or otherwise not in
accordance with the law. National Lime Ass’n v. EPA, 627 F.2d 416, 430
(D.C. Cir. 1980).

Response: I n the May 27, 2009, supplemental proposal, EPA requested
comment on whether an opacity limit of less than 10 percent is more
appropriate than the proposed limit of 5 percent.  We also requested
comment on whether the 5 percent limit is achievable on a long-term
basis for all Subpart Y coal-handling facilities under all operating
conditions and whether the limit provides an adequate compliance margin.
 As we pointed out in supporting documentation (see
EPA-HQ-OAR-2008-0260-0083, pp. 3-4), the data used to establish the
supplemental proposal’s 5 percent opacity level were primarily from
initial compliance tests, and the reported highest 6-minute average
opacity reading was 5 percent for a recently installed facility.  Data
for coal-handling facilities submitted by commenters in response to the
supplemental proposal indicate that 60 percent of the highest 6-minute
average opacity readings are less than 10 percent.  Upon reconsideration
of EPA’s data and consideration of the public comments and supporting
data, EPA has determined that an opacity limit of less than 10 percent
is more appropriate for all coal-handling equipment.  An opacity limit
of 10 percent will allow for control equipment degradation, adverse
conditions, and variability that would not be reflected in initial
compliance tests.  Thus, the final rule requires coal handling
facilities to maintain opacity levels of less than 10 percent.

<IP_ADDRESS>.3	Selection of Proposed Opacity Limit Level

Comment:  One commenter (126) stated that the WDEQ requires PECs and
fogging systems to be operated and maintained so the system enclosures
exhibit no visible emissions as determined by Method 22.  The WDEQ’s
experience with fabric filters and wet extraction scrubbers shows
similar performance levels can be achieved through a well maintained
system.  Therefore, commenter supports an opacity limit of no greater
than 5 percent.  A second commenter (113) stated that the proposed
opacity limit should have been kept at the level proposed in April 2008
of “less than 5 percent.”  This limit is feasible, and it will be
easy for operators to meet it if the coal-handling system is entirely
enclosed.  Commenter 117 agrees that PECs and fogging systems are as
effective as fabric filters for controlling PM emissions and thus also
constitute BDT for coal processing and conveying equipment, coal storage
systems, and transfer and loading systems.  In contrast, many other
commenters (084, 085, 088, 089, 093, 094, 095, 099, 107, 112, 115, 116,
117, 119, 120, 123, and 121) stated that proposed opacity standard of no
greater than 5 percent is unreasonably stringent and not supported by
the data set used by EPA used to set the proposed level.  Reasons cited
by individual commenters include:

EPA’s data set includes opacity observations of emissions from coal
preparation at 15 different coal mines from various State environmental
agencies.  EPA acknowledged that because most States regulate such
visible emissions based on the use of Method 22, actual Method 9 tests
are not required on a regular basis.  As a result, EPA recognizes that
“the data we collected were primarily from initial performance
tests.”  That very limited nature of EPA’s opacity data from coal
preparation facilities at coal mines calls into question the propriety
of basing the proposed 5 percent opacity standard on that data.

EPA’s data set only addresses a very narrow segment of different types
of facilities’ operations and emissions characteristics throughout the
industry.

EPA’s data set measured visible emissions cannot be matched with a
specific control technology EPA has determined to be BDT.

EPA’s data set does not demonstrate “achievable emissions” from
“adequately demonstrated technologies” at coal preparation
facilities.

Because the accuracy of Method 9 visual observations is considered to be
±7.5 percent, it is scientifically unsupportable for EPA to select a 5
percent opacity level because most reported the Method 9 performance
test results were 5 percent or less.

EPA has not considered the reasons why 9 percent of the tests in the
data set demonstrated opacity above 5 percent.  Commenter 094 believes
that wind conditions can dramatically affect opacity readings at certain
facilities, and that these conditions are a function of local
meteorological conditions, not of factors that can be reasonably
controlled by the facility operator.  The data set that EPA used does
not appear to have evaluated whether wind conditions at certain sites
made compliance with a 5 percent limit unfeasible, or whether the sites
evaluated consisted of locations with wind speeds that were
representative of industry wide performance for coal-handling
operations.

Several commenters stated an opacity limit such “as less than 10
percent” is more appropriate to reflect demonstrated performance over
the long-term (vs. initial performance tests) and over the range of
operating conditions that may occur considering the highly varied
conditions (e.g., wind, moisture, local geography) that are present at
the various affected facilities throughout the U.S. (093, 099, and 119)

One commenter the opacity limit should be maintained at the existing
standard of less than 20 percent opacity.  Existing facilities are
required to meet the initial 20 percent opacity standard at initial
compliance testing prior to final permit approvals.  Subsequent
maintenance records document that control equipment remain in place and
continue functioning according to the design.  Initial Method 9 testing
and equipment maintenance is required to protect air resources for those
emissions not collected and vented.  There appears to be no demonstrable
reason to reduce the current and highly effective opacity standards and
practices already in place within the coal industry. (121)

Response:  As explained in the response to comment <IP_ADDRESS>.3, EPA has
reevaluated the data used to establish the supplemental proposal’s
opacity limit, as well as assessed information submitted in response to
the supplemental proposal, and has determined that a standard of less
than 10 percent opacity more appropriately represents a level that
reflects the variability associated with long-term operation and
site-specific operating conditions.  Thus, the final rule requires
coal-handling facilities to maintain opacity levels of less than 10
percent.  With respect to the commenter’s statement regarding the
accuracy of Method 9 visual observations being ±7.5 percent, EPA’s
response to comment <IP_ADDRESS> explains that the commenters have
misrepresented the discussion in Method 9 about potential for positive
bias when applying the method.  The study does not support a conclusion
that there is a known positive measurement bias when using Method 9.

