increasing both the chance that a single compliance measurement would
be out of compliance, as well as the overall emissions loading used to
evaluate the environmental performance of the unit. The commenter
submitted that such operating limits applied to resin strippers are
inappropriate and that where conditions exist that operating limits are
appropriate, proper measurement protocol would be to require sampling
within the normal operating ranges, not at a particular point within.
    Response: In the final rule, for stripped resins as well as for
process wastewater, we are no longer requiring sources to comply with
operating limits and conduct continuous parametric monitoring. The
requirements to conduct resin sampling are sufficient to assure
compliance with the stripped resin limits.
    In our review of the resin sampling data in conjunction with the
establishment of additional subcategories for stripped resins (see
discussion above), we recognize that while resin subcategories are
established at the type of resin, there are a multitude of resin grades
produced by facilities that fall under a general resin type. Some
facilities may produce on the order of hundreds of different grades for
any one particular resin type. For the same reasons outlined as to why
we are establishing additional subcategories for stripped resins in the
final rule, we recognize that there are also differences in the
formulations, recipes and processing conditions in the polymerization
reactors and/or resin stripper for different resin grades of the same
resin type. The establishment of resin subcategories at the grade level
would be impractical because an inordinate number of subcategories
would have to be established for hundreds, if not thousands, of
different grades of resin. As such, the MACT limits established at the
level of resin type will account for the inherent variability in not
only the formulation and recipes of the different resin grades, but
also the variation that must exist in the polymerization and stripping
of different resin grades in order to meet established resin
specifications and end-user requirements. The final rule requires that
compliance with the stripped resin limits be demonstrated based on a
24-hour arithmetic average of samples taken every 3 hours for
continuous strippers or at the end of each batch for batch strippers.
The frequency of resin sampling that is required under the final rule
is sufficient to ensure that continuous and batch stripping operations
are in continuous compliance with the stripped resin limits.
    Therefore, requiring facilities to establish parameters on their
stripping operations that must be monitored and maintained to ensure
continuous compliance is not practical considering the multitude of
operating limits and ranges that would need to be established to cover
the production of numerous grades of resin. We further recognize that
given the establishment of resin limits at the outlet of the resin
strippers, we can allow flexibility in the operation of the strippers
while ensuring that the resin limits are being met as the resin exits
the stripper. Therefore, we have removed all requirements for
continuous parametric monitoring of resin strippers from the final
rule.
    Comment: One commenter contended that a work practice standard is
needed for startup periods for the resin slurry strippers. The
commenter does not normally take samples for vinyl chloride within 2
hours of a PVC resin slurry stripper startup, but provided a table of
information in their comment letter on four investigations undertaken
on different days at different plants. The commenter stated that the
first three products tested were relatively easy-to-strip grades, while
the fourth product was a relatively hard-to-strip pipe-grade resin. The
commenter stated that a relatively short startup vinyl chloride spike
is present for easy-to-strip resins, but that for the higher volume
pipe grade resin with lower porosity (hard-to-strip), the startup spike
lasted at least 1 hour and, possibly, 2 hours. The commenter contended
that, based on the variability seen in the slurry stripper startups, it
is not possible to set a single numerical limit for startup conditions.
Therefore, the commenter requested that the EPA establish a work
practice allowing a 2-hour time period following startup when no vinyl
chloride samples shall be used for compliance purposes.
    Response: The resin limits apply at all times including during
periods of normal operation and during periods or startup and shutdown.
The variability incorporated into the stripped resin limit calculation
for each resin type will sufficiently allow for periods of
concentration spiking during periods of startup. Compliance with the
stripped resin limits is based on a 24-hour arithmetic average of
samples taken every 8 hours for continuous strippers or at the end of
each batch for batch strippers. For a continuous stripper, samples must
be taken every 8 hours or for each grade, whichever is more frequent.
We believe the 24-hour averaging time and 8-hour sampling frequency
will allow sources to demonstrate compliance with the stripped resin
limits. Finally, section 112(h) of the CAA authorizes the EPA to set
work practice standards in lieu of numerical emission limits only where
it is not feasible to prescribe or enforce a numerical emission
standard. This statutory threshold is further defined to

mean that HAP cannot be emitted ``through a conveyance designed and
constructed to emit or capture such pollutant'' or ``the application of
measurement methodology to a particular class of sources is not
practicable due to technological and economic limitations.'' The
commenter did not provide any information to satisfy this statutory
prerequisite to support the application of work practice standards to
startup periods for resin strippers. Therefore, we disagree that a work
practice should be established in lieu of a numerical emission limit
for resin strippers during periods of startup.
4. Wastewater
    Comment: Several commenters contended that owner/operators should
be exempt from the proposed initial and continuous vinyl chloride and
HAP sampling requirements if they can document, through process
knowledge or historical sampling data, that no HAP are present in the
wastewater stream. The commenters proposed that all documentation would
be available to an inspector. Commenters contended that the HON at 40
CFR 63.144(b) and (c) (subpart G) allows for the use of sampling, bench
scale data and/or process knowledge to determine concentration and flow
rate of a wastewater stream.
    Response: In the final rule, we are requiring that for any process
wastewater streams that are not being treated prior to being discharged
from the PVCPU, facilities must sample those streams and determine if
treatment is required to meet the process wastewater limits for vinyl
chloride and total non-vinyl chloride organic HAP. If, after the
initial sampling, treatment is not required to meet the limits, then
those streams must only be retested annually or when a process change
is made. The final rule contains limits based on the MACT floor for
total non-vinyl chloride organic HAP. The total HAP concentration and
flow rate cutoffs were included as a beyond-the-floor option at
proposal in an effort to make the wastewater requirements consistent
with other chemical sector rules, because the option was cost-
effective. Based on our evaluation of the total non-vinyl chloride
organic HAP limits, we determined that the 1,000 ppmw threshold for
total organic HAP, above which facilities would have been required to
comply with the HON wastewater provisions, was not appropriate for the
final rule as all streams must meet a limit for vinyl chloride and
total non-vinyl chloride organic HAP, that, when combined (i.e., 116.8
ppmw for existing sources and 0.30 ppmw for new sources), is much lower
than the previously proposed 1,000 ppmw threshold. We, therefore,
removed the total HAP flow rate cutoff and concentration cutoff, and
flow rate determination requirements from the final rule. Annual re-
sampling and testing of untreated streams is not overly burdensome and
provides more reliable results than engineering estimates or process
knowledge on which to determine whether at some point in the future, an
untreated stream must be treated to meet applicable limits.
    Comment: Some commenters stated that the EPA should provide
exemptions for certain safety-related streams. The commenters contended
that certain events may occur at a PVCPU that require the release and
subsequent discharge of water, such as a fire or the use of eye wash
stations and safety shower, and these activities have little to no
chance of emitting HAP. The commenters stated that safety-related
streams are identified in HON at 40 CFR 63.100(f)(1) through (11). In
the absence of such exemptions, the commenters concluded that facility
employees will be confused or hesitant because of a compliance dilemma
at the worst possible time.
    Several commenters asked for clarification about which in-process
wastewater streams require control and treatment. Several commenters
contended that maintenance wastewater streams should be regulated
independently of process wastewater. The commenters stated that the
capture of maintenance wastewater emissions is infeasible and thus
warrants use of a work practice standard. The commenters stated that
there are no known practical and effective methods for collecting and
controlling fugitive emissions from a wastewater stream, which can vary
considerably in HAP concentration and flow rate. Several commenters
argued that maintenance wastewater should not have a prescribed limit,
but should have work practices to remove residuals prior to generation.
A commenter stated that maintenance activities are non-routine, highly
variable activities that require the purging, clearing and cleaning of
equipment in preparation for safe handling by personnel. Some
commenters added that maintenance wastewaters include dilute
concentrations of HAP because industry takes efforts to remove residual
HAP before equipment is flushed. The commenters concluded that
quantifying a concentration to establish compliance with a limit would
be extremely difficult if not impossible, because the ``acceptable''
level would be based on the specific circumstances involved. The
commenters added that other MACT standards like the HON and MON provide
a separate management option for maintenance or turnaround wastewater.
    The commenters contended that streams should be clearly defined by
the point of determination (POD) and not the proposed point of
generation (POG). The commenters added that the POG concept is not
defined or explained within either the VCM NESHAP or the proposed PVC
MACT. Other MACT standards related to chemical process industries
provide for sampling at the POD and have exemptions in the rule related
to the definition of wastewater.
    Response: We agree with the commenters that it is not feasible to
collect wastewater resulting from maintenance activities at PVC
facilities such that it could be contained and routed to a wastewater
treatment system. We disagree that maintenance wastewater generation
activities are non-routine. We maintain that maintenance activities at
PVC facilities are routine, but those activities result in the
generation of wastewater in such a manner that it cannot be collected,
enclosed and routed to a wastewater treatment system or otherwise
managed in a controlled or enclosed system as process wastewater can.
PVC facilities reported a variety of different work practices used for
maintenance wastewater, but did not provide sufficient description or
information necessary to determine the effectiveness of any one work
practice alone or relative to other work practices. Furthermore, these
streams can vary considerably in HAP concentration. Therefore, it is
not feasible to prescribe or enforce an emission standard for
maintenance wastewater and maintenance wastewater streams should be
regulated separately from process wastewater. In the final rule,
maintenance wastewater is not subject to the same requirements as
process wastewater but instead is subject to work practice standards.
We are incorporating into the final rule the maintenance wastewater
work practice requirements used in other EPA standards, such as the
HON. These work practice standards include preparing a description of
maintenance procedures for management of wastewater generated from the
emptying and purging of equipment in the process during temporary
shutdowns for inspections, maintenance, and repair and during periods
which are not shutdowns. As in the HON, facilities can effectively
implement these work practices to prevent or mitigate the

