[Federal Register: February 16, 2006 (Volume 71, Number 32)]
[Rules and Regulations]
[Page 8341-8387]
From the Federal Register Online via GPO Access [wais.access.gpo.gov]
[DOCID:fr16fe06-10]
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Part II
Environmental Protection Agency
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40 CFR Part 63
National Emission Standards for Hazardous Air Pollutants: Plywood and
Composite Wood Products; List of Hazardous Air Pollutants, Lesser
Quantity Designations, Source Category List; Final Rule
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ENVIRONMENTAL PROTECTION AGENCY
40 CFR Part 63
[OAR-2003-0048; FRL-8028-9]
RIN 2060-AN05
National Emission Standards for Hazardous Air Pollutants: Plywood
and Composite Wood Products; List of Hazardous Air Pollutants, Lesser
Quantity Designations, Source Category List
AGENCY: Environmental Protection Agency (EPA).
ACTION: Final rule, amendments; notice of final action on
reconsideration.
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SUMMARY: On July 30, 2004, EPA promulgated national emission standards
for hazardous air pollutants (NESHAP) for the plywood and composite
wood products (PCWP) source category. The Administrator subsequently
received a petition for reconsideration of certain provisions in the
final rule. In addition, following promulgation, stakeholders expressed
concern with some of the final rule requirements including definitions,
the emissions testing procedures required for facilities demonstrating
eligibility for the low-risk subcategory, stack height calculations to
be used in low-risk subcategory eligibility demonstrations, and
permitting and timing issues associated with the low-risk subcategory
eligibility demonstrations. In two separate Federal Register notices
published on July 29, 2005, we announced our reconsideration of certain
aspects of the final rule, and we proposed amendments to the final
rule. In the notice of reconsideration, we requested public comment on
the approach used to establish and delist a low-risk subcategory of
PCWP affected sources, as outlined in the final rule, and on an issue
related to the final rule's startup, shutdown, and malfunction (SSM)
provisions. In the proposed amendments notice, we proposed simplifying
the requirements for the low-risk demonstrations (LRD) and allowing
additional time for facilities to submit them. We also requested
comment on whether to extend the MACT compliance date. We also
clarified some common applicability questions. In this action, we are
promulgating amendments to the PCWP NESHAP and providing our
conclusions following the reconsideration process.
DATES: February 16, 2006. The incorporation by reference of one
publication listed in this final action is approved by the Director of
the Office of the Federal Register as of February 16, 2006.
ADDRESSES: Docket. The EPA has established a docket for this action
under Docket ID No. OAR-2003-0048 and Legacy Docket ID No. A-98-44. All
documents in the docket are listed on the http://www.regulations.gov Web site.
Although listed in the index, some information is not publicly
available, e.g., confidential business information (CBI) or other
information whose disclosure is restricted by statute. Certain other
material, such as copyrighted material, is not placed on the Internet
and will be publicly available only in hard copy form. Publicly
available docket materials are available either electronically through
http://www.regulations.gov or in hard copy at the Air and Radiation Docket and
Information Center, EPA/DC, EPA West, Room B102, 1301 Constitution
Ave., NW, Washington, DC. The Public Reading Room is open from 8:30
a.m. to 4:30 p.m., Monday through Friday, excluding legal holidays. The
telephone number for the Public Reading Room is (202) 566-1744, and the
telephone number for the Air and Radiation Docket and Information
Center is (202) 566-1742.
FOR FURTHER INFORMATION CONTACT: For information concerning
applicability and rule determinations, contact your State or local
representative or appropriate EPA Regional Office representative. For
information concerning rule development, contact Ms. Mary Tom Kissell,
Sector Policies and Program Division, (Mailcode: C439-03), EPA,
Research Triangle Park, NC 27711; telephone number: (919) 541-4516; fax
number: (919) 541-0246; e-mail address: kissell.mary@epa.gov.
SUPPLEMENTARY INFORMATION:
Regulated Entities
Categories and entities potentially affected by today's action
include:
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SIC code NAICS Examples of
Category a code b regulated entities
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Industry.................... 2421 321999 Sawmills with lumber
kilns.
2435 321211 Hardwood plywood and
veneer plants.
2436 321212 Softwood plywood and
veneer plants.