Comment:  Two commenters (099 and 119) state that the commenters’
support for fugitive opacity limits of 7 percent (for facilities other
than crushers) and 12 percent (for crushers) in the subpart OOO NSPS
rulemaking was because EPA provided a longer averaging period for
demonstrating compliance (i.e., the average of five 6-minute averages)
which helps to compensate for any bias that might exist in the Method 9
observations.  Commenter 099 urges EPA to adopt such an approach in the
Subpart Y rule.

Response:   As previously explained, EPA has reevaluated the data used
to establish the opacity limit, as well as assessed information
submitted in response to the supplemental proposal, and has determined
that a standard of less than 10 percent opacity for coal-handling
facilities, including crushers, more appropriately represents a level
that reflects the variability associated with long-term operation and
site-specific operating conditions.

<IP_ADDRESS>.4	Alternative to Opacity Limit

Comment:  Two commenters (099 and 119) recommended that EPA not use an
opacity standard in Subpart Y for the affected sources and instead
require a repeat of the proposed Method 22 observation followed by
corrective action.  This approach is discussed in more detail in the
comments submitted by the commenter on the original Subpart Y amendment
proposal which are incorporated by reference by the commenter.

Response:  Subpart Y directs EPA to set “standards of performance”
for the source category except in certain circumstances where it is
infeasible to do so.  A standard of performance is a standard for
emissions of air pollutants which reflects the degree of emission
limitation achievable with adequately demonstrated technologies.  EPA
does not have information to support a determination that the standard
proposed by the commenter would qualify as a standard of performance as
that term is defined in section 111(a)(1).  Further, as a general
matter, EPA believes that rules should be written to include clearly
defined limits that are sufficiently enforceable.  Corrective action
plans or quality improvement plans are not readily enforceable when they
provide no simple line between compliance and noncompliance, and allow
excessive emissions without any deterrence for those emissions beyond a
corrective action requirement.  A clear limit such as an opacity limit
provides an incentive for the source to take corrective action to avoid
the violation prior to, as opposed to after, its occurrence.  Further,
the opacity limit provides a readily identifiable limit to allow for
enforcement where necessary, and results in quantification of the
emissions levels so that the source and the Agency can assure the public
of the environmental performance of regulated facilities.  As such, EPA
is retaining the opacity standards.

3.4.6	PM Emissions Controls and Work Practice Standards

<IP_ADDRESS>	Coal Conveyors

Comment:  Two commenters (114 and 117) stated that that coal conveyors
do not need to be fully enclosed, full enclosures are required only at
the conveyor belt transfer or drop points.

Coal preparation facilities located at coal-fired power plants differ
dramatically from those co-located at mines, and thus what might work at
a power plant may not be appropriate for larger, integrated facilities.
Unlike conveyors at typical coal-fired power plants, conveyors at coal
preparation plants receiving coal from coal mines often move coal for
substantial distances, sometimes for miles, and they have particularly
large capacity.  Under these conditions, it would be unreasonable to
require conveyors to be fully enclosed and vented through a stack (and
hence under pressure).  Not only would such a requirement raise
practicality and safety concerns by increasing the potential for coal
dust and methane gas to accumulate in dangerous concentrations, but it
would create myriad inspection and maintenance difficulties.  For these
reasons only transfer points are typically enclosed (117).

A covered conveyer belt is not going to have any fugitive emissions
along the belt runs.  The only points where fugitive emissions can be
created are at the drop points.  As such, it should be specified that,
for systems that are enclosed, the emission control and monitoring
points for coal conveying equipment should be limited to the material
drop points (114).

Response:  The April 2008 proposal proposed to require conveyers to be
fully enclosed, but the supplemental proposal did not.  The standard of
performance established in the final rule applies to the entire
conveyor.  However, it is common for sources to monitor emissions only
at transfer or drop points on conveyer belts.

<IP_ADDRESS>	Coal Storage Piles

<IP_ADDRESS>.1	Work Practice Standards

Comment:  Several commenters (089, 091 and 121) stated that it is not
feasible to establish emission standards for open storage piles or
roadways, and if open storage piles are to be regulated by Subpart Y
then the only appropriate method for controlling PM emissions from such
sources is by using work practice standards.  A third commenter (126)
does not support establishing an opacity limit for open storage piles or
roadways and concurs with the proposal to establish work practice
standards instead of opacity or PM limits.  If an opacity limit is
established for storage piles, it should be limited to stationary open
storage piles not including piles of coal that have been loaded into
trucks, railcars, and/or ships.  Another commenter (113) disagrees that
only work practices are suitable for controlling PM emissions open
storage piles (and roadways).  The 20 percent opacity limitation under
Subpart Y has been an existing applicable requirement for fugitive dust
sources in the coal-handling system for decades.  It was not proven
infeasible to conduct opacity monitoring over all of those years.  A
more detailed explanation of why opacity monitoring for these fugitive
dust sources cannot be conducted would be very helpful.

Response:  As explained elsewhere in this document, EPA is withdrawing
its proposed requirements for roadways.  EPA concurs that it is not
feasible to prescribe or enforce a standard of performance for open
storage coal piles and has therefore promulgated work practice
standards, which EPA believes provide the most effective method of
limiting emissions from open storage piles.  In addition, EPA believes
that the size of open storage coal piles makes the use of Method 9
opacity observations unreasonable in many situations.

Comment:  One commenter (096) recommended that if EPA declines to
promulgate standards of performance for coal storage piles, the work
practice standard for open piles must be revised to include guidance on
the effective use of wet suppression.

Response:  EPA believes that it is inappropriate to go into the level of
detail suggested by the commenter.  Rather, EPA believes that the
subpart Y requirement is sufficiently detailed as written.