emissions of HAP from wastewater generated during maintenance
activities. We also agree that certain safety related activities that
may generate a wastewater stream not be subject to the requirements for
process wastewater. Therefore, we have added separate requirements in
the final rule for maintenance wastewater streams. Furthermore, we have
clarified that certain safety-related streams are not considered
wastewater. These two revisions in the final rule are consistent with
wastewater provisions in other MACT standards, such as the HON and MON.
We have also removed all terminology related to ``point of generation''
and ``point of determination.'' These terms created confusion for
determining compliance with the standards. The final rule includes
simplified language regarding where process wastewater streams must be
tested to determine if treatment is required to meet the process
wastewater limits. In the final rule, we are requiring that wastewater
be measured immediately as it leaves a piece of process equipment and
before being mixed with any other process wastewater stream. We have
also clarified that the limits must be met before the process
wastewater stream is discharged from the PVCPU.
5. Heat Exchange Systems
    Comment: Several commenters stated that the proposed heat exchange
systems monitoring methods are more restrictive than other 40 CFR part
63 NESHAP. The commenters suggested that the EPA broaden proposed leak
testing and compliance requirements for cooling water supply (in
closed-loop recirculation systems) and required heat exchange systems.
The commenters identified several alternate compliance methods: (1) EPA
Method 107, which focuses on vinyl chloride, not HAP, be included as a
compliance option. Commenters contended that EPA Method 107, which is
conducted on-site, allows for fast results (24 hours, while EPA SW-846
Method 8021B tests can take a week) and quicker repairs to any leaking
exchange systems; (2) EPA SW-846 Method 8260B, which commenters said
should replace EPA SW-846 Method 8021B. Commenters stated that EPA SW-
846 Method 8260B has a more comprehensive target chemical list; test
laboratories no longer have the equipment or personnel capable of
performing EPA SW-846 Method 8021B; and EPA SW-846 Method 8021B is not
incorporated by reference in 40 CFR 63.14 as is the TCEQ Modified El
Paso Method.
    Response: The leak action level for heat exchange systems is not an
independent limit on emissions, but rather is used as an indicator that
there may be a leaking component and as a trigger level to take further
action to remedy the leak. As discussed in the preamble to the proposed
rule, the leak action level and associated repair requirements for heat
exchange systems are work practice standards under section 112(h) of
the CAA and not numerical emission limits, similar to requirements
applicable to equipment leaks. The proposed leak action levels and
monitoring frequencies were established based on the information
provided to us in responses to our August 21, 2009, CAA section 114
survey and testing request of the PVC industry and subsequent requests
by us of the industry requesting clarification on heat exchange system
monitoring practices used in the industry.
    At proposal, we required measurement of total strippable VOC for
detecting leaks of HAP into the cooling water, which are ultimately
emitted downstream. Based on comments received, we have added an option
for facilities to monitor their heat exchange systems using EPA Method
107, for vinyl chloride to monitor for leaks of total strippable VOC
into cooling water. Vinyl chloride is the primary raw material in the
manufacture of PVC and is present in all process streams. Therefore, if
either total strippable VOC or vinyl chloride leaks are detected,
repair of the leaks will control the leaks for all HAP. The process
streams are cooled by cooling water in non-contact heat exchangers. If
there is a leak of a process stream into the cooling water, for
example, through a broken heat exchanger tube bundle, vinyl chloride
concentrations would increase in the cooling water. A leaking process
stream that contains other HAP in addition to vinyl chloride would also
leak those other HAP into the cooling water. In a recirculating heat
exchange system that contains a cooling tower, the cooling water is
exposed to the atmosphere at the cooling tower. It is sufficient to
establish a leak action level for heat exchange systems at PVC
facilities based on a level of vinyl chloride that, if detected in the
cooling water, would indicate a leak of the process stream and all HAP
contained in that process stream into the system. Therefore, we
determined that for this industry, vinyl chloride is also an
appropriate indicator to determine if there is a leak in a heat
exchange system. Furthermore, EPA Method 107 is an established method
for the analysis of vinyl chloride in wastewater samples.
    Our approach at proposal to determining a MACT floor for heat
exchange systems was to calculate the average (arithmetic mean) leak
action level from the five reported lowest leak action levels to
determine the floor for existing sources, and the single lowest leak
action level to determine the floor for new sources. Similarly, we
looked at the range of monitoring frequencies and selected the median
frequency from nine heat exchange systems for existing sources and the
most frequent monitoring period for new sources. We have revised the
leak action level at the MACT floor for existing sources based on the
median leak action level for total strippable VOC from the top five
lowest leak action levels reported. Similar to our approach to
determining the MACT floor for equipment leaks, it is appropriate to
evaluate the median of leak action levels instead of calculating the
arithmetic mean. We determined that the leak action level for total
strippable VOC for the existing source MACT floor is 50 ppbw. The
lowest leak action level reported was also 50 ppbw and represents the
revised MACT floor leak action level for new sources. Therefore, in the
final rule, the leak action level for total strippable VOC in cooling
water is 50 ppbw with monthly monitoring, for both existing and new
sources. The methods used by facilities to monitor for VOC include the
TCEQ Modified El Paso Method and EPA Method 624. In the final rule, we
have revised the cooling water monitoring method from EPA SW-846 Method
8021B to EPA Method 624, but we have not changed the option to monitor
using the TCEQ Modified El Paso Method.
    To develop a leak action level for vinyl chloride, we looked at the
leak action levels and monitoring frequencies reported by facilities
that perform vinyl chloride monitoring using EPA Method 107. We
determined a vinyl chloride leak action level based on the median leak
action level reported by facilities that monitor for vinyl chloride.
Those leak action levels range from 50 ppbw to 5,000 ppbw with
monitoring frequencies between monthly and quarterly. To determine the
MACT floor level of control, we conducted an analysis similar to the
analysis conducted for equipment leaks; an analogous emission source
that is fugitive in nature where control is a work practice and not an
emission limit. The existing source MACT floor level of control for
equipment leaks was calculated using the average (median) level of
control of work practices at the best-performing five sources. We

determined that the median leak action level for heat exchange systems
was 50 ppbw. The MACT floor analysis results in a leak action level for
vinyl chloride for existing sources of 50 ppbw with monthly monitoring.
The lowest leak action level reported was also 50 ppbw and represents
the revised MACT floor for new sources. Therefore, in the final rule,
the leak action level for total strippable VOC in cooling water is 50
ppbw with monthly monitoring, for both existing and new sources. This
analysis is documented in the memorandum, Revised Maximum Achievable
Control Technology (MACT) Floor Analysis for the Polyvinyl Chloride and
Copolymers (PVC) Production Source Category, and is available in the
docket.
6. Other Emission Sources
    Comment: One commenter stated that in the preamble to the proposed
rule, the EPA has indicated that for ``other emission sources,''
requirements from part 61 NESHAP constituted the MACT floor level of
control and that, in turn, was used to set the proposed limits, which
requires complying with a vinyl chloride percent reduction. However,
the commenter added, the rule requires sources to comply with a total
HAP percent reduction, while the preamble only requires sources to
comply with a vinyl chloride percent reduction. The commenter contended
that sources have been using a method for sampling and detecting vinyl
chloride for years, and measuring total HAP will introduce an
additional layer of complexity to the compliance requirement. The
commenter requested that the EPA review the rule language and make it
consistent with the preamble language by replacing total HAP with vinyl
chloride.
    Response: In the final rule, as in the proposed rule, we are
requiring work practices that require venting the emissions from
process components and equipment through a closed vent system to a
control device prior to opening to minimize emissions. This is
typically achieved by sweeping the component or equipment several times
with nitrogen to reduce the concentration of HAP in the vapor space of
the component or equipment. These work practices will reduce emissions
of all HAP present in the component or equipment prior to opening. In
the final rule we are setting standards for this emission source based
on vinyl chloride because the part 61 NESHAP, which constitutes the
MACT floor level of control for reactor and equipment openings,
requires work practices to specifically control vinyl chloride
emissions. It is appropriate to continue to set the standards based on
vinyl chloride because it will always be present at this emission
point, and controlling it will control all other HAP.
    Comment: Commenters stated that gasholders should not be regulated
as storage vessels, but should be considered as surge control vessels,
due to their process functions. Specifically, commenters contended that
based on the CAA liquid storage definitions and associated
requirements, gasholders do not meet the definitions of ``fixed roof''
storage vessel or ``floating roof'' storage vessel and, thus,
recommended that gasholders be defined as surge control vessels in 40
CFR 63.12005. One commenter also agreed with the EPA that gasholder
seal water should not be regulated as wastewater.
    The commenters stated that it is impractical to measure gasholder
fugitive emissions or route them to a stack, thus work practices should
be used to control these gasholder emissions. One commenter recommended
that the EPA regulate PVC MACT gasholders in the same way as other
surge control vessels at 40 CFR part 63, subpart H. The commenters
stated that the PVC MACT standard for gasholders should be a
combination of equipment control and procedural requirements. The
commenter described studies undertaken to determine the feasibility of
certain control technologies like the use of floating objects to cover
the water seal, finding that though these approaches can reduce
emissions, they have drawbacks as well, and thus should be used in
combination with procedural standards.
    One commenter provided information related to emissions and
controls for gasholders, as requested by the EPA in the preamble. The
commenter stated that gasholders are important for safety and stability
of the operation in the PVC process, with the process equipment
specifically designed around gasholders to maintain safe pressure and
gas flow to the closed vent and vinyl chloride recovery systems.
According to the commenter, any changes to the design of the existing
system could compromise safety procedures and would impose a burdensome
capital investment. Finally, the commenter recommended the use of
floating objects, such as balls, hallow disks, an oil layer or rubber
mats, in the gasholder water seal for emissions reductions, because it
is a flexible system that provides a consistent degree of control
without creating additional waste management concerns.
    Response: In the proposed rule, we requested comment on techniques
to control emissions from gasholders. We reviewed the information
submitted by the industry and have concluded that it is not feasible to
prescribe or enforce an emission standard for emissions of vinyl
chloride or other HAP from the water seal and the outside of the
floating bell on gasholders. For PVC facilities that have gasholders,
they are an integral part of the vinyl chloride recovery process and
are connected to the closed vent system that collects and routes
process vent emissions from process components to the vinyl chloride
recovery system. After vinyl chloride recovery, any remaining process
vent gasses are routed through the closed vent system to a control
device. There are, however, emissions from gasholders that originate
from the water seal and the outer portion of the floating bell that are
fugitive in nature. The water seal contacts vinyl chloride and other
HAP contained in the gasholder, and thus, there is the potential to
emit HAP from the water in the gasholder seal and the thin film of
water that accumulates on the outer surface of the floating bell. It is
not technically practicable to route these emissions into or through a
conveyance designed and constructed to capture and control them to an
enforceable emission limit. Therefore, in the final rule, we are
promulgating a work practice and equipment standard consistent with the
provisions of section 112(h) of the CAA. In the final rule, we are
requiring facilities to install and maintain floating objects on the
surface of the gasholder water seal to minimize emissions of vinyl
chloride and other HAP. We are also requiring facilities to develop a
standard operating procedure for each gasholder to ensure that the
floating objects are properly maintained and that emissions are
minimized.

G. Initial and Continuous Compliance and Recordkeeping and Reporting

    Comment: Three commenters stated that the EPA should remove CDD/CDF
CEMS from the rule. The commenters contended that CDD/CDF CEMS
technology is not well developed. One commenter stated that an EPA CDD/
CDF CEMS study noted that, within the range of 1-10 ng/dscm, TEQ
relative accuracy was reported between 23 percent and 75 percent. The
commenter contended that the technology would not be useful with such a
wide range of relative accuracy at the proposed limit. Another
commenter stated that the technology is not commercially available in
the United States. Another commenter indicated that monitors in use are
mainly in other countries. Another commenter added that several of the
available monitors are not continuous because they are not real

time and require using a third party lab for results.
    Response: We agree with the commenter on the availability of CEMS
for CDD/CDF. CEMS for CDD/CDF and HCl are still being developed and the
EPA does not have specifications for the technology currently. In the
final rule, we have removed the requirement for CDD/CDF and HCl CEMS,
but have retained them as an option for existing and new sources once
performance specifications have been promulgated.