2493 321219 Reconstituted wood
products plants
(particleboard,
medium density
fiberboard,
hardboard,
fiberboard, and
oriented
strandboard
plants).
2439 321213 Structural wood
members, not
elsewhere
classified
(engineered wood
products plants).
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a Standard Industrial Classification.
b North American Industrial Classification System.
This table is not intended to be exhaustive, but rather provides a
guide for readers regarding entities likely to be affected by today's
action. To determine whether your facility is affected by today's
action, you should examine the applicability criteria in Sec. 63.2231
of the final rule. If you have questions regarding the applicability of
today's action to a particular entity, consult Ms. Mary Tom Kissell
listed in the preceding FOR FURTHER INFORMATION CONTACT section.
Worldwide Web (WWW)
In addition to being available in the docket, an electronic copy of
today's action also will be available on the Worldwide Web (WWW)
through EPA's Technology Transfer Network (TTN). Following the
Administrator's signature, a copy of this action will be posted on the
TTN's policy and guidance page for newly promulgated rules at http://www.epa.gov/ttn/oarpg.
The TTN provides information and technology
exchange in various areas of air pollution control.
Judicial Review
Under section 307(b)(1) of the CAA, judicial review of the final
rule amendments to the NESHAP is available by filing a petition for
review in the U.S. Court of Appeals for the District of Columbia
Circuit by April 17, 2006. Under section 307(d)(7)(B) of the CAA, only
those objections that were raised with reasonable specificity during
the period for public comment may be raised during judicial review.
Under section 307(b)(2) of the CAA, the requirements that are the
subject of the
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final rule amendments may not be challenged later in civil or criminal
proceedings brought by EPA to enforce the requirements.
Outline
The information presented in this preamble is organized as follows:
I. Background
II. Comments and Responses on Low-risk Option
A. Legal Basis
B. Background Pollution and Co-located Emission Sources
C. Ecological Risk
D. The Dose-Response Value Used for Formaldehyde
E. Appendix B to 40 CFR Part 63 Subpart DDDD Requirements
F. Selection of Process Units and Emissions Determination
Procedures in Table 2A to Appendix B to 40 CFR Part 63 Subpart DDDD
G. Emission Testing Requirements in Appendix B to 40 CFR Part 63
Subpart DDDD
H. Compliance Date for Existing Sources
I. Low-Risk Demonstration Submittal Dates for Existing Sources
J. Compliance Date for Affected Sources Previously Qualifying
For the Low-Risk Subcategory
K. Low-Risk Demonstration Submittal Dates for New Sources
L. Legal Issues With Title V Implementation Mechanism
M. Timing of Title V Permit Revisions
N. Permit Conditions
O. Costs and Benefits of Establishing a Low-Risk Subcategory
III. Responses to Comments on the Proposed Amendments and
Clarifications for Subpart DDDD
A. Definitions
B. Applicability of the PCWP Rule to Lumber Kilns Drying Utility
Poles
C. Capture Efficiency Determination
D. Incorporation by Reference of NCASI Method ISS/FP-A105.01
IV. Responses to Comments on SSM Issues
V. Statutory and Executive Order Reviews
A. Executive Order 12866: Regulatory Planning and Review
B. Paperwork Reduction Act
C. Regulatory Flexibility Act
D. Unfunded Mandates Reform Act
E. Executive Order 13132: Federalism
F. Executive Order 13175: Consultation and Coordination With
Indian Tribal Governments
G. Executive Order 13045: Protection of Children From
Environmental Health and Safety Risks
H. Executive Order 13211: Actions That Significantly Affect
Energy Supply, Distribution, or Use
I. National Technology Transfer and Advancement Act
J. Congressional Review Act
I. Background
We proposed NESHAP for the PCWP source category on January 9, 2003
(68 FR 1276). The preamble for the proposed rule requested comment on
how and whether we should incorporate risk-based approaches into the
final rule to avoid imposition of regulatory controls on facilities
that pose little risk to public health and the environment. Fifty-seven
interested parties submitted comments on the proposed rule during the
comment period. The final rule (subpart DDDD in 40 CFR part 63) was
published on July 30, 2004 (69 FR 45944) after consideration of these
comments. We adopted a risk-based approach in the final rule by
establishing and delisting a low-risk subcategory of PCWP affected
sources based on our authority under section 112(c)(1) and (9) of the
Clean Air Act (CAA). Under this approach, PCWP affected sources may
submit for EPA approval proposed demonstrations that they meet certain
risk-based criteria and, therefore, are eligible to join the low-risk
subcategory and avoid applicability of the PCWP NESHAP. The methodology
and criteria for PCWP affected sources to use in demonstrating that
they are part of the delisted low-risk subcategory were promulgated in
appendix B to subpart DDDD of 40 CFR part 63. Sources whose LRD EPA
approves then must seek permit revisions under title V of the CAA that
incorporate their low-risk parameters as enforceable terms and
conditions in order to ensure they remain low-risk and remain exempt
from otherwise applicable PCWP NESHAP requirements.