<IP_ADDRESS>.2	Enclosure of Coal Storage Piles

 Comment:  One commenter (096) states it is entirely feasible for
fugitive dust from coal storage piles to be emitted through a conveyance
designed and constructed to emit or capture that fugitive dust.  Coal
storage piles can be enclosed and their fugitive dust emissions vented
to a fabric filter where those emissions can be captured and measured.
The commenter references their comments on the original Subpart Y
amendment proposal for a list of facilities around the country that are
currently utilizing enclosures for coal and coke piles, as well as a
discussion of the economic costs and benefits of enclosing piles.  In
contrast, another commenter (099) stated that power plants typically
have both short-term and long-term storage piles which are vastly
different in size.  Cost and practical considerations in controlling
dust from short- and long-term coal piles will vary considerably.
Long-term piles can be massive, and may range from 40 acres to over 80
acres in size.  The expense of a partial enclosure at such a coal
storage pile would be “enormous” according to the commenter.

Commenter 129 disagrees with Commenter 096 regarding requiring open coal
piles to be enclosed and vented to control emissions.  Commenter 129
states that EPA has ample facts in the record to reject the contention
that all storage piles should be covered and vented to a fabric filter
because long-term piles can become massive and the cost to cover and
control emissions for these massive piles can become quite enormous.
Commenter 129 refers to the cost estimates submitted by a third
commenter (033) concerning the building of a coal silo for short-term
coal storage use and Commenter 129 states that these costs are far
beyond what is considered reasonable cost under CAA section 111.
Commenter 129 also points out that building domes at the port of Los
Angeles Terminal to hold coal before moving it to barges for transport
to Asia also exceeds reasonable costs under CAA section 111.  They also
stated that other examples given by Commenter 096 do not support
enclosing coal piles for long-term storage.

Response:  EPA continues to believe that the cost of requiring open coal
storage piles to be enclosed is unreasonable and thus has not determined
that complete enclosures with fabric filters constitute adequately
demonstrated control technologies for open storage piles at this time.

<IP_ADDRESS>	Coal Preparation Plant Roadways

<IP_ADDRESS>.1	Coal Haul Road Exemption

Comment:  Two commenters (096 and 113) disagree with the proposal to
exclude “roadways that do not leave the property (e.g., haul roads at
coal mines)” from this requirement (74 FR 25313).  The only reason
given for this exclusion is the particular impracticality of, for
example, paving roadways that are frequently rerouted (74 FR 25313).
The proposal offers no explanation for why wetting the road surface
would pose a “particular impracticality” to facility operators, even
given that internal haul roads are frequently rerouted.  Furthermore,
road wetting can be accomplished in a manner that is easy to adjust with
the re-routing of haul roads, including the use of water trucks and
temporary sprayers.  EPA’s rationale also statement is contradicted by
the fugitive dust control requirements already included in the title V
permits for certain coal preparation plant facilities, and by State
regulations that apply to all road types.  The commenter cited examples
of several title V permits and State regulation requiring implementation
of roadway-specific fugitive dust control work practice at coal
preparation plants.  Commenter 113 states that the final rule should
describe the O&M of each open storage pile practice [enclosure, chemical
suppressants (including encrusting agents), wet suppression, a wind
barrier, or a vegetative cover to control emissions], and operation and
maintenance for roadway practices (pave the roads, wet the road surface,
sweep up excess coal dust, or install tire washes to remove entrained
dust to control PM emissions.)

Response:  As discussed in the responses to comments <IP_ADDRESS>.1 and
<IP_ADDRESS> above, EPA’s intent under this action was only to cover
operations on the premises of the coal preparation and processing plant
and, thus, not roadways that lead to the first hopper or from the
loadout operations.  In addition, as previously explained, further
review of the SMCRA regulations and the comments received has led EPA to
withdraw its proposal to regulate roadways on the contiguous coal
preparation and processing site. EPA will continue to assess the need
for regulation of roads beyond the contiguous coal preparation and
processing site.

EPA disagrees that the final rule should describe the O&M of each open
storage pile practice.  One reason for requiring approval of the
fugitive coal dust emissions control plan is to ensure that whatever
control measure is selected by an owner/operator, including its
operation and maintenance, is appropriate considering the site-specific
conditions.

<IP_ADDRESS>.2	Truck Washes

Comment:  One commenter (096) stated that the issue of entrained dust is
not limited to truck tires.  The work practice standards for roadways
“require the owner/operator to pave the roads, wet the road surface,
sweep up excess coal dust, or install tire washes to remove entrained
dust to control PM emissions” (74 FR 25313).  Subpart Y must be
amended to require the installation of “truck washes” as opposed to
merely “tire washes.”  Truck washes clean the entire truck body,
including the undercarriage and other areas where mud and dust may
collect.  Limiting the standard to only tire washes would not adequately
address the dust entrainment problem.

Response:  As noted elsewhere, EPA is withdrawing its proposed
requirements for roadways to be included in the Subpart Y fugitive coal
dust emissions control plan as it believes that these sources are
adequately covered under the requirements of SMCRA.   EPA believes that
such emissions as the commenter notes would also be covered under the
required SMCRA fugitive dust plan.

<IP_ADDRESS>.3	Weather-Related Exemptions

Comment:  One commenter (114) suggested that the rule should acknowledge
that the listed control methods for haul roads may not be available when
temperatures are below freezing.  In addition, prevailing weather
conditions may reduce the effectiveness of, or eliminate the need for, a
particular control method on a given day.

Response:  As noted elsewhere, EPA is withdrawing its proposed
requirements for roadways.  However, with respect to open storage piles,
section 60.254 of Subpart Y specifies that the fugitive coal dust
emissions control plan must describe the control measures the
owner/operator will use to minimize fugitive emissions from each source
addressed in the plan, and explain how the measures are applicable and
appropriate for the site conditions.  Weather-related issues such as
those noted by the commenter thus can be addressed in the fugitive coal
dust emissions control plan.