H. Area Sources

    Comment: One commenter stated that, if the PVC MACT and GACT are
combined, the EPA needs to fully consider the cost of the MACT on area
sources and modify the requirements to minimize the burden on area
sources. The commenter stated that GACT standards required by CAA
section 112(d)(5) are different from MACT standards under CAA section
112(d)(3) and, though the technologies employed in these facilities are
similar, the EPA has not performed the required economic analysis in
setting GACT. One commenter stated that, given the burdens on reduced
workforces at smaller facilities, scaled-back requirements such as
reduced stack testing frequency or reduced CPMS requirements are
warranted and will have no negative impact on air emissions or
compliance at area source facilities. The commenter added that the
economic impact of the proposed PVC MACT on area sources makes these
measures necessary for the facilities to remain financially viable.
    One commenter stated that the proposed GACT standard for process
vents for vinyl chloride and CDD/CDF are not appropriate or cost
effective, based on small emissions reduction and high cost calculated
in the EPA's analysis. The commenter added that these limits are
redundant since total organic HAP includes vinyl chloride and CDD/CDF
and, thus, they contended that the vinyl chloride standards should be
eliminated.
    One commenter made several comments regarding the pollutants
proposed for regulation for area sources under GACT. The commenter
stated that regulation of ``total HAP'' and ``CDD/CDF'' under the area
source GACT standard is not warranted because, although the agency has
discretion to regulate all urban HAP for area sources, total HAP is not
an urban HAP (they contend that classifying total HAP as an urban HAP
would make the list meaningless), and CDD/CDF is not a HAP at all
(thus, the EPA has no authority to regulate CDD/CDF under CAA section
112). Furthermore, the commenter contended that control technologies
already used by CertainTeed to control vinyl chloride also achieve
control of individual organic HAP. For CDD/CDF, the commenter pointed
out that the EPA's own analysis showed that the proposed regulation
would achieve little, if any, reductions. The commenter concluded that
there is no benefit to establishing a standard for total HAP or CDD/
CDF. The commenter added that the regulation of HCl under the area
source GACT standard is not warranted either. They contended that,
because the EPA has the discretion to revise the GACT standard only as
necessary, the EPA must first determine that regulation of HCl is
necessary. Instead, the commenter stated that the EPA seeks to regulate
HCl emissions and suggests that such regulation is ``appropriate''
simply based on the fact that such emissions ``are generated.'' In
light of this, the commenter concluded that the proposed GACT standards
for HCl should not be finalized.
    Response: We proposed GACT standards for PVC area sources based on
the proposed MACT standards for major sources. For the final rule, we
have updated our analysis of area source GACT, considering comments
received, including our analysis of cost considerations. Our revised
GACT analysis assesses each PVC emission point (e.g., process vents,
stripped resin, equipment leaks, etc.) individually, for both existing
and new sources, to determine the appropriate level of control,
considering cost and emission reduction. The GACT analysis was
conducted for the same subcategories as major sources.
    Section 112(d)(5) of the CAA authorizes the EPA to promulgate
standards or requirements for area sources ``which provide for the use
of generally available control technologies or management practices
[GACT] by such sources to reduce emissions of hazardous air
pollutants.'' We issued such standards for PVC area sources in 2007.
    Under CAA section 112(d)(6), we are required to ``review, and
revise as necessary (taking into account developments in practices,
processes, and control technologies), emission standards promulgated
under this section no less often than every 8 years.'' With this
rulemaking, we are fulfilling our obligation to review and revise, as
necessary, the PVC Production area source standards. The 2007 NESHAP
for PVC Production area sources (40 CFR part 63, subpart DDDDDD) are
based on GACT. The area source NESHAP set emission limits only for
vinyl chloride, which was the pollutant for which we needed the PVC
production area source category to meet our 90-percent obligation in
CAA sections 112(c)(3) and (k)(3)(B). In this final rule, we are
tightening emission standards for vinyl chloride under CAA section
112(d)(6). We are also establishing emission standards for CDD/CDF and
THC for process vents (with an alternative compliance limit for total
organic HAP) and total non-vinyl chloride organic HAP for stripped
resins and wastewater under CAA section 112(d)(5). We are also
requiring generally available management practices for PVC area sources
under CAA section 112(d)(5). We are not setting separate limits for HCl
from process vents at PVC area sources.
    In this final rule, we have determined that area source emission
limits should be set for THC as a surrogate for organic HAP, along with
limits for CDD/CDF and vinyl chloride, for process vents, and for total
non-vinyl chloride organic HAP and vinyl chloride for stripped resins
and process wastewater. We discussed earlier in this preamble our
specific reasons for establishing emissions limits for these pollutants
from PVC facilities. We also determined that it is appropriate to
provide a total organic HAP limit as an alternative to the THC limit
for process vents at area sources, just as we did for PVC major
sources. We disagree with the commenter who states that the EPA should
not establish a total organic HAP limit (or total non-vinyl chloride
organic HAP limit for stripped resins and process wastewater) because
total organic HAP is not an urban HAP. We note that the commenter
concedes that the agency has discretion to regulate all urban HAP for
area sources. The commenter also does not dispute that PVC facilities
emit several organic urban HAP, beyond vinyl chloride.
    Moreover, as the EPA has explained in other area source rules, the
agency has authority to regulate all HAP, not only urban HAP, from area
source categories listed pursuant to CAA section 112(c)(3). See, e.g.,
Chemical Manufacturing Area Sources NESHAP proposed rule, 73 FR 58352,
58358, October 6, 2008, and final rule, 74 FR 56008, 56017-18, October
29, 2009).\4\

We are setting emission limits for total organic HAP for process vents
(and total non-vinyl chloride organic HAP for stripped resin and
process wastewater) for several reasons. First, the compliance measures
that we expect sources to adopt to meet the final limits are equally
effective at controlling emissions of non-urban organic HAP as urban
organic HAP. Second, there is little, if any, additional cost for
implementing those compliance measures at PVC process vents, stripped
resin and process wastewater. Third, we are applying the standards to
total organic HAP or total non-vinyl chloride organic HAP because many
of the area sources emit a significant amount of non-urban organic HAP
in addition to urban organic HAP, for example, the nationwide ratio of
total organic HAP to urban organic HAP at affected area sources is more
than 3 to 1. Finally, we believe our approach is consistent with
certain industry comments that support using total organic HAP limits
as the best means of achieving HAP emission reductions under CAA
section 112(d) without fundamentally changing the PVC product being
produced for sale by these facilities.
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    \4\ CAA section 112(d)(5) states that for area sources listed
pursuant to CAA section 112(c), the Administrator may, in lieu of
CAA section 112(d)(2) ``MACT'' standards, promulgate standards or
requirements ``applicable to sources'' which provide for the use of
GACT or management practices ``to reduce emissions of hazardous air
pollutants.'' This provision does not limit the agency's authority
to regulating only urban HAP emissions for which the category was
listed under CAA section 112(c)(3).
---------------------------------------------------------------------------

    We have determined that area sources will not have to install
different controls or implement different compliance strategies and
will incur little, if any, additional cost to comply with the standards
for total organic HAP (and total non-vinyl chloride organic HAP).
Moreover, the commenter does not refute that the expected compliance
measures in the PVC industry are equally effective at removing non-
urban organic HAP, as urban organic HAP. For all of these reasons, we
are applying these standards to process vents, stripped resin and
process wastewater at PVC area sources. In addition, the comment that
we should limit area source standards to only the urban organic HAP
conflicts with other industry comments advocating THC as a surrogate.
As we explained previously in preamble section V.C, THC is a reasonable
surrogate for controlling all organic HAP from PVC process vents.
However, while control of THC ensures control of all organic HAP (as
does the total organic HAP alternative), THC cannot differentiate
between organic HAP that is urban HAP and organic HAP that is not urban
HAP. The commenter's statement further conflicts with our determination
that a total non-vinyl chloride organic HAP emission limit is an
appropriate limit for stripped resins and process wastewater (see
discussion at preamble section V.C).
    We disagree with the commenter's statement that CDD/CDF is not a
HAP. We are authorized to regulate the CDD/CDF class of HAP. While
dibenzofuran and 2,3,7,8-TCDD are identified by name as HAP in CAA
section 112, all CDD/CDF are polycyclic organic matter and, as such, we
have the authority to regulate these compounds.
    We disagree with the commenter who stated reduced stack testing
frequency or reduced CPMS requirements are warranted for area sources.
We believe that these requirements are necessary to demonstrate
compliance with the emission limits regardless of the size of the
facility or the magnitude of emissions. Therefore, the same testing and
monitoring requirements apply to both major and area sources. Since the
PVC-only and PVC-combined process vent area source limits are based on
the facility in each subcategory, no additional controls would be
needed and no emission reductions would occur. Monitoring,
recordkeeping and reporting would be the only costs. (See Tables 16 and
17 of this preamble.) We agree with the commenter that total organic
HAP includes vinyl chloride and dioxins and furans, but we disagree
that vinyl chloride standards should be eliminated, since vinyl
chloride emissions limits already apply to PVC facilities under 40 CFR
part 61, and they serve as a check on a unit's recovery process
efficiency and since physical measurement of vinyl chloride from
process vents occurs only every 5 years. In determining what
constitutes GACT for this final rule, we considered the control
technologies and management practices that are generally available to
PVC area sources by examining relevant data and information, including
information collected from PVC area sources. We also considered the
control measures applicable to PVC major sources to determine if the
control technologies and management practices are transferable and
generally available to area sources. As part of the GACT determination,
we considered the costs and economic impacts of available control
technologies and management practices on area sources which are
documented in the technical memorandum, Generally Achievable Control
Technology (GACT) Analysis for Area Sources in the Polyvinyl Chloride
and Copolymers (PVC) Production Source Category, which is available in
the docket.
    Under CAA section 112(d)(5), the EPA can promulgate standards or
requirements for area sources ``which provide for the use of generally
available control technologies or management practices [GACT] by such
sources to reduce emissions of hazardous air pollutants.'' Additional
information on GACT is found in the Senate report on the legislation
(Senate Report Number 101-228, December 20, 1989), which describes GACT
as:

    * * * methods, practices and techniques which are commercially
available and appropriate for application by the sources in the
category considering economic impacts and the technical capabilities
of the firms to operate and maintain the emissions control systems.

    Consistent with the legislative history, we can consider costs and
economic impacts in determining GACT.
    Determining what constitutes GACT involves considering the control
technologies and management practices that are generally available to
the area sources in the source category. We also consider the standards
applicable to major sources in the analogous source category to
determine if the control technologies and management practices are
transferable and generally available to area sources. In appropriate
circumstances, we may also consider technologies and practices at area
and major sources in similar categories to determine whether such
technologies and practices could be considered generally available for
the area source categories at issue.
    We determined new and existing area source standards for each
emission point by evaluating the current (also referred to as baseline)
level of control and control options beyond the current level of
control.
    For each emission point, we determined the current level of control
for existing area sources, incorporating variability. If no area source
currently exists in the category or subcategory, the least controlled
major source, in each subcategory for each regulated pollutant, as
applicable, was analyzed as the baseline level of control for GACT. The
only two existing PVC area sources that we are aware of produce bulk
resin and suspension resin, respectively. No existing area sources
produce dispersion resin, suspension blending resin or copolymer resin.
However, if an existing PVC major source is able to become a synthetic
area source, e.g., by taking a federally enforceable limit on its
potential to emit, before the first compliance date of this rule, it
would be subject to area source rather than major source PVC NESHAP
requirements. Therefore, in order to develop GACT standards for other
stripped resin subcategories, we determined the baseline level of
control for these subcategories in which there is