Following promulgation of the final PCWP rule, the Administrator
received a petition for reconsideration filed by the Natural Resources
Defense Council (NRDC) and Environmental Integrity Project (EIP)
pursuant to section 307(d)(7)(B) of the CAA.\1\ The petition requested
reconsideration of nine aspects of the final rule: (1) Risk assessment
methodology, (2) background pollution and co-located emission sources,
(3) dose-response value used for formaldehyde, (4) costs and benefits
of the low-risk subcategory, (5) ecological risk, (6) legal basis for
the risk-based approach, (7) maximum achievable control technology
(MACT) compliance date for affected sources previously qualifying for
the low-risk subcategory, (8) SSM provisions, and (9) title V
implementation mechanism for the risk-based approach. The petitioners
stated that reconsideration of the above issues is appropriate because
they claimed that the issues could not have been practicably raised
during the public comment period. The petition for reconsideration also
requested a stay of the effectiveness of the risk-based provisions.
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\1\ In addition to the petition for reconsideration, four
petitions for judicial review of the final PCWP rule were filed with
the U.S. Court of Appeals for the District of Columbia by NRDC and
Sierra Club (No. 04-1323, D.C. Cir.), EIP (No. 04-1235, D.C. Cir.),
Louisiana-Pacific Corporation (No. 04-1328, D.C. Cir.), and Norbord
Incorporated (No. 04-1329, D.C. Cir.). The four cases have been
consolidated. In addition, the following parties have filed as
interveners: American Forest and Paper Association (AF&PA), Hood
Industries, Scotch Plywood, Coastal Lumber Company, Composite Panel
Association, APA-The Engineered Wood Association, American Furniture
Manufacturers Association, NRDC, Sierra Club, and EIP. Finally, the
Formaldehyde Council, Inc. and the State and Territorial Air
Pollution Program Administrators and Association of Local Air
Pollution Control Officials (STAPPA/ALAPCO) are participating in the
litigation as amicus curiae.
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In a letter dated December 6, 2004, EPA granted NRDC's and EIP's
petition for reconsideration and declined the petitioners' request that
we take action to stay the effectiveness of the risk-based provisions.
On July 29, 2005 (70 FR 44012), we published a notice of
reconsideration to initiate rulemaking by requesting comments on the
issues in the petition for reconsideration, including the full content
of appendix B to subpart DDDD.
In a separate notice published on July 29, 2005 (70 FR 44012), we
proposed amendments to subpart DDDD and both of the appendices to
subpart DDDD. We proposed amendments to appendix B to subpart DDDD to
reduce the number of emissions tests required while ensuring that
emissions from all PCWP process units at the relevant source are
considered when demonstrating eligibility for the low-risk subcategory.
For emission points that would still require emission tests, we
proposed that the emissions tests may be conducted after the LRD is
submitted. We also proposed that physical changes necessary to achieve
low-risk status may be completed after the LRD is submitted. We
proposed to alter the way the stack height is calculated for a look-up
table analysis and to clarify some timing issues related to LRD,
including the deadline for submitting LRD. We also requested comment on
whether the MACT compliance date should be extended for sources
submitting LRD or for all sources. Furthermore, we proposed to amend
subpart A to 40 CFR part 63, subpart DDDD of 40 CFR part 63, and
appendix B to subpart DDDD to allow use of a new test method developed
by the National Council of the Paper Industry for Air and Stream
Improvement (NCASI) for measuring hazardous air pollutants (HAP).