<IP_ADDRESS>	Coal Truck Dumps

Comment:  Two commenters (117 and 124) support the use of stilling sheds
as BDT for truck dumps.  Truck dumps using stilling shed technology
control fugitive coal dust more effectively than those using baghouses.
The WDEQ considers stilling sheds effective enough to constitute BACT.
Therefore, if EPA decides to establish truck dump standards, despite the
foregoing concerns, the commenter requests that EPA make a finding that
stilling sheds constitute BDT for truck dumps.  Another commenter (122)
stated that many coal mines utilize stilling sheds; however, there are
some truck dump control systems that utilize baghouses or water spray
bars and their data is presented here as well.  Regardless of the
method, these truck dump control systems are rated to control 50-85
percent of the fugitive emissions from truck dumping.  It should be
noted that some mines operate belly dump trucks, for which no safe
stilling shed design is available.

Commenter 126 stated that the truck dumps are proposed to be regulated
as a point source and the commenter does not consider it appropriate to
regulate a truck dump in the same manner as a baghouse or PEC.  The PSD
rules define fugitive emissions as those which could not reasonably pass
through a stack, chimney, vent, or other functionally equivalent
opening.  With haul truck capacities of 400 tons, it is not reasonable
to assume that the emissions could be routed through a stack.  Commenter
suggests that truck dumps be regulated as fugitive sources.

Response:  EPA continues to believe it is appropriate to require coal
truck dump operations, whether unloading coal into a hopper, onto an
open storage pile, or elsewhere, to be subject to the same opacity limit
as other coal-handling facilities.  As previously explained, an
owner/operator may use any control measure that enables them to meet the
opacity limit.  Data indicate that the various control measures
currently used on truck dump operations (e.g., baghouses, water sprays,
stilling sheds) are capable of meeting the final rule’s opacity limit
of less than 10 percent.  However, as explained in the response to
comment <IP_ADDRESS>, EPA has determined that separate testing and monitoring
requirements are appropriate for coal truck dumps.

<IP_ADDRESS>	Affected Facilities in Enclosed Buildings

Comment:  Many commenters (085, 088, 095, 107, 112, 115, and 120)
requested that Subpart Y provide the same compliance alternative for
affected sources located in enclosed building stated provided in subpart
OOO.  Under subpart OOO performance standards and applicable monitoring
techniques for the exhaust systems of these buildings have been
specified as an appropriate alternative to individual compliance by each
affected facility enclosed within the building.  Building enclosure of
certain coal-handling and processing operations at coal preparation
plants has become more commonplace throughout the industry for several
reasons, including the ability to effectively control emissions and to
protect personnel and equipment from the elements. These commenters urge
EPA to extend this practical and achievable alternative to Subpart Y and
recognize within the rule the beneficial control technique of enclosing
coal preparation facilities within buildings.

Response:  EPA has determined that if a building in which affected coal
processing and conveying equipment (e.g., breakers, crushers, screens,
conveying systems), coal storage systems, and coal transfer system
operations are enclosed is found to be in compliance with Subpart Y
limits then the affected facilities enclosed in that building also are
in compliance.  Because exhaust from a building that encloses affected
facilities would be comprised of exhaust from the affected facilities,
it follows that in order for the building to be able to meet a specific
opacity limit, each facility enclosed in the building also would have to
meet that same opacity limit.  That is, for coal processing and
conveying equipment, coal storage systems, and transfer and loading
systems constructed, reconstructed, or modified on or before April 28,
2008, fugitive emissions from the building openings must not exhibit 20
percent opacity or greater. Fugitive emissions from buildings that
enclose coal processing and conveying equipment, coal storage systems,
and transfer and loading systems constructed, reconstructed, or modified
after April 28, 2008, must not exhibit opacity of 10 percent or more.
For buildings enclosing coal processing and conveying equipment, coal
storage systems, and transfer and loading systems constructed,
reconstructed, or modified after April 28, 2008, that discharge
emissions from a mechanical vent, emissions must not contain PM in
excess of 0.023 g/dscm (0.010 gr/dscf).

<IP_ADDRESS>	Site-Specific Fugitive Emission Control Plan

<IP_ADDRESS>.1	Need for Plan in Subpart Y

Comment:  One commenter (103) requested that EPA delete the proposed
fugitive emission control plan requirements from the final Subpart Y
amendments for the following reasons:

Regulated entities have the right to know exactly what requirements
apply to their facilities, particularly those applicable to new sources,
and the proposed language does not provide any objective basis for
determining what might have to be included or how to comply.

Making fugitive emission control plan requirements these subject to
negotiation and air regulatory agency approval adds potentially
significant delays in getting new sources approved and into operation.

Fugitive emission control plans to minimize emissions from coal piles
and roadways are commonly embodied in state implementation plans and
existing air permits for iron and steel plants and coke plants.

Subpart Y should not duplicate and should not conflict with existing
fugitive emission control requirements that have been in place for many
years in the title V operating permits for individual plants.  Affected
sources should be exempt from NSPS fugitive emission control
requirements if covered by an applicable fugitive emission control plan
referenced in a Title V permit.

Response:  EPA disagrees that fugitive coal dust emission control plans
should not be required by the NSPS.  The commenter states that such
plans are “commonly” embodied in State implementation plans but does
not suggest that they are contained within all such plans.  Adding to
the NSPS a requirement that sources must control fugitive coal dust
emissions from fugitive sources at the facility by operating according
to a written fugitive coal dust emissions control establishes a uniform
requirement that applies to all sources in the Subpart Y source
category.  The final rule also provides very specific requirements
regarding the control measures that must be included in the fugitive
coal dust emissions control plans.  The fugitive coal dust emissions
control plan must identify and describe the control measures the
owner/operator will use to minimize fugitive coal dust emissions from
each affected facility addressed in the plan.  The owner or operator is
also required to explain how the measures are applicable and appropriate
for the site conditions.