no existing area source to be equivalent to that of the least
controlled major source, i.e., for the dispersion, suspension blending
and copolymer subcategories for stripped resins. For the suspension
blending and copolymer subcategories, there is only one major source.
So for these subcategories of stripped resin, the level of control of
the least controlled major source was the same as the major source MACT
floor level of control. In addition, gasholders are the only emission
source that are located at major sources, but not located at area
sources. Therefore, we determined that the baseline level of control
for gasholders is equivalent to that of the least controlled PVC major
source with a small gasholder. We believe that all future possible
existing area sources should be able to achieve these levels of
control, as we predict that most, if not all, such sources will be
major sources that limit their potential to emit to levels below the
major source thresholds before the first substantive compliance date of
this rule. See 42 U.S.C. 112(a)(1); 40 CFR 63.2 (definition of
``potential to emit''). For equipment leaks, heat exchange systems and
storage vessels, we determined that the level of control was the same
as the major source work practice standards.
    We are also establishing new source GACT. We have data from the two
existing area source facilities, and those facilities form the basis of
our new source GACT analysis. For the PVC-combined process vents, PVC-
only process vents, bulk resin and suspension resin subcategories, we
have data from one area source facility. For the other emission points
(except for dispersion resin, suspension blending resin and copolymer
resin discussed in the previous paragraph) both facilities are
equivalent in terms of their current level of control. For equipment
leaks, the CertainTeed Lake Charles facility and the OxyVinyls Deer
Park facility both comply with 40 CFR part 61, subpart V. Therefore, we
find that the level of control for new area sources is equivalent to
the level of control for existing area sources.
    Control options beyond the current or baseline level of control for
existing sources were analyzed on a basis of cost effectiveness. We
determined the emission reductions, if any, associated with existing
PVC area sources meeting levels of control more stringent than the
current or baseline level of control. We then estimated the annual cost
of testing, monitoring, recordkeeping and reporting, and any operating
and maintenance costs associated with control devices required to meet
the more stringent control levels. We developed a cost- effectiveness
estimate by dividing the annual cost of the more stringent control
level with the annual emission reduction. The control options analyzed
are as follows:
    For PVC-only and PVC-combined process vents at new and existing
area sources, for each subcategory, we analyzed two additional control
options beyond the current level of control. The first option was
requiring the current level of control, as discussed above, and the
testing and monitoring requirements for process vents at existing major
sources. The same types of controls are used at both existing area and
major sources. The testing and monitoring necessary to ensure
compliance with the emission limits and to ensure proper operation of
the control device are the same regardless of the size of the control
device. The second option was requiring meeting the emission limits for
existing major sources in addition to the testing and monitoring
requirements for existing major sources.
    For PVC-only process vents at new and existing area sources, we
determined that the second option was not cost effective; instead, we
concluded that the first option was appropriate. We determined that the
major source testing and monitoring requirements are appropriate and
necessary to ensure that area sources are in compliance with the
process vent standards, whether those required standards are the
current level of control or major source standards. Therefore, we are
requiring PVC-only and PVC-combined process vents at new and existing
area sources to comply with GACT by meeting the current level of
control and the testing and monitoring requirements for existing major
sources.
    For stripped resins at new and existing PVC area sources, we
analyzed two additional control options beyond the current or baseline
level of control for each subcategory. The first option was requiring
the current or baseline level of control and the testing and monitoring
requirements for stripped resins at existing major sources. The second
option was meeting the emission limits for existing major sources in
addition to the testing and monitoring requirements for existing major
sources. For the bulk and suspension resin subcategories, we are
setting the stripped resin limits for new and existing area sources
equivalent to their current level of control, accounting for
variability, and testing and monitoring requirements for major sources
for each stripped resin subcategory. For dispersion resins, GACT is
based on the baseline level of control, i.e., the least controlled
major source and limits were developed for dispersion resins based on
data from that source. For the suspension blending and copolymer resin
subcategories, we are requiring the emission limits for existing major
sources since there was only one source in each of these subcategories
(i.e., the baseline level of control was the level of control the
existing major source) in addition to the testing and monitoring
requirements for existing major sources. Similar to process vents, we
determined that it is appropriate to require testing and monitoring
requirements for major sources to ensure compliance.
    For process and maintenance wastewater at new and existing PVC area
sources, we analyzed three additional control options beyond the
current baseline. The first option was requiring the current level of
control and the testing and monitoring requirements for wastewater at
existing major sources. The second option was meeting the emission
limits for existing major sources in addition to the testing and
monitoring requirements for wastewater at existing major sources. The
third option was meeting the emission limits for new major sources in
addition to the testing and monitoring requirements for wastewater at
existing major sources. We determined that the second option of
emission limits for existing major sources was less stringent than
(i.e., not beyond) the current baseline for new and existing area
sources. We determined that the third option of emission limits for new
major sources were not cost effective for new or existing PVC area
sources. Therefore, we are requiring process and maintenance wastewater
at new and existing area sources to comply with GACT by meeting the
current baseline and the major source testing and monitoring
requirements. Similar to process vents, we determined that it is
appropriate to require testing and monitoring requirements for major
sources and necessary to ensure that area sources are in compliance
with the process and maintenance wastewater standards.
    For equipment leaks and for heat exchangers at new and existing PVC
area sources, we analyzed one additional control option beyond the
current level of control. The additional option was meeting the
emission standards for equipment leaks and for heat exchangers at
existing major sources. We determined that the emission standards for
equipment leaks and heat exchangers at existing major sources are cost
effective for new and existing area sources. Therefore, we are
requiring new and existing area sources to comply with GACT by meeting
the

equipment leak and heat exchanger standards at existing major sources.
    For storage tanks at new and existing PVC area sources, we analyzed
one additional control option beyond the current baseline. The
additional option was meeting the emission standards for storage tanks
at existing major sources. We determined the emission standards for
storage tanks at existing major sources are cost effective for new and
existing area sources. Therefore, we are requiring new and existing
area sources comply with GACT by meeting the emission standards for
existing major sources.
    For other emission sources, the current level of control is
emission standards for reactor and other equipment openings equivalent
to the requirements in 40 CFR part 61, subpart F, which is also
equivalent to the major source level of control. We analyzed an
additional option for gasholders equivalent to the emission standards
for gasholders at major sources. The option was determined to be cost
effective for new and existing area sources. Therefore, we are
requiring that new and existing area sources comply with GACT by
meeting the emission standards for gasholders and reactor openings at
major sources.
    Tables 16 and 17 present a summary of the control options analysis
for new and existing area sources.

                     Table 16--Summary of Control Option Analysis for Existing Area Sources
----------------------------------------------------------------------------------------------------------------
                                                                         Incremental
                                              Control option analyzed    annual cost    Emission        Cost
              Emission point                  beyond current level of         of       reductions  effectiveness
                                                      control             compliance  (tpy--total   ($/ton total
                                                                            ($/yr)        HAP)          HAP)
----------------------------------------------------------------------------------------------------------------
PVC-only process vents...................  Major Source Testing and           10,890            0         (\a\)
                                            Monitoring.
                                           Existing Major Source             180,245        0.257       701,814
                                            emission standards,
                                            monitoring and testing.
PVC- combined process vents..............  Major Source Testing and           10,890            0         (\a\)
                                            Monitoring.
                                           Existing Major Source              10,890            0         (\a\)
                                            emission standards,
                                            monitoring and testing.
Stripped resins (all subcategories)......  Major Source Testing and           10,615            0         (\a\)
                                            Monitoring.
                                           Existing Major Source              10,615            0         (\a\)
                                            emission standards,
                                            monitoring and testing.
Process and maintenance wastewater.......  Major Source Testing and           19,777            0         (\a\)
                                            Monitoring.
                                           Existing Major Source              19,777            0         (\a\)
                                            emission standards,
                                            monitoring and testing.
                                           New Major Source emission       2,996,390         12.2       245,516
                                            standards, monitoring and
                                            testing.
Equipment leaks..........................  Existing Major Source              72,525         9.29         7,807
                                            emission standards,
                                            monitoring and testing.
Heat exchangers..........................  Existing Major Source              25,529         15.1         1,691
                                            emission standards,
                                            monitoring and testing.
Other emission sources...................  Existing Major Source               3,108            0    \b\ $4,921
                                            emission standards,
                                            monitoring and testing.
Storage tanks............................  Existing Major Source               3,108            0    \c\ 2,000-
                                            emission standards,                                          12,000
                                            monitoring and testing.
----------------------------------------------------------------------------------------------------------------
\a\ Option does not result in emission reductions; therefore, a cost effectiveness was not applicable.
\b\ Emission reductions and costs were calculated for retrofitting a model small gasholder with floating objects
  to reduce emissions from the gasholder water seal. The results of the analysis showed that cost effectiveness
  was equal to $4,921 per ton of vinyl chloride reduced. We are not aware of any gasholders operated at existing
  PVC area sources; therefore no emission reductions are shown.
\c\ Emissions reductions and costs were calculated for retrofitting 40 CFR part 63, subpart WW controls on model
  fixed roof tanks meeting 40 CFR part 60, subpart Kb vapor pressure and size parameters. The results of the
  analysis showed that cost effectiveness ranged from $2,000 to $12,000 per ton of HAP reduced by this option
  depending on the number of turnovers assumed. Based on information submitted by PVC production facilities, no
  storage vessels from affected sources that meet the capacity levels storing materials that meet the vapor
  pressure levels were identified. Therefore, it was assumed that no storage vessels meeting capacity levels
  storing materials that meet the vapor pressure levels would be constructed at a new source.
$/yr--dollars per year.
tpy--tons per year.
$/Ton Total HAP--dollars per ton of total HAP.

                        Table 17--Summary of Control Option Analysis for New Area Sources
----------------------------------------------------------------------------------------------------------------
                                                                         Incremental
                                              Control option analyzed    annual cost    Emission        Cost
              Emission point                  beyond current level of         of       reductions  effectiveness
                                                      control             compliance  (tpy--total   ($/ton total
                                                                            ($/yr)        HAP)          HAP)
----------------------------------------------------------------------------------------------------------------
PVC-only process vents...................  Major Source Testing and           10,890            0         (\a\)
                                            Monitoring.
                                           Existing Major Source             180,245        0.257       701,814
                                            emission standards,
                                            monitoring and testing.
PVC-combined process vents...............  Major Source Testing and           10,890            0         (\a\)
                                            Monitoring.
                                           Existing Major Source              10,890            0         (\a\)
                                            emission standards,
                                            monitoring and testing.
Stripped resins (all subcategories)......  Major Source Testing and           10,615            0         (\a\)
                                            Monitoring.
                                           Existing Major Source              10,615            0         (\a\)
                                            emission standards,
                                            monitoring and testing.
Process and maintenance wastewater.......  Major Source Testing and            9,888            0         (\a\)
                                            Monitoring.
                                           Existing Major Source               9,888            0         (\a\)
                                            emission standards,
                                            monitoring and testing.
                                           New Major Source emission       1,988,368         8.91       223,169
                                            standards, monitoring and
                                            testing.
Equipment leaks..........................  Existing Major Source              36,263         4.64         7,807
                                            emission standards,
                                            monitoring and testing.
Heat exchangers..........................  Existing Major Source              12,764         11.4         1,117
                                            emission standards,
                                            monitoring and testing.
Other emission sources...................  Existing Major Source               3,032        0.616         4,922
                                            emission standards,
                                            monitoring and testing.

Storage tanks............................  Existing Major Source               1,554            0    \b\ 2,000-
                                            emission standards,                                          12,000
                                            monitoring and testing.
----------------------------------------------------------------------------------------------------------------
\a\ Option does not result in emission reductions; therefore, a cost effectiveness was not applicable.
\b\ Emissions reductions and costs were calculated for retrofitting 40 CFR part 63, subpart WW controls on model
  fixed roof tanks meeting 40 CFR part 60, subpart Kb vapor pressure and size parameters. The results of the
  analysis showed that cost effectiveness ranged from $2,000 to $12,000 per ton of HAP reduced by this option
  depending on the number of turnovers assumed. Based on information submitted by PVC production facilities, no
  storage vessels from affected sources that meet the capacity levels storing materials that meet the vapor
  pressure levels were identified. Therefore, it was assumed that no storage vessels meeting capacity levels
  storing materials that meet the vapor pressure levels would be constructed at a new source.
$/yr--dollars per year.
tpy--tons per year.
$/Ton Total HAP--dollars per ton of total HAP.