For 40 CFR part 63, subpart DDDD, we proposed several changes to
ensure that the rule is implemented as intended: (1) Amend the sampling
location for coupled control devices, (2) amend language to clarify
rule
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applicability during unscheduled startups and shutdowns, (3) add
language to clarify rule applicability for affected sources with no
process units subject to compliance options or work practice
requirements, and (4) amend selected definitions. A minor numbering
error was proposed to be corrected in appendix A to 40 CFR part 63,
subpart DDDD. We also clarified some common applicability questions,
and we requested comments on whether to extend the deadline for
compliance with the rule's requirements for all subject sources.
We received public comments from nine stakeholders on the
reconsideration issues during the comment period. Although some
commenters on the 2005 reconsideration referred to previous comments
they submitted following the 2003 proposal, we have not included the
previous comments in the summary presented here unless they are
directly relevant to the reconsideration. However, the previous
comments are included in the docket for this final rulemaking or the
background information document (BID). Our responses to comments today
are intended to respond to the comments specifically submitted on our
proposed reconsideration notice and to any relevant incorporated
comments. We received public comments from 12 stakeholders on the
proposed amendments during the comment period. We received supporting
comments only (or no comments) on a number of the proposed amendments,
including the proposed amendment to the: (1) Sampling location for
coupled control devices; (2) definitions of ``molded particleboard,''
``plywood and composite wood products manufacturing facility,'' and
``plywood''; (3) requirements for affected sources with no process
units subject to the compliance options or work practice requirements;
(4) numbering of paragraphs referenced in 40 CFR 63.2269; (5) test
methods for benzene; (6) criteria for assuming zero for Method 29 non-
detect measurements; and (7) numbering of appendix A to 40 CFR part 63,
subpart DDDD. We have promulgated these amendments as proposed based on
the rationale provided in the proposed rule (70 FR 44012, July 29,
2005), and no further discussion of these amendments is presented here.
We are also promulgating a revised compliance deadline for sources
subject to the rule, which is one year later than the date originally
promulgated. The new compliance deadline is October 1, 2008. Our
rationale for this revision is contained in our responses below.
II. Comments and Responses on Low-risk Option
A. Legal Basis
Comment: Several commenters stated that there are numerous ways in
which the risk-based exemptions contravene the language, structure, and
history of the 1990 CAA amendments and EPA's past policies. The
commenters noted that technology-based standards should precede risk-
based standards, that creating a subcategory based on risk is illegal,
that delaying the compliance date to allow the risk-based standards is
contrary to the CAA, that not setting emission standards is generally
not authorized, that considering sources in the low-risk subcategory
when establishing MACT floors is not allowed by the CAA, and that the
CAA does not authorize EPA to delist subcategories (versus categories)
of sources of carcinogenic emissions.
Other commenters stated there is ample legal basis for establishing
and delisting the low-risk PCWP subcategory and supported retaining the
low-risk option.
Response: After considering the 2003 proposed PCWP NESHAP and the
public comments submitted thereon, the 2004 final PCWP NESHAP, the
petition for reconsideration of the final PCWP NESHAP, the 2005 notice
of final PCWP NESHAP reconsideration and the comments submitted in
response to that notice, EPA stands by the legal rationale for the PCWP
low-risk approach explained in the 2004 final PCWP NESHAP (69 FR 45983-
45991, July 30, 2004) and incorporates that rationale by reference.
Regarding the comments on the proposed reconsideration that raised
new points or elaborated on points previously made, the explanation for
why risk may be an appropriate criterion for distinguishing between
sources in establishing source categories and subcategories has been
clearly set forth in the general policy rationale for the final PCWP
NESHAP and today's final action on reconsideration. CAA section
112(c)(9) shows that Congress intended that EPA be able, either in
advance of or following the promulgation of emission standards under
section 112, to remove source categories and subcategories from
regulation under section 112 ``whenever'' relevant risk-based findings
are made.
We disagree that the risk-based approach causes a delay in the
compliance date for MACT in contravention of section 112(d)(1) and
112(i). This is because the PCWP sources that remain in the MACT
category must meet emission standards by the promulgated MACT deadline,
and any sources that wish to join the low-risk subcategory and avoid
MACT at the compliance deadline must, on that date, either comply with
MACT or have been approved as a member of the low-risk subcategory.