The owner/operator may petition the Administrator requesting approval of
a control measure other than those specified in the final rule.  The
petition must either demonstrate that the alternate control measure will
provide equivalent overall environmental protection or demonstrate that
it is either economically or technically infeasible for the affected
facility to use the control measures specifically identified in the
final rule.  The final rule clarifies that the owner/operator must
submit a fugitive coal dust emissions control plan that includes the
alternative measures along with the petition and operate in accordance
with that plan while the petition is pending.  It further clarifies that
while operating in accordance with the plan that includes the
alternative control measures, the affected facility is considered to be
in compliance with the fugitive coal dust emissions control plan
requirements while the petition is pending.

<IP_ADDRESS>.2	Plan Requirements

Comment:  Many commenters (085, 087, 088, 095, 099, 107, 112, 114, 115,
117, 119, 120, and 121) stated that EPA’s proposal for
owners/operators to develop a fugitive dust emissions control plan for
open storage piles, roadways, and other site-specific sources of
fugitive emissions is not clear with respect to the affected sources and
information owners and operators are required to include in their
written fugitive emissions control plans.

EPA has failed to properly develop revisions to Subpart Y in accordance
with established procedures for developing NSPS that specifically
designate each type of affected facility subject to proposed standards.
EPA needs to clarify what exactly what affected sources are intended to
be addressed by the plan.  The requirement for a plan seems to be an
attempt by EPA to apply standards to any and all facilities and
activities at a coal preparation plant. Additionally, this appears to be
an open-ended and indeterminate expansion of Subpart Y. This intent is
further reflected in preamble language indicating that proposed
procedures for developing a “fugitive dust plan” must include
procedures for limiting emissions from “all types” of coal
processing and conveying equipment at coal preparation plants (74 FR
25312). It is unclear what EPA means by “all types” of equipment
when “coal processing and conveying equipment” has a well-settled
meaning within Subpart Y.

EPA appears to be using inappropriate terminology, at times referring to
a “fugitive dust emissions control plan” and alternatively referring
to a “fugitive dust plan.”  Fugitive process emissions are not the
same as fugitive dust, or non-process emissions.

EPA intent is unclear of what information owners and operators are
required to include in their written fugitive emissions control plans.

Proposed rule amendment does not, but should, make clear that an owner
or operator can choose from the methods stated in the rule or an
alternative method, if one exists, approved by the permitting authority.
 As currently proposed, any alternative methods would have to be
approved by the Administrator.  Such a requirement would be unduly
burdensome.

60.254(b)(3) discusses the need for a fugitive emissions control plan
for fugitive sources “at the facility.”  The use of the term
“facility” is inconsistent with its meaning throughout the remainder
of the rule and the historical use of the term in this subpart.
Applicability is determined on a unit-by-unit basis.  Haul roads have
not been identified as an “affected facility” per the existing
definition under the NSPS.  Consequently, EPA needs to rewrite this
section in order to remove the confusion generated by the ambiguous
wording.

60.254(b)(3)(ii) requires the fugitive emissions control plan to specify
one or more of several listed control methods for open storage piles and
haul roads.  The regulation should acknowledge that these measures might
not be available when temperatures are below freezing and that
prevailing weather conditions may reduce the effectiveness of, or
eliminate the need for, a particular control method on a given day.

It is confusing and unclear as to what roads to be included in plan.  Is
it all roads associated with the facility, , or is it roads associated
only with the footprint of the coal-handling facility and used in the
coal-handling itself.  All facility roadways are handled in accordance
with SMCRA requirements and permits and it would appear that there is no
need to duplicate existing regulatory requirements with another layer of
oversight.  Further, ramps and roadways directly associated with a
coal-handling facility often are not defined as “roads” per se;
rather, like the structures and buildings, they are simply part of the
“facility.”

Response:  EPA has decided to omit, from the rule, the proposed
requirement that the fugitive coal dust emissions control plan address
“other site-specific sources of fugitive emissions that the
Administrator or permitting authority determines need to be included.”
 EPA agrees with the commenters that Subpart Y should specifically
identify each type of affected facility that must be addressed in the
fugitive coal dust emissions control plan.  As explained earlier in this
preamble, EPA also has decided not to address roadways under Subpart Y
at this time.  Thus, open storage coal piles are currently the only
affected facilities that must be addressed by the plan.  As pointed out
by the commenters, an owner/operator must either use one of the control
measures specifically identified in subpart Y or, alternatively, seek
approval from the Administrator to use an alternate control measure.
Because the NSPS is a Federal standard, we believe it is appropriate for
the Administrator to be the one who makes determinations regarding
whether an alternative control measure achieves equivalent overall
environmental protection.  Weather-related issues such as those noted by
the commenter should be addressed in the fugitive coal dust emissions
control plan prepared by the owner/operator.

.

 The regulatory text in Subpart Y has been revised such that use of the
terms “facility ”and “fugitive dust emissions control plan” are
consistent throughout the rule.

<IP_ADDRESS>.3	Plan Implementation

Comment:  One commenter (117) stated that the proposed requirements that
the permitting authority approve the site-specific fugitive dust plan
would be unnecessary. The better and less burdensome approach is to
require owners/operators to submit their fugitive dust controls plans to
the permitting authority, and those plans would automatically take
effect unless the permitting authority objects to the terms of the plan.
 Another commenter (096) stated that the proposed requirements do not
specify which permitting authority will be required to approve fugitive
dust emissions plans under the proposed regulation.  It is entirely
unclear, for instance, whether fugitive dust emissions plans will be
required to be incorporated into a coal preparation plant’s title V
permit.  EPA must clarify these requirements for the preparation and
approval of the fugitive dust emissions control plans.  At a minimum,
the commenter stated that EPA must require that these fugitive dust
emission control plans be subject to public notice and comment, whether
or not they are incorporated into a plant’s title V permit.