    A detailed discussion of these options and the cost and impacts
estimated for them is found in the memorandum, Generally Achievable
Control Technology (GACT) Analysis for Area Sources in the Polyvinyl
Chloride and Copolymers (PVC) Production Source Category, and is
available in the docket. The results of the GACT analysis are presented
in sections VI.A and VI.B of this preamble.
    The summary of the area source requirements in the final rule is
discussed in section IV.I of this preamble.
    Comment: One commenter disagreed with the EPA's proposed equipment
leak standards. The commenters stated that the EPA's estimates of
baseline fugitive emissions are not valid and not representative of
CertainTeed's actual measured fugitive emissions from equipment leaks,
because EPA estimated the emissions from equipment leaks by applying
average emission factors instead of relying on actual measured data.
The commenter contended that because of these estimates, the EPA
grossly overestimated the level of fugitive emission reductions. The
commenter concluded that because of these overestimations, the cost of
the proposed Equipment Leak GACT standards cannot be justified by the
potential emission reductions.
    Response: At proposal, we estimated baseline emissions and
reductions for fugitive emissions from equipment leaks using the 1995
EPA Protocol for Equipment Leak Emission Estimates. We agree with the
commenter that the 1995 factors yield conservatively high estimates of
actual emissions. As part of the technology review required by section
112(d)(6) of the CAA, the EPA has developed new emission factors for
equipment leaks that better represent fugitive emissions at chemical
manufacturing processes and petroleum refineries. Emission factors were
developed using facility data from the MON MACT floor development and
the EPA Office of Air Quality and Planning Standards Protocol for
Equipment Leak Emission Estimates. (Please refer to the memorandum in
the docket titled Technology Review for Equipment Leaks for additional
information regarding the development of new emission factors for
equipment leaks.) Although the commenter provided annual fugitive
emissions from equipment leaks for years 2007 through 2010, the
commenter did not provide any equipment leak monitoring records, test
reports or additional documentation supporting their emission
estimates. Therefore, we have chosen to estimate fugitive emissions for
both major and area sources using the updated emission factors for
consistency across all PVCPU. Using updated emission factors and
equipment counts provided by CertainTeed where available, we have
updated the baseline emission estimate for fugitive HAP emissions from
equipment leaks at the CertainTeed facility to 10 tpy. We have also
updated our emissions reduction estimate to 4.64 tpy of HAP as a result
of the facility complying with 40 CFR part 63, subpart UU.
    We have also updated the total capital investment and total
annualized costs of the CertainTeed facility complying with 40 CFR part
63, subpart UU and installing and operating a PRD monitoring system
using equipment counts where provided by the facility. The analysis is
documented in the memorandum titled Generally Achievable Control
Technology (GACT) Analysis for Area Sources in the Polyvinyl Chloride
and Copolymers (PVC) Production Source Category in the PVC docket. The
total cost effectiveness is estimated to equal $6,840 dollars per ton
of total HAP; therefore, we are finalizing the requirements for area
sources to comply with subpart UU and install and operate a PRD
monitoring system.
I. Definitions
    The following definitions have been revised since the proposal:
Batch process vent, conservation vent, continuous process vent, grade,
in HAP service, operating scenario, polyvinyl chloride, PVC production
process unit or PVCPU, polyvinyl chloride copolymer, pressure relief
device, process vent, solution process, type of resin and wastewater.
    We have revised the definition of batch process vent to provide
consistency with our revisions to the definitions of continuous process
vent and process vent and to clarify that batch process vents must be
routed to a closed vent system and control device. We also clarify that
all emission episodes associated with a batch unit operation are part
of the batch process vent. We have also removed language from the
definition that excluded certain types of vents or vents from certain
components or equipment. In the final rule, batch process vent means a
vent from a batch operation from a PVCPU through which a HAP-containing
gas stream has the potential to be released to the atmosphere except
that it is required by this subpart to routed to a closed vent system
and control device. Emissions for all emission episodes associated with
the unit operation(s) are part of the batch process vent. Batch process
vents also include vents with intermittent flow from continuous
operations. Examples of batch process vents include, but are not
limited to, vents on condensers used for product recovery,
polymerization reactors and process tanks.

    We have revised the definition of conservation vent to provide
additional clarification. In the final rule, conservation vent means an
automatically operated (e.g., weight-loaded or spring-loaded) safety
device used to prevent the operating pressure of a storage vessel from
exceeding the maximum allowable working pressure of the process
component. Conservation vents must be designed to open only when the
operating pressure of the storage vessel exceeds the maximum allowable
working pressure of the process component. Conservation vents open and
close to permit only the intake or outlet relief necessary to keep the
storage vessel within permissible working pressures, and reseal
automatically.
    We have revised the definition of continuous process vent to
provide consistency with our revisions to the definitions of batch
process vent and process vent. We also clarify that continuous process
vents must be routed to a closed vent system and control device. In the
final rule, continuous process vent means a vent from a continuous
PVCPU operation through which a HAP-containing gas stream has the
potential to be released to the atmosphere, except that it is required
by this subpart to routed to a closed vent system and control device
and has the following characteristics:
    (1) The gas stream originates as a continuous flow from any
continuous PVCPU operation during operation of the PVCPU.
    (2) The discharge into the closed vent system and control device
meets at least one of the following conditions:
    (i) Is directly from any continuous operation.
    (ii) Is from any continuous operation after passing solely (i.e.,
without passing through any other unit operation for a process purpose)
through one or more recovery devices within the PVCPU.
    (iii) Is from a device recovering only mechanical energy from a gas
stream that comes either directly from any continuous operation or from
any continuous operation after passing solely (i.e., without passing
through any other unit operation for a process purpose) through one or
more recovery devices within the PVCPU.
    We have revised the definition of grade to specify resin ``type''
instead of resin ``classification'' since resins are first classified
by type, and types are further subdivided into grades. We have also
provided an example of a resin grade. In the final rule, grade means
the subdivision of PVC resin that describes it as a unique resin, i.e.,
the most exact description of a type of resin with no further
subdivision. Examples include LMW suspension resins and general purpose
suspension resins.
    We have revised the definition of in HAP service. In the final
rule, in HAP service means that a process component either contains or
contacts a liquid that is at least 5-percent HAP by weight or a gas
that is at least 5 percent by volume HAP, as determined according to
the provisions of 40 CFR 63.180(d). For the purposes of this
definition, the term ``in organic HAP service,'' as used in 40 CFR
63.180(d), means ``in HAP service.'' The provisions of 40 CFR 63.180(d)
also specify how to determine that a process component is not in HAP
service.
    We have revised the definition of polyvinyl chloride to clarify
that it includes homopolymers and copolymers. In the final rule,
polyvinyl chloride means either polyvinyl chloride homopolymer or
polyvinyl chloride copolymer.
    We have revised the definition of polyvinyl chloride and copolymers
production process unit or (PVCPU) to remove components that are
storage tanks or vessels, heat exchange systems, wastewater and
wastewater collection and treatment systems, and add instrumentation
systems. Multiple PVCPU may be located at the same affected source and
share storage tanks, heat exchange systems and process wastewater
treatment systems. Therefore this shared equipment has been removed
from the definition of a PVCPU and is now included in the definition of
the affected source instead of the PVCPU. In the final rule, polyvinyl
chloride and copolymers production process unit or (PVCPU) means a
collection of process components assembled and connected by hard-piping
or duct work, used to process raw materials and to manufacture
polyvinyl chloride and/or polyvinyl chloride copolymers. A PVCPU
includes, but is not limited to, polymerization reactors; resin
stripping operations; resin blend tanks; resin centrifuges; resin
dryers; resin product separators; recovery devices; reactant and raw
material charge vessels and tanks, holding tanks, mixing and weighing
tanks; finished resin product storage tanks or storage silos; finished
resin product loading operations; connected ducts and piping; equipment
including pumps, compressors, agitators, PRD, sampling connection
systems, open-ended valves or lines, valves and connectors and
instrumentation systems. A PVCPU does not include chemical
manufacturing process units, as defined in 40 CFR 63.101, that produce
VCM or other raw materials used in the PVC polymerization process.
    We have revised the definition of polyvinyl chloride copolymer to
clarify that polyvinyl chloride copolymers can also be produced using a
suspension blending process. In the final rule, polyvinyl chloride
copolymer means a synthetic thermoplastic polymer that is derived from
the simultaneous polymerization of vinyl chloride and another monomer,
such as vinyl acetate. Polyvinyl chloride copolymer is produced by
different processes, including, but not limited to, suspension,
dispersion/emulsion, suspension blending and solution processes.
    We have revised the definition of pressure relief device to remove
the condition that devices actuated either by a pressure of less than
or equal to 2.5 pounds per square inch gauge or by a vacuum are not
PRD. In the final rule, pressure relief device means a safety device
used to prevent operating pressures from exceeding the maximum
allowable working pressure of the process component. A common PRD is a
spring-loaded pressure relief valve.
    We have revised the definition of process vent to provide
consistency with our revised definitions of batch process vent and
continuous process vent and miscellaneous vent. In the final rule,
process vent means a vent stream that is the result of the manifolding
of each and all batch process vent, continuous process vent or
miscellaneous vent resulting from the affected facility into a closed
vent system and into a common header that is routed to a control
device. The process vent standards apply at the outlet of the control
device. A process vent is either a PVC-only process vent or a PVC-
combined process vent.
    We have revised the definition of solution processes to specify
that the process produces a polyvinyl chloride copolymer instead of
only a polyvinyl chloride resin. In the final rule, solution process
means a process for producing polyvinyl chloride copolymer resin that
is characterized by the anhydrous formation of the polymer through
precipitation. Polymerization occurs in an organic solvent in the
presence of an initiator where VCM and co-monomers are soluble in the
solvent, but the polymer is not. The PVC copolymer is a granule
suspended in the solvent, which then precipitates out of solution.
Emulsifiers and suspending agents are not used in the solution process.
Copolymer resins produced using the solution process are referred to as
solution resins.

    At proposal, we defined a surge control vessel as part of any
continuous operation. However, based on industry comments, gasholders
meet the definition of a surge control vessel although gasholders may
receive and introduce material into batch processes in addition to
continuous processes. Therefore, we have modified the definition of a
surge control vessel to reflect the definition in 40 CFR part 63,
subpart H and remove the specification that surge control vessels must
be used as part of a continuous operation and introduce material into
continuous operations. We have, however, modified the definition from
40 CFR part 63, subpart H, to specify that surge control vessels are
used within an affected source (and not solely a process unit) since
PVCPU may share gasholders. In the final rule, surge control vessel
means feed drums, recycle drums and intermediate vessels used as a part
of any continuous operation. Surge control vessels are used within an
affected source when in-process storage, mixing or management of flow
rates or volumes is needed to introduce material into continuous
operations. Surge control vessels also include gasholders.
    We have revised the definition of type of resin to include
additional resin types identified by commenters after proposal,
specifically blending types of resin. In the final rule, type of resin
means the broad classification of resin referring to the basic
manufacturing process for producing that resin, including, but not
limited to, suspension, dispersion/emulsion, suspension blending, bulk
and solution processes.
    We have revised the definition of wastewater to mirror definitions
in other chemical sector rules, such as the HON, for consistency as
several facilities are currently subject to multiple wastewater
provisions. We have also specified what is not considered wastewater.
In the final rule, wastewater means process wastewater and maintenance
wastewater. The following are not considered wastewater for the
purposes of this subpart:
    (1) Stormwater from segregated sewers;
    (2) Water from fire-fighting and deluge systems, including testing
of such systems;
    (3) Spills;
    (4) Water from safety showers;
    (5) Samples of a size not greater than reasonably necessary for the
method of analysis that is used;
    (6) Equipment leaks;
    (7) Wastewater drips from procedures such as disconnecting hoses
after cleaning lines; and
    (8) Noncontact cooling water.
    The following definitions have been added to the final rule:
gasholder, hard-piping, heat exchanger exit line, maintenance
wastewater, miscellaneous vent, polyvinyl chloride homopolymer, process
wastewater, process wastewater treatment system, PVC-combined process
vent, PVC-only process vent, suspension blending process, table 10 HAP,
total non-vinyl chloride organic HAP and wastewater stream.
    We have added a definition for polyvinyl chloride homopolymers to
distinguish between homopolymers and copolymers. During the comment
period, industry provided additional resin data distinguishing
homopolymers and copolymers and is based largely on the proposed
definition for polyvinyl chloride. For reasons discussion in section
V.D of this preamble, we have set limits for five subcategories of
resin, including copolymers. Therefore, the new definitions are
necessary to distinguish between homopolymers and copolymers. The
definitions are based on the information provided in comments. In the
final rule, polyvinyl chloride homopolymer means a synthetic
thermoplastic polymer that is derived from the polymerization of vinyl
chloride and has the general chemical structure (-H2CCHCl-
)n. Polyvinyl chloride homopolymer is typically a white
powder or colorless granule. Polyvinyl chloride homopolymers are
produced by different processes, including (but not limited to)
suspension, dispersion/emulsion, blending and bulk processes.
    At proposal, we did not set separate limits for suspension blending
resins. During the comment period, industry provided additional resin
data regarding suspension blending resins. As described in section V.D
of this preamble, we have set limits for five types of resin, including
suspension blending. Therefore, a definition to distinguish suspension
blending resins from other resin types is necessary. The definition is
based on the information provided in comments. In the final rule,
suspension blending process means a process for producing polyvinyl
chloride resin that is similar to the suspension polymerization
process, but employs a rate of agitation that is significantly higher
than the highest range for non-blending suspension resins. The
suspension blending process uses a recipe that creates extremely small
resin particles, generally equal to or less than 100 microns in size,
with a glassy surface and very little porosity. The suspension blending
process concentrates the resins using a centrifuge that is specifically
designed to handle these small particles. Polyvinyl chloride resins
produced using the suspension blending process are referred to as
blending resins and are typically blended with dispersion resins.
    At proposal, we did not subcategorize process vents. For the final
rule, we are subcategorizing process vents into PVC-only and PVC-
combined vents for reasons discussed in section V.D of this preamble.
Therefore, it is necessary to distinguish between the two process vent
subcategories. In the final rule, PVC-only process vent means a process
vent that originates from a PVCPU and is not combined with a process
vent originating from another source category prior to being controlled
or emitted to the atmosphere. In the final rule, PVC-combined process
vent means a process vent that originates from a PVCPU and is combined
with one or more process vents originating from another source category
prior to being controlled or emitted to the atmosphere.
    At proposal, we did not have information on gasholders and did not
propose standards for them. Following proposal, industry provided
comment on control options and cost information for gasholders and we
have included requirements for gasholders in the final rule. Therefore
it was necessary to add a definition for gasholders to the final rule.
The definition is based on information provided in comments. In the
final rule, gasholder means a surge control vessel with a bell that is
floating in a vessel filled with water and is used to store gases from
the PVC production process prior to being recovered or sent to a
process vent control device. The bell rises and lowers as low-pressure
gases enter and leave the space beneath the bell and the water provides
a seal between the enclosed gas within the floating bell and the
ambient air.
    At proposal, we did not define maintenance wastewater, but instead,
required that all wastewater be subject to the same proposed
provisions. We received comments from industry contending that
quantifying a concentration to establish compliance for maintenance
wastewater would be extremely difficult if not impossible because
maintenance activities are highly variable. Industry also noted that
HAP are minimized in maintenance wastewater by requiring that
components meet applicable opening standards before the introduction of
water for cleaning. The final rule includes provisions that address
process and maintenance wastewater separately; therefore, we have added
definitions for maintenance wastewater and process wastewater to the
final rule. The definitions are based on those provided