While we have in today's final rule revised the MACT compliance
deadline to fall one year later than was originally promulgated, this
revision is not a result of the mere inclusion of the action we have
taken under section 112(c)(9). Rather, it is a result of the
significance of the changes we have made to the PCWP NESHAP overall, as
well as changed expectations about the scope of MACT-subject and would-
be low-risk sources who will need to obtain, install, and certify
emissions controls. It is also true that a source that is low-risk and
exempt from MACT at the compliance date may later undergo changes that
subject it to MACT for the first time, and that the PCWP rule in some
cases allows such a source to comply with MACT 3 years after it has
lost its low-risk status. This is consistent, however, with how we
treat area sources that change status to major sources and thereby join
a MACT-regulated category for the first time.
We also disagree that once EPA lists a category or subcategory, it
is absolutely required by section 112(c)(2) and 112(d)(1) to set
emission standards for that category or subcategory. Section 112(c)(9)
itself depends upon the identification of a ``category'' or
``subcategory'' as identifying the set of major sources that may be
deleted from the list of sources to be regulated, and indeed by its
terms assumes that the category or subcategory may be ``on the list''
(and possibly already regulated) before EPA determines that the risk-
based criteria to justify its removal have been met.
As we previously explained in the 2004 final PCWP NESHAP, the
approach we have taken for the low-risk PCWP subcategory is not the
source-by-source granting of risk-based exemptions rejected by Congress
in the 1990 CAA amendments. That approach would have allowed any
source, in any source category, to seek an exemption from section 112
standards, without demonstrating that it qualified under previously
established criteria to join an already existent delisted subcategory,
and without subsequent compliance responsibilities such as having to
incorporate its parameters reflecting low-risk eligibility into
federally enforceable permit terms and
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conditions. The PCWP approach, instead, operates more like the
applicability determination process that a source uses to discover
which set of multiple sets of applicable requirements under the CAA it
must comply with. If a PCWP source is not low-risk, it must meet MACT;
but if it meets the low-risk criteria, it must still meet specific,
enforceable requirements that can be enforced through the title V
permit to the same extent as otherwise applicable MACT standards. Our
approach is not the same as the rejected ``de minimis'' exemption since
sources must specifically show that they meet the statutory criteria of
section 112(c)(9) that define the low-risk PCWP source category,
criteria that are explicitly enumerated in the statutory language
itself, rather than based on a legal doctrine allowing exemptions from
statutory requirements notwithstanding the absence of express statutory
language for such exemption.
We are surprised by the commenter's assertion that our MACT floors
for non-low-risk PCWP sources may not be based, in part, on emissions
limitation achieved by sources that subsequently show they are eligible
for inclusion in the low-risk PCWP subcategory. When we develop MACT
standards, we necessarily start at a step where we do not already know
what the scope of the final standards' requirements will ultimately be.
In identifying the MACT floors for new and existing sources under
section 112(d)(2) and 112(d)(3), it is simply not possible to know with
certainty exactly which sources will have to meet MACT requirements. In
fact, it is always possible that any major source will change its
emissions or operations prior to the compliance date such that it is no
longer major and, therefore, not subject to the final standards. In the
case of PCWP, our approach presumes that nearly all sources are in the
MACT category at the outset and that sources may join the non-MACT
subcategory over time, but it would be impossible at the MACT floor
determination stage to estimate the ultimate population of low-risk
sources, just as it is impossible to estimate the number of major
sources that may become ``area'' sources before the MACT compliance
dates. In both cases, it would not be administratively feasible--nor is
it legally required--to adjust the MACT floor determination over time
as the MACT category population changes. There is no indication in the
CAA that such an approach, especially to the extent it excluded better-
performing sources from floor determinations and thereby weakened
technology-based standards, would be consistent with Congress's overall
purpose in basing section 112(d) standards on the emissions levels
achieved in practice by the best-performing sources.
Regarding the issue of whether EPA may delist only ``categories''
of sources that emit carcinogens, but not ``subcategories,'' EPA agrees
with the commenters that suggest there is functionally no difference
between the two terms, and that it is unnecessary to resolve the debate
over whether Congress committed a ``scrivener's error'' raised by other
commenters. In section 112(c), Congress provides EPA with broad
discretion in not only defining the criteria to be used to identify
individual categories and subcategories, but in deciding when one group
of sources might constitute a ``category'' versus a ``subcategory,''
there is literally no statutory definition of either term, and the use
of one over the other to define a group of sources is merely a semantic
distinction with no legal difference.