Response:  The requirement to control fugitive coal dust emissions by
operating according to a written fugitive dust emissions control plan is
a Federal requirement and is Federally enforceable.  The final rule does
not require approval of the plans by the Administrator or delegated
authority.  In addition, the commenter does not identify any provision
of CAA section 111 that would require the NSPS itself to establish a
notice and comment process for the plans.  However, this rule does
require the owner/operator to submit the fugitive coal dust emissions
control plan to the Administrator or delegated authority to provide an
opportunity for the Administrator or delegated authority to object to
the fugitive coal dust emissions control plan.  The final rule requires
the owner/operator to submit the fugitive coal dust emissions control
plan to the Administrator or delegated authority before startup of the
new, reconstructed of modified facility.  If an objection is raised, the
owner/operator has 30 days from receipt of the objection to respond with
a revised fugitive coal dust emissions control plan.  The owner/operator
must operate in accordance with the revised fugitive coal dust emissions
control plan.

The requirement for the owner/operator to prepare and operate according
to a submitted fugitive coal dust emissions control plan that is
appropriate for site conditions must be included in the title V
operating permit for the source.  This and other requirements for title
V permits are addressed in 40 CFR part 70.

Finally, to the extent the comment raises issues beyond the scope of the
supplemental proposal, EPA has no obligation to respond in this
rulemaking.

<IP_ADDRESS>.4	Plan Submittal Date

Comment:  Three commenters (087, 099, and 119) stated that EPA’s
proposal requires submittal of the fugitive emissions control plan to
the permitting authority 90 days prior to the compliance date.
Commenters assume this means the date for conducting the performance
test under section 60.8, which is 60 days after reaching maximum
production but not more than 180 days.  If EPA finalizes its proposed
approach and subjects existing units to fugitive emissions control
plans, commenters request guidance on how the 90-day requirement is
applied with respect to the effective date of the final rule and the
proposed April 2008 applicability date.  A modified open coal storage
pile that is required to submit a fugitive dust plan may be required to
comply before the rule is effective and therefore could not meet the
90-day requirement.  The 90-day requirement also is difficult to meet
with the provision giving the permitting authority discretion to decide
what site-specific sources must be covered by the plan.  An affected
owner/operator would not know what to put in the plan.

Response:  The commenter’s statement that some open storage coal piles
are required to comply before the rule is effective is not completely
accurate.  With respect to open storage piles, May 27, 2009, is the date
used to determine which sources qualify as “new sources” as that
term is defined in CAA section 111(a)(2).  The rule requirements for
open storage piles apply to any stationary open storage pile sources,
the construction or modification of which is commenced after that date.
The compliance obligation doesn’t arise until the effective date of
the revised NSPS rule.  However, because CAA section 111(b)(1)(B)
provides that standards of performance or revisions thereof shall become
effective upon promulgation, all sources that qualify as “new
sources” must be constructed in accordance with the regulations.
Further because both the requirement that new sources include sources
constructed or modified after the date of the proposed regulations and
the requirement that the standards become effective upon promulgation
are statutory requirements, EPA does not have authority to alter these
requirements.  The specific situation raised by the commenters is no
longer relevant because the final rule does not require approval of the
fugitive coal dust emissions control plan.

3.4.7	Reconstructed and Modified Sources

<IP_ADDRESS>	Coal Storage Piles

Comment:  Many commenters (087, 094, 099, 103, 105, 109, 114, 117, and
119) stated concerns about the inherent difficulties in determining when
an open storage pile is “reconstructed” or “modified.”  There is
simply no way that an “increase in the emission rate” of PM or any
other pollutant could be measured with any certainty for an open coal
storage pile (or roadway).  Unlike other “affected facilities” or
plant equipment, open storage piles by their nature fluctuate in size
and activity.  As the Subpart Y amendments are proposed, any time large
coal inventory was added to an open storage pile and then reclaimed,
Subpart Y potentially could be triggered.  If EPA proceeds with the
establishment of work practices for coal piles, EPA should provide
clarification and guidance as to what constitutes a physical or
operational change for an open storage pile or roadway through a
subsequent rulemaking proposal that would allow public review and
comment.  Commenters requested that EPA limit the applicability of the
Subpart Y control requirements for coal storage piles to only new
sources.

Response:  EPA agrees with the commenters that open storage piles are
always changing (i.e., coal is being added and coal is being removed for
processing) and, for purposes of subpart Y, we do not consider the
routine addition and removal of coal to be a physical change or a change
in the method of operation.  A change to an open storage pile that
requires the source’s operating permit be opened for revision may be a
modification or reconstruction of the storage pile.  Instances where a
physical change or change in the method of operation of an open storage
pile will result in an increase in emissions would be considered a
modification or reconstruction (e.g., increasing the permitted size of
the storage pile).  Changes to the equipment used in loading, unloading,
and conveying operations of open storage piles are among the things that
can be assessed in order to determine when an open storage pile has been
reconstructed or modified.  Thus, in the final rule, EPA defines “open
storage pile” to mean “any facility, including storage area, that is
not enclosed that is used to store coal, including the equipment used in
the loading, unloading, and conveying operations of the facility.”
The inclusion of a definition for “open storage pile” should provide
additional clarification as requested by the commenters.  In addition,
40 CFR 60.5 provides that when requested to do so by an owner/operator,
the Administrator will make a determination of whether action taken or
intended to be taken by such owner/operator constitutes construction
(including reconstruction) or modification or the commencement thereof
within the meaning of this part.