in the HON, because the wastewater streams are similar and, in some
cases, they are co-located. In the final rule, maintenance wastewater
means wastewater generated by the draining of process fluid from
components in the PVCPU into an individual drain system prior to or
during maintenance activities. Maintenance wastewater can be generated
during planned and unplanned shutdowns and during periods not
associated with a shutdown. Examples of activities that can generate
maintenance wastewaters include descaling of heat exchanger tubing
bundles, hydroblasting PVCPU process components such as polymerization
reactors, vessels and heat exchangers, draining of low legs and high
point bleeds, draining of pumps into an individual drain system,
draining of portions of the PVCPU for repair and water used to wash out
process components or equipment after the process components or
equipment has already been opened to the atmosphere and has met the
requirements of 40 CFR 63.11955. In the final rule, process wastewater
means water that comes into direct contact with HAP or results from the
production or use of any raw material, intermediate product, finished
product, by-product or waste product containing HAP, but that has not
been discharged untreated as wastewater. Examples are product tank
drawdown or feed tank drawdown; water formed during a chemical reaction
or used as a reactant; water used to wash impurities from organic
products or reactants; water used to cool or quench organic vapor
streams through direct contact; water discarded from a control device;
and condensed steam from jet ejector systems pulling vacuum on vessels
containing organics. Gasholder seal water is not process wastewater
until it is removed from the gasholder.
    In the final rule, wastewater stream means a stream that contains
only wastewater as defined in this section.
    Also in the final rule, table 10 HAP means a HAP compound listed in
table 10 of final rule. Total non-vinyl chloride organic HAP means, for
the purposes of this subpart, the sum of the measured concentrations of
each table 10 compound as calculated according to the procedures
specified in 40 CFR 63.11960(e) and 40 CFR 63.11980(b).

J. Cost and Emission Impacts

    Comment: Three commenters expressed concern that costs for PRD are
greatly underestimated. One commenter estimated that retrofitting
existing PRD with release indicators will cost $5,000 per PRD. The
commenter stated that these costs include the actual measurement device
itself, installation labor, wiring back to the control room, input/
output cards in distributed control system (DCS) and initial
configuration (programming) of the DCS for alarms, logging, etc. The
commenter stated that with two facilities each containing over 100 PRD
the total cost would be over $1,000,000 to retrofit. Another commenter
also cited an estimate of $5,000 if a wireless pressure monitoring
device is used, or $10,000 per PRD if a more substantial flow
monitoring device is needed. The commenter estimated the cost for its
three facilities with 393 total PRD would range from $1,965,000 to
$3,930,000 to retrofit. A third commenter estimated a cost of $10,000
to retrofit each PRD, accounting for installation and integration into
the process control system. With approximately 200 PRD at a facility,
the commenter estimated a total cost of $2,000,000. One commenter also
noted that if the EPA is requesting pressure switches between the
rupture discs and the safety valves, this is ``relatively'' easy to
accomplish because it would require the instrument, communication
wiring, and a small amount of piping. This commenter also requested
that the EPA make it clearer whether flow indication or pressure
indication is required in the proposed rule. Additionally, one
commenter stated that multiple systems for release indication already
exist within PVC operations.
    One commenter expressed concern about bypass flow indicator costs.
The commenter stated that a conservative estimate to install bypass
flow indicators is similar to that for flow indication on PRD,
approximately $5,000 per open ended line. Considering there are
hundreds of such lines, the commenter indicated that installation cost
could exceed $1,000,000 per facility.
    Response: The EPA maintains that the capital cost estimate of
$188,900 and annual cost estimate of $26,900 per facility is
appropriate. Although commenters provided cost estimates for particular
facilities, costs provided in the comment letters were general in
nature, and the commenters did not provide documentation or detailed
cost analyses such that the provided estimates could be reviewed.
Therefore, we must estimate costs for all facilities using a consistent
methodology which is based on data collected by the EPA. We developed
our cost estimate for electronic PRD monitoring systems using the
Proposed Amended Rule 1173--Control of Volatile Organic Compound Leaks
and Releases from Components at Petroleum Facilities and Chemical
Plants, from the South Coast Air Quality Management District. Other
commenters have stated that most PVC plants ``typically have rupture
discs installed below relief valves that discharge to the atmosphere,
and monitor the space between the rupture disc and the PRD for leaks on
a routine basis using a local pressure indicator and log this
information for safety purposes.'' The EPA maintains that a facility
must use a monitor to indicate an emission release to the atmosphere;
the type of indicator is left to the facility.
    Comment: Several commenters took issue with the cost estimates
related to resin stripping. The commenters stated that current
technology will not allow facilities to meet the resin limits and
indicated that it will be necessary to develop new technology and the
associated costs will be much greater than the current EPA stripped
resin cost estimate. One commenter stated that millions of dollars will
be required to develop the technology and install equipment. Commenters
contended that improvements in PVC resin stripping beyond that which
can be achieved to meet new MACT floor HAP concentrations are not
feasible due to thermal degradation of PVC resins with elevated heat
histories (combination of higher temperatures and residence times). One
commenter added that steam is one of many components in the resin
stripping process, but it cannot be used as the sole or primary control
technique without seriously degrading the resin product. Commenters
indicated that some types and grades of resin are sensitive to heat
history such as that incurred by steam stripping and that color and
heat stability can be negatively impacted by excess heat history.
Several commenters disagreed with the EPA's conclusion that PVCPU would
only need to use additional steam in existing equipment to strip resin
to comply with the proposed vinyl chloride and total HAP emission
limits. Commenters also indicated that the effectiveness of certain
types of stripping technologies is not increased by the addition of
steam above energy balance requirements. Another commenter added that
PVC resins, some types and grades more than others, are sensitive to
heat such as that incurred by steam stripping. One commenter stated
that the EPA offered no substantiation for the claim that more steam in
existing equipment would provide for anything more than negligible
reductions in vinyl chloride and HAP levels in stripped resin. The
commenter added that two of the major

licensors of PVC resin stripping technology have said they would not
guarantee new equipment, let alone existing equipment, could meet the
proposed limit of 0.48 ppmw of vinyl chloride for all resins.
Commenters indicated that for some PVC grades, a significant column
retrofit or replacement would be necessary to meet more stringent resin
limits.
    Response: For the final rule, we revised the methodology used to
estimate cost impacts for stripped resin based on the comments and
additional cost data provided by commenters. For the proposed rule,
costs of affected sources meeting the proposed concentration standards
for stripped resins were estimated by calculating the amount of
additional steam required to strip vinyl chloride and total HAP to the
proposed concentration standards. Based on comments and information
provided by commenters, we agree that costing additional steam may not
be the appropriate control technique to meet the stripped resin limits.
For the final rule, we estimated costs of affected sources
demonstrating compliance with the final stripped resin concentration
standards by calculating the cost of installing a new resin stripper,
based on information provided by commenters. We did not include annual
costs other than the amortized capital investment since affected
sources must currently pay for the operation and maintenance of their
current resin strippers. Additionally, we have revised MACT floor
calculations, as discussed in section V.E.2 of this preamble. The
revised MACT floor and impacts analyses show that one facility will not
be able to meet the final limits. Based on information received during
the public comment period, we estimate the one facility not able to
meet the final limits will be required to install a new resin stripper
with a total capital cost of $10 million and a total incremental annual
cost of $944,000 per year.
    Comment: Several commenters expressed concern with the costs
imposed by wastewater compliance requirements. One commenter contended
that requiring monthly sampling for HAP in wastewater will impose undue
hardship on facilities when they are required to perform continuous
monitoring of stripper operating levels as well. This commenter
estimated an additional $65,000 per year from the monthly sampling.
Another commenter stated that due to the low wastewater vinyl chloride
limit, the cost for controls will be much higher. The commenter added
that simply adding steam will be insufficient and that it will be
necessary to replace the stripper at a cost of $3,400,000 with annual
operating costs of $636,000. One commenter recommended that the HAP
control requirements (testing, sampling, etc.) should be removed from
the wastewater rule since no emission benefit is achieved.
    Response: Similar to our decision for stripped resins in the final
rule, we have removed all requirements for continuous parametric
monitoring of wastewater strippers. The requirements to conduct
periodic sampling for vinyl chloride and total non-vinyl chloride
organic HAP are sufficient to assure compliance with the stripped resin
limits. We have also established a revised limit for total non-vinyl
chloride organic HAP from process wastewater. Monthly sampling and
analysis for total non-vinyl chloride organic HAP is necessary to
ensure that the limits are being met on a continuous basis. We have
also substantially reduced the burden on facilities by only requiring
re-analysis of untreated streams once per year to ensure that those
streams are below the process wastewater limits and that they do not
require treatment. These changes have significantly reduced the burden
of the final rule.