Regarding the commenter's objections to EPA's discussion regarding
congressional intent related to our authority to establish and delist
source categories and subcategories, we conclude that it is not
necessary, or even possible, to resolve the debate over what Congress
may or may not have silently intended, given the clear statutory
language in section 112(c)(1) and 112(c)(9). The plain language of
section 112(c)(1) explicitly states that nothing in that subsection ``*
* * limits the Administrator's authority to establish subcategories
under this section, as appropriate[,] * * *'' and given that Congress
created express authority to delist categories and subcategories under
section 112(c)(9) when the specified risk-based criteria are satisfied,
it is clearly appropriate for EPA to establish categories and
subcategories in a way that best enables the use of the authority
provided by section 112(c)(9) when the agency identifies source groups
that demonstrate they present no risks above the enumerated criteria.
Any other interpretation of the statutory language would unnecessarily
restrict the broad discretion that the CAA provides for this purpose.
We, therefore, agree with the commenters who stated that section 112,
especially when taken as a whole, provides ample authority for EPA's
risk-based approach in the 2004 final PCWP NESHAP.
Comment: Two commenters stated that section 112(d) of the CAA
clearly establishes a two-step process for addressing HAP emissions
through the MACT and residual risk provisions and that the risk-based
exemptions contained in the PCWP MACT are contrary to the CAA.
One commenter stated that risk-based exemptions are contrary to the
concept of the ``level-playing field'' that should result from the
proper implementation of technology-based MACT standards. The commenter
also noted that the National Air Toxics Assessment (NATA) information
shows the need for a nationwide technology-based approach and indicates
that HAP exposure is very high throughout the entire country in both
densely populated urban areas and remote rural locations.
Response: We disagree that inclusion of a low-risk subcategory in
the final PCWP rule is contrary to the 1990 CAA Amendments. The PCWP
MACT are technology-based standards developed using the procedures
dictated by section 112 of the CAA. The only difference between the
final PCWP rule and other MACT rules is that we used our discretion
under CAA section 112(c)(1) and 112(c)(9) to subcategorize and delist
low-risk affected sources, in addition to fulfilling our duties under
CAA section 112(d) to set MACT. It is clear from the statutory language
that, once EPA has listed a source category under section 112(c)(1), it
is then faced with the decision whether to regulate the source category
under section 112(d) or to delist it under section 112(c)(9). In light
of the authority provided by section 112(c)(9), it is unreasonable to
assert that once a category is listed it must in all cases be regulated
under section 112(d)(1), since the result of a delisting under section
112(c)(9) is that the source category is exempt from section 112
regulation. Moreover, nothing in the statutory language suggests that
this authority to implement section 112(c)(9) is limited by what effect
such action may have on competition within a specific industry. Rather,
section 112(c)(9) of the CAA requires that categories or subcategories
meet specific risk criteria in order to be delisted, and to determine
this, risk analyses may be used. We disagree with the commenter that we
must wait for implementation of CAA section 112(f) before utilizing
risk analysis in this manner, since nothing in section 112(c)(9)
suggests that its authority may not be used until after application of
technology-based standards under section 112(d). The 2004 final PCWP
NESHAP are particularly well-suited for a risk-based option because of
the specific HAP that are emitted by PCWP sources. For many affected
sources, the HAP are emitted in amounts that pose little risk to the
surrounding population. However, the cost of controlling these HAP is
high
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and may not be justified by environmental benefits for these low-risk
affected sources. Only those PCWP affected sources that demonstrate
that they are low-risk are eligible for inclusion in the delisted low-
risk subcategory. The criteria included in the 2004 final PCWP NESHAP,
as amended by today's final rulemaking, defining the delisted low-risk
subcategory are based on sufficient information to develop health-
protective estimates of risk and will protect human health and the
environment.