<IP_ADDRESS>	Coal Preparation Plant Roadways

Comment:  Many commenters (087, 094, 099, 103, 109, 114, 117, and 119)
stated that there are  inherent difficulties in determining when a plant
roadway is “reconstructed” or “modified” and therefore requested
that EPA limit the applicability of the Subpart Y control requirements
for plant roadways only to new sources.  Activities on power plant
roadways (onsite haul roads) can include realignment, scraping, grading
and paving.  Furthermore, the dynamic nature of these types of
activities makes it very difficult to determine what would constitute a
modification or reconstruction of a haul road.  If EPA proceeds with the
establishment of work practices for plant roadways, EPA should provide
clarification and guidance as to what constitutes a physical or
operational change for a roadway through a subsequent rulemaking
proposal that would allow public review and comment.

Response:  As noted elsewhere, EPA is withdrawing its proposal to
regulate roadways under Subpart Y, believing that the requirements of
SMCRA are sufficient.  However, EPA will continue to assess the issue.

3.5	Subpart Y Testing and Monitoring Requirements

3.5.1	PM Emissions Testing

<IP_ADDRESS>	PM Performance Test Frequency

Comment:  Several commenters (087, 099, 119, and 117) stated that the
proposed requirements for subsequent PM emissions performance test after
the initial compliance test are either not needed or require too
frequent testing resulting in unnecessary testing.

For most units, repeat PM performance testing should be required no more
often than every five years.

One commenter stated that once a source has established based on an
initial performance test that a PM control device is properly sized and
installed to meet the applicable PM limit, stack testing is not
necessary to ensure continued compliance.  Compliance can be determined
through visible observations using procedures like Method 22 or other
operating parameters, like BLDS.  The recent revisions to subpart OOO,
EPA agreed and required no repeat PM performance testing for facilities
performing ongoing monitoring under section 60.674 (e.g., those
facilities using BLDS, monitoring scrubber parameters, or performing
quarterly Method 22 observations).

One commenter (117) noted that if EPA ultimately adopts the BLDS
requirement; it should recognize that facilities that use such devices
are likely to operate in compliance with EPA’s proposed standards
because deviations would be detected before any noncompliance occurs.
These facilities should, therefore, be exempt from ongoing opacity
monitoring requirements, other than the initial and five-year
performance tests.  This would be consistent with the approach EPA
adopted for the electric arc furnace NSPS under 40 CFR 60 subparts AA
and AAa.

Response:  The emissions testing requirements for PM, SO2, NOX, and CO
accomplish two goals.  First, emissions measurements are necessary to
directly determine compliance with the applicable emissions limit.
Direct measurement will also provide data necessary to verify the
accuracy of the annual compliance certifications.  The data will also
augment the data supporting the regional and national emissions factors
and emissions inventories.  Second, periodic performance testing will
verify the calibration and representativeness of the continuous
monitoring system (e.g., BLDS, scrubber pressure drop) and, as
necessary, indicate that readjustment is required.  EPA does not believe
that these goals can be met with emissions testing for each separate
source on a 5-year cycle.  EPA has, however, provided a provision that,
for affected facilities that emit at 50 percent or less of the
applicable standard, repeat performance testing is required every 24
months (as opposed to every 12 months).  Also, for well-performing
(emitting at 90 percent or less of the applicable standard) similar,
separate sources using identical control equipment, the final rule
allows a single repeat performance test as adequate demonstration for up
to four other similar, separate sources. Under this provision, a
performance test for each of these similar affected sources is required
to be conducted at at least once every 5 years (i.e., one similar source
would be required to conduct repeat performance testing every 12
months).

<IP_ADDRESS>	Small Fabric Filters PM Performance Test Exemption

Comment:  Several commenters (087, 099, 119, and 117) stated that
implementation of the proposed provision exempting small fabric filters
from PM performance tests may be hindered by the same difficulties
regarding calculation of the “design controlled potential PM emissions
rate,” and conditioning the exemption on use of COMS or qualification
for use of the Method 22 alternative is either unnecessary or
unreasonable.  In light of these problems, EPA should reconsider its
approach and, consistent with subpart OOO, utilize ongoing monitoring
and corrective action requirements, rather than repeat performance
testing, to assure compliance. EPA and states would retain authority
under section 60.8 to require performance testing at individual
facilities on a case-by-case basis in response to audits of the facility
or its monitoring reports.

Response:  As explained in response to one of the comments in <IP_ADDRESS>
below, the final rule does not contain any provisions that require the
alternative monitoring the commenter refers to (i.e., digital opacity
monitoring system or COMS).  The final rule does continue to base one of
its provisions regarding the frequency of subsequent emissions
performance testing on “design controlled potential PM emissions
rate” (Mg/year).  The final rule includes a definition of the term
“design controlled potential PM emissions rate

<IP_ADDRESS>	Performance Test Delay for Non-operating Affected Sources

Comment:  Several commenters (087, 099, and 119) suggested a revision to
the proposed provision authorizing a delay in PM performance testing for
any facility that “has not operated for the 60 calendar days prior to
the due date of a performance test.”  Although the commenters support
the proposed relief, they suggest that EPA instead allow a grace period
for any unit that “is shutdown and not operating” on the due date.
This more flexible language would prevent the need for submission of a
waiver request for a unit that is unexpectedly shut down prior to
testing and would avoid the inequity of denying relief to a unit that
might operate only briefly in the 60 days before the due date, but not a
sufficient time to complete testing.

Response: EPA believes it is inappropriate to allow a delay in PM
performance testing for “any unit that is shutdown and not operating
on the due date of the performance test.”  Because there can be
various reasons for a unit to be shutdown and not operating at the time
a performance test is required, EPA considers it imprudent to provide a
general waiver allowing a delay in testing for these units.  In order to
consider the merits of each situation, EPA believes it is appropriate to
require case-by-case waiver requests for situations where an affected
facility is shutdown and not operating on the due date of the
performance test, with the exception of affected facilities that have
not operated for the 60 calendar days prior to the performance test due
date.