K. Economic Impacts

    Comment: Several commenters expressed concern with the economic
ramifications of the proposed rule to PVC producers and consumers. The
commenters stated that the EPA did not adequately quantify the effect
to the entire PVC supply chain when considering the rule and that as a
result many hardships and changes will occur. Commenters contended that
impacts will be cascaded down the supply chain and increase cost of
doing business. One commenter encouraged the agency to review and
carefully consider these impacts in light of the Obama Administration's
Executive Order 13563, Improving Regulation and Regulatory Review,
which calls for review and revision of regulations that stifle job
creation and economic growth.
    Commenters argued the PVC MACT will impact a company's
competitiveness in the global market, where overseas PVC producers are
not subject to such stringent regulations. One commenter expressed
concern with the impact on construction of new plants; the proposed PVC
rule will pose a significant deterrent to any company that considers
citing new or reconstructed PVC manufacturing in the United States
causing additional harm to the economy. Several commenters expressed
concern that if enacted without significant revision, the PVC rule will
result in the closure of several plants in the United States.
    One commenter representing the chlor-alkali industry provided an
example of how the PVC rule will impact related industries. The
commenter stated that as currently proposed compliance by United States
PVC manufacturing facilities with the MACT will cause a 4-percent-8-
percent reduction in demand in the domestic chlorine market. Based on
average industry pending patterns and labor-output ratios, in total,
between 3,300 and 6,600 jobs are at risk.
    Commenters expressed concern regarding the economic impacts to
several industries, including: the wall covering industry, the vinyl
flooring industry, resilient flooring operations, pipe applications and
the vinyl siding products industry.
    Several commenters contended that the PVC rule would result in loss
of performance characteristics and cost increases due to
discontinuation and substitution of a different quality or type of
resin for a previously formulated material, engineering changes, such
as retooling or the necessary investment in new or replacement
equipment due to the different types or qualities of resin and
different formulations, and loss of time as new formulations may take
years to develop and refine for their intended application. The
commenters contended that over 100 types and grades of PVC resins will
be affected, resulting in significant impact on how compounders,
converters and fabricators operate, potentially changing product
performance or raising costs. Other Two commenters stated that the net
cost to consumers in the United States and Canada for the substitution
of alternative materials for the PVC-based products that they currently
use would be almost $17.7 billion dollars per year, plus an additional
$5.6 billion in new investment to manufacture the incremental volume of
substitute material and an associated $2.8 billion per year in capital
recovery charges (details for numbers are in the document, The Economic
Benefits of Polyvinyl Chloride in the United States and Canada,
released by the American Chemistry Council and The Vinyl Institute in
2008). Several commenters expressed concern that imposing overly
stringent requirements on PVC resin manufacturers will significantly
increase imports from foreign sources and result in less domestic
competition.
    Response: The final rule contains several revisions that reduce the
annual cost of the final rules by more than 75 percent from proposal
($19.7 million per year at proposal to $4.1 million per

year for the final rules, for major and area sources combined). These
revisions are discussed in section VI of this preamble. For the reasons
described above, we have revised subcategories and the MACT floor
calculation for stripped resins resulting in revised limits for
stripped resins. These changes result in stripped resin limits that are
achievable by 15 out of 16 sources without installation of additional
controls. Based on information received during the public comment
period, the EPA estimates the one facility not able to meet the final
stripped resin limits for major sources will be required to install a
new resin stripper with a total capital cost of $10 million and an
incremental annual cost of $944,000 per year. As a result, the final
rule does not impose a significant burden on the source category as a
whole. The commenters also did not supply any data or analysis to
justify their assertions regarding potential plant closures, negative
employment impacts, reduction in demand for chlorine, negative effects
on the PVC supply chain, possible increases in imports or other
economic harm.
    Comment: One commenter expressed concern with the lack of
consideration given to small businesses. The commenter stated that the
EPA's Economic Impact Analysis identified only eight companies affected
by the proposed rule. The commenter added that because all eight of
these companies have more than 1,500 employees and annual revenues
above $2 billion, the EPA certified the proposed rule and declared no
significant economic impact on a substantial number of small entities.
As such, no regulatory flexibility analysis was prepared by the agency.
However, the commenter contended, the EPA did not host any ``SBREFA
panels'' prior to reaching this conclusion, preventing the small
business community from providing relevant input on the proposed rule's
impacts. The commenter stated that there will be higher costs due to
the PVC MACT which could be passed along the supply chain in the form
of higher prices to customers, many of whom may be small businesses and
less able to absorb regulation-induced price increases. The commenter
concluded that the EPA should amend its analysis to investigate the
secondary effect of the regulation on small businesses down the supply
chain.
    Response: The analysis of impacts on small entities called for by
the Regulatory Flexibility Act (RFA), as amended by the Small Business
Regulatory Enforcement Fairness Act (SBREFA), is to cover small
entities directly affected by a rule. The RFA does not require indirect
or secondary impacts to be included in a small entity analysis. This is
consistent with the EPA's interpretation of the RFA as amended by
SBREFA. Only rules that will have a direct significant adverse economic
impact on a substantial number of small entities that are subject to
the rule require an Initial Regulatory Flexibility Analysis or Final
Regulatory Flexibility Analysis (see 5 U.S.C. sections 603-605).

L. Affirmative Defense

    Comment: Several commenters opposed the EPA's affirmative defense
requirements. One commenter contended it is unlawful and arbitrary
because, although the EPA has eliminated its compliance exemption for
periods of startup, shutdown and malfunction, the agency's final rule
includes an ``affirmative defense to penalties that purports to bar
courts from imposing any penalties on sources that violate their
emission standards during a malfunction and satisfy certain agency
created conditions related to preventing malfunctions and controlling
malfunction emissions.'' This commenter contended that in this
proposal, the EPA acts outside of its delegated authority to limit
civil penalties available in citizen suits or its own enforcement
actions, and the proposal will impermissibly chill citizen
participation and the ability to win an effective, deterrent remedy in
CAA enforcement actions. The commenter added that the affirmative
defense would likely be used on a routine basis by polluters seeking to
avoid penalties, imposing a technical burden on citizens seeking civil
penalties against polluters.
    Another commenter opposed incorporating affirmative defense
penalties into regulations. The commenter stated that the EPA has
discretion to decide what cases to prosecute, to consider settlements
and to request civil penalties in a case-by-case manner, as long as it
acts consistent with the CAA to protect clean air as its top priority
and, thus, the commenter believes that promulgating this affirmative
defense will allow polluters to claim that any violation of the
standard is due to a malfunction in order to evade the requirements.
    Another commenter requested that if affirmative defense is
promulgated, the EPA specify the amount of compensatory damages should
apply to each malfunction, modify the rule so that affirmative defense
cannot be used by a specific facility or company more than once within
a set period of time, and require public reporting of malfunctions or
emissions exceedances.
    Response: The EPA included an affirmative defense in the final rule
in an attempt to balance a tension inherent in many types of air
regulation to ensure adequate compliance, while simultaneously
recognizing that despite the most diligent of efforts, emission limits
may be exceeded under circumstances beyond the control of the source.
The EPA must establish emission standards that ``limit the quantity,
rate, or concentration of emissions of air pollutants on a continuous
basis.'' 42 U.S.C. 7602(k) (defining ``emission limitation and emission
standard''). See generally Sierra Club v. EPA, 551 F.3d 1019, 1021
(D.C. Cir. 2008). Thus, the EPA is required to ensure that CAA section
112 emissions limitations are continuous. The affirmative defense for
malfunction events meets this requirement by ensuring that even where
there is a malfunction, the emission limitation is still enforceable
through injunctive relief. While ``continuous'' limitations, on the one
hand, are required, there is also caselaw indicating that in many
situations it is appropriate for the EPA to account for the practical
realities of technology. For example, in Essex Chemical v. Ruckelshaus,
486 F.2d 427, 433 (D.C. Cir. 1973), the District of Columbia Circuit
acknowledged that in setting standards under CAA section 111, ``variant
provisions,'' such as provisions allowing for upsets during startup,
shutdown and equipment malfunction ``appear necessary to preserve the
reasonableness of the standards as a whole and that the record does not
support the `never to be exceeded' standard currently in force.'' See
also, Portland Cement Association v. Ruckelshaus, 486 F.2d 375 (D.C.
Cir. 1973). Though intervening caselaw such as Sierra Club v. EPA and
the CAA 1977 amendments calls into question the relevance of these
cases today, they support the EPA's view that a system that
incorporates some level of flexibility is reasonable. The affirmative
defense simply provides for a defense to civil penalties for excess
emissions that are proven to be beyond the control of the source. By
incorporating an affirmative defense, the EPA has formalized its
approach to upset events. In a Clean Water Act setting, the Ninth
Circuit required this type of formalized approach when regulating
``upsets beyond the control of the permit holder.'' Marathon Oil Co. v.
EPA, 564 F.2d 1253, 1272-73 (9th Cir. 1977). But, see, Weyerhaeuser Co.
v. Costle, 590

F.2d 1011, 1057-58 (D.C. Cir. 1978) (holding that an informal approach
is adequate). The affirmative defense provisions give the EPA the
flexibility to both ensure that its emission limitations are
``continuous,'' as required by 42 U.S.C. 7602(k), and account for
unplanned upsets and, thus, support the reasonableness of the standard
as a whole. The EPA is not adopting commenters' suggestion with respect
to compensatory damages or limits on the frequency of use of the
affirmative defense. It is not clear that EPA has authority to require
the automatic imposition of compensatory damages and even if such
authority exists, the EPA does not think automatic imposition of
damages is appropriate. Ensuring that malfunctions do not recur can be
handled through imposition of appropriate injunctive relief. In
addition, the EPA's view is that it would not be appropriate to limit a
source's ability to take advantage of the affirmative defense to one
time over a specified period of time, such as 10 years, given that the
affirmative defense is only available when the source could not have
prevented the excess emissions. With respect to commenters' suggested
reporting requirements, the reporting requirements in the rule
promulgated here already require malfunction reporting and the
affirmative defense provisions require that parties choosing to assert
the affirmative defense meet additional malfunction reporting
requirements. Any such reports submitted to the EPA are publicly
available pursuant to CAA section 114.

M. Beyond-the-Floor Analyses

    At proposal, we determined that the control technologies that would
be needed to achieve the proposed MACT floor levels for process vents
are generally the most effective controls available for reducing vinyl
chloride, HCl, THC and CDD/CDF and we estimated the costs for those
technologies for facilities that did not meet the proposed limits for
process vents. Furthermore, at proposal, we did not identify any
beyond-the-floor options for process vents. For the final rule, as a
beyond-the-floor option for process vents (i.e., PVC-only and PVC-
combined process vents), we assessed the costs and emission reductions
for existing major source facilities to meet the new source limits for
both process vent subcategories by using enhanced vinyl chloride
recovery (via an upgraded refrigerated condenser). Based on the
resulting analysis of the cost effectiveness, we determined it is not
appropriate to go beyond-the-floor for either subcategory of process
vents at existing sources. This analysis is discussed in the
memorandum, Revised Beyond-the-Floor Analysis for the Polyvinyl
Chloride and Copolymers (PVC) Production Source Category.
    For stripped resin at existing and new major sources, we analyzed
the same beyond-the-floor option as at proposal, and determined it was
not appropriate to go beyond-the-floor for stripped resin at existing
and new major sources considering the cost and emission reductions of
this option.
    For equipment leaks, we analyzed a beyond-the-floor option at
existing sources of complying with 40 CFR part 63, subpart UU level 2,
instead of the MACT floor level of control, compliance with 40 CFR part
61, subpart V. Based on the results of the analysis, which are
presented in Tables 16 and 18 of this preamble, we determined that it
is appropriate that MACT for equipment leaks at existing and new major
sources require compliance with subpart UU level 2, considering the
cost and emission reductions of this option. The MACT floor level of
control for new sources, compliance with subpart UU level 2, was
identified as the most effective control of emissions from equipment
leaks. Therefore, no beyond-the-floor HAP emission reduction approaches
were identified for equipment leaks at new major sources. This analysis
is discussed in sections VI.A and VI.B of this preamble and in the
memorandum, Revised Beyond-the-Floor Analysis for the Polyvinyl
Chloride and Copolymers (PVC) Production Source Category.
    For heat exchange systems, we determined that the final leak action
level and monitoring interval are generally the most effective LDAR
program to control emissions from heat exchange systems. Therefore, no
beyond-the-floor options were identified for heat exchange systems at
existing or new major sources.
    At proposal and for the final rule, we determined it is appropriate
for storage vessels at existing and new major sources meeting specific
vapor pressure and storage capacity parameters specified in 40 CFR part
60, subpart Kb to comply with the control requirements of 40 CFR part
63, subpart WW as a beyond-the-floor control considering cost and
emission reductions. This analysis is discussed in sections VI.A and
VI.B of this preamble and in the memorandum, Revised Beyond-the-Floor
Analysis for the Polyvinyl Chloride and Copolymers (PVC) Production
Source Category.
    At proposal, we analyzed a beyond-the-floor option for wastewater
of treating streams with HAP concentration greater than 1,000 ppmw (of
40 CFR part 63, subpart G, Table 9 HAP), and annual average flow rates
greater than 10 liters per minute. In the final rule, we determined the
MACT floor level of control for wastewater to includes concentration
limits for total non-vinyl chloride organic HAP. Consequently, we
analyzed a different beyond-the-floor options for wastewater, requiring
all currently uncontrolled process wastewater (e.g., wastewater from
scrubbers and heat exchange systems) to be conveyed to, and treated by,
a wastewater stripping unit. Based on the results of this analysis, we
determined it is not appropriate to go beyond-the-floor for wastewater
at existing and new major sources considering the cost and emission
reductions of this option. This analysis is discussed in the
memorandum, Revised Beyond-the-Floor Analysis for the Polyvinyl
Chloride and Copolymers (PVC) Production Source Category.
    At proposal, we did not identify any beyond-the-floor options for
gasholders; however, we did solicit comments on control options for
gasholders. Based on the information provided in comments, for the
final rule, we analyzed a beyond-the-floor option of minimizing
fugitive emissions by requiring the use of floating objects on the
surface of the water seal at existing and new sources. Based on the
results of the analysis, which are presented in Tables 16 and 18 of
this preamble, we determined that it is appropriate to require
gasholders at existing and new major sources reduce their fugitive
emissions by using floating objects on the surface of the water seal as
a beyond-the-floor control, considering cost and emission reductions.
This analysis is discussed in the memorandum, Revised Beyond-the-Floor
Analysis for the Polyvinyl Chloride and Copolymers (PVC) Production
Source Category.