We agree that one of the primary goals of developing a uniform
national air toxics program under CAA section 112 of the 1990 CAA
amendments is to establish a ``level playing field,'' where
appropriate. We do not agree, however, that this goal limits our
broader authority under section 112(c)(1) and (9), and we do not feel
that defining a low-risk subcategory in the PCWP NESHAP does anything
to remove the level playing field for PCWP facilities. The PCWP NESHAP
and its criteria for demonstrating eligibility for the delisted low-
risk subcategory apply uniformly to all PCWP facilities across the
nation. The PCWP NESHAP establishes a baseline level of emission
reduction or a baseline level of risk (for the low-risk subcategory).
All PCWP affected sources are subject to these same baseline levels,
and all facilities have the same opportunity to demonstrate that they
are part of the delisted low-risk subcategory. Therefore, concerns
regarding facilities moving to areas of the country with air toxics
programs that are less-stringent than today's PCWP NESHAP should be
alleviated.
Although NATA may show measurable concentrations of toxic air
pollution across the country, these data do not suggest that PCWP
facilities that do not contribute to the high exposures and risk should
be included in MACT regulations, notwithstanding our authority under
CAA section 112(c)(9). Our decisions regarding whether a source has
demonstrated its eligibility for inclusion in the low-risk delisted
subcategory will be based on whether the risks from that particular
source, as proven by its specific facts, are within our pre-established
criteria that are based on the statutory levels defining when a source
category or subcategory may be delisted.
B. Background Pollution and Co-Located Emission Sources
Comment: One commenter stated that many of the HAP emitted from
PCWP facilities are found ubiquitously in U.S. ambient air and,
therefore, a risk assessment methodology that ignores background
pollution (including co-located sources) underprotects. The commenter
noted that the 2003 proposal notice recognized that simply ensuring
that the risks caused by PCWP sources themselves were below a hazard
index (HI) of one (without accounting for other sources of exposure)
would be underprotective. However, in the final PCWP NESHAP, EPA
decided to use an HI of 1.0, but did not require sources to account for
background pollution or emissions from co-located sources, thus failing
to ensure that sources are truly low-risk. Two other commenters noted
that the final PCWP NESHAP limits the analysis of risk to the impact of
selected emissions units, but the major-source status of a source is
based on facilitywide emissions.
Other commenters argued that EPA correctly refrained from
considering risks from background ambient HAP concentrations and from
co-located sources. One commenter also noted that EPA selected a very
conservative HI of 1.0, which builds in a margin of safety in the event
that exposure to background sources of HAP increases the risk to public
health. Therefore, EPA has in a way accounted for background and co-
located source emissions in formulating the low-risk subcategory. The
commenter added that CAA section 112(d) and 112(c)(9) address source
categories established pursuant to CAA section 112(c)(1) without regard
to background or co-located sources outside the source category.
Another commenter added that CAA section 112(c)(9)(B) delisting
criteria pertaining to both threshold and non-threshold HAP are focused
solely on exposures attributed to the affected source in question. The
commenter believes the statutory criterion in CAA section
112(c)(9)(B)(i) is clearly defined (one in a million cancer risk) and
is to be evaluated solely with reference to the emissions from affected
sources, not background concentrations. The commenter believes that
``ample margin of safety'' delisting criterion for threshold HAP in CAA
section 112(c)(9)(B)(ii) is more than adequately achieved by the
combined conservatism of the dose/response assessment (inherent in the
derivation of the reference concentration (RfC) or other inhalation
benchmark) and the exposure assessment (inherent in the dispersion
modeling methodology and the assumption of continuous exposure to the
maximum average annual emissions for the duration of a lifetime).
Response: We do not believe that it is necessary or appropriate to
consider background HAP concentrations or HAP emissions from co-located
sources in implementing our authority to delist the low-risk PCWP
subcategory. After reviewing the comments and reconsidering the
relevant sections of the CAA, we agree with the commenters who argued
that section 112(c)(9) decisions may be based on risk assessments that
focus on the emissions from the affected source and are not required to
consider co-located source emissions or background concentrations. The
residual risk program may consider, as appropriate, risks from co-
located source emissions and risks from total emissions from a
particular location. This approach is reiterated in the recently
finalized Coke Oven Batteries Residual Risk rule 70 FR 19991 (April 15,
2005), where we said we will only consider emissions from the regulated
source category when determining acceptable risk during the first step
of the residual risk analysis. However, during the second step, where
we determine the ample margin of safety considering costs and technical
feasibility (70 FR 19997-98), we may consider co-located sources and
background levels where appropriate. Additionally, the national
strategy for area sources will address emissions from multiple sources
in urban areas.