<IP_ADDRESS>	Use of Method 17 as Alternative PM Test Method

Comment:  Several commenters (087, 099, and 119) support EPA’s
proposal allow use of Method 17 of Appendix A-6 to determine PM
concentration for the purpose of complying with subpart Y.

Response:  EPA appreciates the commenters’ support of its approach.

<IP_ADDRESS>	Performance Testing of Multiple Similar Affected Facilities

Comment:  One commenter (113) disagrees with the proposal to allow a
performance test at one facility to count for an adequate demonstration
of performance at “up to four other similar, separate affected
facilities.”  This is flawed because different facilities will be
operated differently in different jurisdictions.  Each facility may have
conditions unique to that facility that could result in performance
variations.  Also, an operator may operate facilities in different
States to a different degree of compliance with CAA title V permit terms
and conditions because some States are less effective at enforcing
permits than are other States.

Response:  The commenter has misinterpreted section 60.255(d) of the
supplemental proposal. The term “affected facilities” refers to
affected “sources” at the same plant (e.g., five conveyor transfer
points that are identically controlled and vented).  The provision does
not apply to affected sources across plant sites, even if those sources
are identical.  Section 60.255(d) includes additional conditions that
must be met in order to take advantage of the provision (e.g., regarding
the level of PM emissions, recommended control device maintenance
procedures, type of monitoring, PM testing frequency).

Comment:  One commenter (108) states that the EPA proposes an
alternative for showing opacity monitoring compliance.  This alternative
plan proposes that one test per four similar systems.  The proposal
appears to state that the operator could conduct a Method 22 observation
for up to 4 similar affected facilities, and agree to an
inspection/maintenance program for the equipment.  But observations
would be required weekly for each source, and the facilities must still
conduct a monthly formal observation for each piece of equipment.  So
the commenter is confused as to how this is any less than the initial
proposal.  Also, the proposed rule, at 60.255(d) appears to discuss five
facilities (not four), so this is also confusing.  This one for four
proposals is getting closer to being acceptable, but is still excessive.
 The commenter suggests an alternative where the EPA should use the
inspection program the EPA recently approved for subpart OOO facilities
and which is similar to the program proposed in the proposed Subpart Y
at section 60.258 of 74 FR 25326.

Response:  The “one test per four similar systems” provision
included in the supplemental proposal regards emissions testing (i.e.,
PM, SO2, NOX, CO), not opacity testing.  Additionally, this provision
allows a single performance test for up to four “other” similar,
separate affected facilities, for a total of five simultaneous
performance tests.  The supplemental proposal also included a provision
that allows simultaneous visible emission observations using Method 9
for up to three emission points.  The final rule retains both of these
provisions.  However, the final rule includes revised opacity testing
and monitoring requirements which are described in the responses to
comments below.

Comment:  Two commenters (099 and 119) stated that although the
commenter agrees with EPA’s proposal to reduce the number of initial
performance tests required for identical facilities, there are concerns
how some of the proposed criteria can be implemented.  Their concerns
include:

How a facility would calculate the “design controlled potential PM
emission rate” of a control device in terms of Mg per year.  Although
the design efficiency of the control device and design flow rate may be
known, the resulting theoretical annual emissions cannot be calculated
without knowing the annual uncontrolled emissions (or how much dust will
be vented to the control device in a year).

The term “design emissions limit” of the “affected facility” in
proposed section 60.255(d)(1) is not defined and must be different from
the “design controlled potential PM emissions rate” of the control
device, which is defined in terms of Mg per year and not in the terms of
the applicable PM limit (gr/dscf).  The commenter requests clarification
regarding this term.  The commenter also does not understand how an
owner/operator would establish that the performance test results for
“each individual affected facility” is 90 percent or less of the
standard, if each individual affected facility or control device is not
being tested.

Commenters 099 and 109 do not understand why EPA would condition the
provision on compliance with use of the alternative opacity monitoring
in proposed section 60.255(e) or (f), given that the facilities already
would be subject to periodic opacity performance testing under proposed
section 60.255(b)(2), and could use the alternatives under subsections
(e) and (f), if applicable.  Imposition of this condition has the effect
of unnecessarily limiting the facilities’ options for monitoring of
opacity.  If by imposing the alternative opacity monitoring EPA intends
to require the facilities to either maintain opacity less than 3 percent
based on Method 9 to qualify for use of the Method 22 alternative, or to
install COMS, the commenter objects.  The commenter does not believe
that Method 9 has been adequately demonstrated for determining opacity
at 5 percent, let alone “less than 3 percent,” and installing COMS
on each stack would impose expense that is inconsistent with EPA’s
goals of reducing the cost of determining compliance at identical
facilities.

Response:  The supplemental proposal required initial emissions
performance testing for all affected facilities.  The provision that
allows, under certain conditions, simultaneous emissions testing of five
similar, separate affected facilities using identical control equipment
regards subsequent performance testing.  As previously noted, the final
rule includes this provision.

The final rule does not contain any provisions that require “design
emissions limit” to be determined or that require the alternative
monitoring the commenter refers to (i.e., digital opacity monitoring
system or COMS).  The final rule does continue to base one of its
provisions regarding the frequency of subsequent emissions performance
testing on “design controlled potential PM emissions rate”
(Mg/year).  The final rule includes a definition of the term “design
controlled potential PM emissions rate.

3.5.2	Visible Emissions Testing

<IP_ADDRESS>	Need for Method 9 Performance Tests

Comment:  One commenter (114) stated that for affected facilities
subject to both an opacity limit and a PM limit, requiring testing for
both limits.  This is excessive in both cost and effort, especially
considering the total contribution of these sources to the emissions at
a given operation.  Testing for both PM and opacity should not be
required.