VI. Impacts of the Final PVC Rules

    The impacts presented in this section include the impacts for PVC
production facilities to comply with the final rules, and with the
requirements of other subparts referenced by the final rules.

A. What are the air impacts?

    We have estimated the potential emission reductions that are
expected to be realized through implementation of the final rules.
Table 18 of this preamble summarizes the emission reductions estimated
for existing major sources. The table shows the emission reductions for
each pollutant and emission point. Table 18 of this preamble also
summarizes the emission

reductions for the beyond-the-floor options selected for existing major
sources (i.e., control of equipment leaks, storage vessels and
gasholders). The major source analysis is documented in the memorandum,
Revised Costs and Emission Reductions for Major Sources in the
Polyvinyl Chloride and Copolymers (PVC) Production Source Category.
Table 19 of this preamble summarizes the emission reductions estimated
for existing area sources complying with GACT. The area source analysis
is documented in the memorandum, Generally Achievable Control
Technology (GACT) Analysis for Area Sources in the Polyvinyl Chloride
and Copolymers (PVC) Production Source Category. Both memoranda are
available in the docket. We do not project any new major or area
sources to be constructed in the 5 years following promulgation of the
final rules; no emission reductions were calculated for new sources.
The memoranda document emission reductions associated with model major
and area sources complying with the new source requirements.

      Table 18--Emission Reductions of the Final PVC and Copolymers Production Standards for Major Sources
----------------------------------------------------------------------------------------------------------------
                                                             Pollutant emission reductions (tpy)
                                            --------------------------------------------------------------------
               Emission point                   Vinyl
                                               chloride    Total HAP          CDD/CDF  (TEQ)             HCl
----------------------------------------------------------------------------------------------------------------
                                            Major sources MACT floor
----------------------------------------------------------------------------------------------------------------
Process vents \a\..........................        0.102         1.93  0.017 g/yr..................         21.4
Stripped resins............................         7.58         7.58  0...........................            0
Wastewater.................................            0            0  0...........................            0
Equipment leaks............................            0            0  0...........................            0
Storage vessels............................            0            0  0...........................            0
Other emission sources.....................            0            0  0...........................            0
Heat exchange systems......................          101          101  0...........................            0
----------------------------------------------------------------------------------------------------------------
                                         Major sources beyond the floor
----------------------------------------------------------------------------------------------------------------
Equipment leaks............................            0         85.0  0...........................            0
Storage vessels............................            0            0  0...........................            0
Other emission sources-gasholders..........         22.0         22.0  0...........................            0
                                            --------------------------------------------------------------------
    Major Source total.....................          130          217  0.017 g/yr..................         21.4
----------------------------------------------------------------------------------------------------------------
\a\ Emission reductions for process vents are stated as total organic HAP; this value does not include HCl or
  chlorine reductions.

Table 19--Emission Reductions of the Final PVC and Copolymers Production
                       Standards for Area Sources
------------------------------------------------------------------------
                                      Vinyl       Dioxin/
          Emission point             chloride    furan (g/    Total HAP
                                      (tpy)         yr)         (tpy)
------------------------------------------------------------------------
Process vents....................            0            0            0
Heat exchange systems............         15.1            0         15.1
Stripped resins..................            0            0            0
Wastewater.......................            0            0            0
Equipment leaks..................            0            0         9.29
Other emission sources...........            0            0            0
------------------------------------------------------------------------

    We estimated emission reductions of the final rule for each
emission point. For all emission points, we first calculated emissions
at the current level of control for each facility (referred to as the
baseline level of control), and at the MACT level of control selected
for major sources and the GACT level of control selected for area
sources. We calculated emission reductions as the difference between
the final level and baseline.
Major Sources
    For process vents at major sources, we calculated baseline
emissions from the measured HAP concentrations at the outlet of the
control devices, and HAP emissions using the final emission limits, in
combination with the vent stream flow rates measured during emission
tests.
    For stripped resins at major sources, we calculated emissions
assuming that all the HAP remaining in the resin would eventually be
emitted from processes downstream of the resin stripper. This
assumption results in a calculation of the potential emissions at the
baseline stripped resin concentration levels, and final MACT
concentration levels. Emissions were calculated from the HAP
concentration in the stripped resin, and the resin production rate.
    For wastewater at major sources, we estimated the emissions from
the HAP concentration in the uncontrolled wastewater streams, the
maintenance wastewater streams, and in the controlled wastewater
streams, and the wastewater flow rates or generation rates.
    For equipment leaks at major sources, we estimated emissions for
the baseline LDAR program in use at each facility, and the final
equipment leaks requirements using model equipment counts, average
emission factors for leaking equipment and control efficiencies for
LDAR programs developed as part of the technology review required by
section 112(d)(6) of the CAA (see section V.H of this preamble for
additional detail). Model equipment counts were used because actual
equipment counts were not

collected as part of our August 21, 2009, CAA section 114 survey and
testing request sent to the PVC industry. The survey requested
information only on regulatory LDAR programs currently in place at each
facility, and the costs for the facility to conduct the LDAR program.
    For other emission sources, we estimated baseline emissions from
gasholders using information provided by industry during the comment
period. We estimated the emission reductions associated with installing
floating objects on gasholder water seals to reduce emissions of vinyl
chloride from those seals, as a beyond the floor option, based on
additional information provided by the PVC industry after the comment
period. We calculated emissions from reactor openings from information
provided in responses to our August 21, 2009, CAA section 114 survey
and testing request provided by affected sources.
    We calculated emissions from heat exchange systems based on
emissions information provided in the CAA section 114 survey responses
provided by affected sources. Emission reductions from heat exchange
systems were calculated assuming that, once the LDAR program was in
effect, emissions would be eliminated due to the low leak action level
that is being finalized.
Area Sources
    For process vents, we calculated emissions from the concentration
of HAP in the vent stream and the vent gas flow rates measured during
emission tests. For process vents in the PVC-only subcategory, we
calculated baseline emissions for the one area source in the
subcategory from the measured HAP concentrations at the outlet of the
control device. We did not select an option more stringent than the
current emission level; therefore, there were no emission reductions
calculated. For process vents in the PVC-combined subcategory, we
calculated baseline emissions for the one area source in the
subcategory from the measured HAP concentrations at the outlet of the
control. Since the existing PVC-combined area source currently meets
the GACT standards, we did not calculate a reduction of HAP emissions
associated with meeting the GACT emission limits.
    For stripped resins, emissions were calculated from the HAP
concentration in the stripped resin, and the resin production rate. For
the one existing area source in the suspension subcategory, we
calculated emissions assuming that all the HAP remaining in the resin
would eventually be emitted from processes downstream of the resin
stripper. This assumption results in a calculation of the potential
emissions at the stripped resin concentration levels the affected is
currently achieving. Since the existing PVC area source in the
suspension resin subcategory currently meets the GACT standard, no
emission reductions were calculated. For the one existing area source
in the bulk resins subcategory, we estimated emissions downstream of
the resin stripper using emission rates submitted by the facility since
resin produced by the bulk process does not go through downstream
drying processes since the resin is in solid form after the
polymerization process.
    For wastewater at existing area sources, we estimated the emissions
from the HAP concentration in the uncontrolled wastewater streams, the
maintenance wastewater streams, and in the controlled wastewater
streams, and the wastewater flow rates or generation rates.
    For equipment leaks at existing area sources, we estimated
emissions for the LDAR program in use at both area sources and
emissions associated with complying with the GACT option. Emissions
were calculated using a combination of facility provided and model
equipment counts, average emission factors for leaking equipment and
control efficiencies for LDAR programs developed as part of the
technology review required by section 112(d)(6) of the CAA (see section
V.H of this preamble for additional detail). Model equipment counts
were used for equipment types for which counts were not provided by the
affected sources. The CAA section 114 survey requested information only
on regulatory LDAR programs currently in place at each facility, and
the costs for the facility to conduct the LDAR program; however, one
facility provided some, but not all equipment counts for which
emissions were estimated.
    For other emission sources, we calculated emissions from reactor
openings from information provided in CAA section 114 survey responses
provided by affected sources. The existing PVC area sources currently
do not operate gasholders; therefore no emissions from gasholders were
calculated for area sources.
    We calculated emissions from heat exchange systems based on
emissions information provided in the CAA section 114 survey responses
provided by affected sources. Emission reductions from heat exchange
systems were calculated assuming that, once the LDAR program was in
effect, emissions would be eliminated due to the low leak action level
that is being finalized.

B. What are the cost impacts?

    We have estimated compliance costs for all existing sources to meet
the sampling and testing requirements, add the necessary controls,
monitoring devices, recordkeeping and reporting procedures to comply
with the final rules. Based on this analysis, we anticipate an overall
total initial investment of $17.6 million for major sources and
$486,000 for area sources. We anticipate an associated total annual
cost of $3.94 million for major sources and $167,000 for area sources
(using a discount rate of 7 percent), in 2010 dollars, as shown in
Table 20 and Table 21 of this preamble. We do not anticipate the
construction of any new PVCPU in the next 5 years and, therefore, there
are no new source cost impacts. Estimated impacts of the new area
source requirements for a model facility are presented in the
memoranda, Costs and Emission Reductions of the MACT Floor Level of
Control for the Promulgated Polyvinyl Chloride and Copolymers (PVC)
Production Source Category and Cost and Emission Reductions of the Area
Source Level of Control for the Promulgated Polyvinyl Chloride and
Copolymers (PVC) Production Source Category, which are in the PVC
docket.

    Table 20--Cost Impacts of the Final PVC and Copolymers Production
                  Standards for Existing Major Sources
------------------------------------------------------------------------
                                           Total initial   Total annual
             Emission point               cost  (million  cost  (million
                                            2010$) \a\     2010$/yr) \b\
------------------------------------------------------------------------
                        Major sources MACT floor
------------------------------------------------------------------------
Process vents...........................            3.38            1.72
Stripped resins.........................            10.1            1.13
Wastewater..............................           0.075           0.165
Equipment leaks.........................            2.87           0.469
Storage vessels.........................          0.0165          0.0233
Other emission sources..................          0.0165          0.0233
Heat exchange systems...................          0.0466           0.152
------------------------------------------------------------------------
                     Major sources beyond the floor
------------------------------------------------------------------------
Equipment leaks.........................            1.02           0.238