Comment: One commenter contended that the authors of the MACT and
delisting provisions at issue made clear that they intended all co-
located sources of HAP to be included when EPA made risk-based
decisions. The commenter provided examples of legislative history of
the 1990 CAA amendments which the commenter believes explains
Congressional intent in crafting section 112(c)(9).
Another commenter contended that Congress intended EPA to focus
only on the source in question, and provided examples from the
legislative history of CAA section 112(d)(4), which according to the
commenter is an analogous provision. The commenter argued that Congress
was clear when it intended for EPA to consider background
concentrations and contributions from all sources. The commenter
provided examples from the CAA and judicial precedent.
Response: While we believe that under section 112(f) we may
consider, as appropriate, co-located source and background emissions
when conducting residual risk reviews, after reviewing the comments and
the different statutory language in section 112(c)(9), we do not
believe it is necessary or appropriate to consider emissions except
those from the affected source category or subcategory at issue. This
is because the specific language of section 112(c)(9), compared to that
in section
[[Page 8347]]
112(f), indicates that the focus of a delisting action should be on the
risks presented by the emissions from the affected source category or
subcategory itself, rather than from other sources.
The criteria for a delisting decision regarding a source category
that emits carcinogens are discussed in section 112(c)(9)(B)(i) in a
way that suggests EPA is to start its analysis by first identifying the
sources ``in'' (i.e., the process units that make up the affected
source) the source category, and determine whether HAP ``emitted by''
such affected sources ``in'' the category exceed quantities that cause
a lifetime cancer risk greater than one-in-one million to the
individual who is most exposed to emissions of ``such pollutants from
the source[.]'' This focus on emissions from sources that are actually
within the source category as being the scope of HAP concentrations
that must not exceed the enumerated cancer risk benchmark would be
frustrated by an analysis that imports HAP emissions from other sources
not in the source category, or that includes background HAP
concentrations that may not be attributable to any source at all.
Similarly, section 112(c)(9)(B)(ii) provides that for non-
carcinogen HAP, EPA is to assess whether emissions ``from no source in
the category or subcategory'' exceed a level adequate to protect public
health and whether emissions ``from any source'' in the subject
category or subcategory will cause an adverse environmental effect.
Again, the statutory language focuses on the emissions that are
attributable to sources within the source category or subcategory under
review, and does not direct EPA to extend its analysis to either
emissions from other sources in other categories or subcategories or to
non-attributable background concentrations.
Contrast this with the language of section 112(f)(2)(A), which,
initially, directs EPA to determine whether further risk-based
standards are required in order to provide an ample margin of safety to
protect public health to prevent an adverse environmental effect,
without specific reference as in section 112(c)(9)(B)(i) and (ii) to
the emissions from sources within the source category in question. This
difference alone suggests that EPA may take a broader look in assessing
risks under section 112(f) than is required under section 112(c)(9).
Moreover, in establishing the trigger for when EPA is required to adopt
residual risk standards, section 112(f)(2)(A) focuses on the lifetime
excess cancer risk to the individual most exposed to emissions from
sources in the subject category or subcategory, but does not, like in
section 112(c)(9)(B)(i), clearly indicate that the excess cancer risk
is to be that caused only from the emissions from the sources within
the subject source category. Rather, under the language of section
112(f)(2), EPA may consider the cancer risk experienced by the most
exposed individual, whatever the source or sources of that risk may be,
and then regulate if the subject source category contributes to that
risk. A similar analysis applies to section 112(f)(2)(A)'s directive to
assess whether further standards are necessary to prevent an adverse
environmental effect, which, unlike the language in section
112(c)(9)(B)(ii), does not specifically state that such effect must be
caused by emissions from the sources in the subject source category.
Finally, the language in section 112(f)(2)(A) that establishes the
threshold of protection residual risk standards must achieve also does
not explicitly limit EPA's authority to focusing only on the emissions
from the affected sources in the subject category.
Therefore, while both section 112(f)(2) and 112(c)(9) use the
phrase ``ample margin of safety'' to define the triggers for action
and/or the benchmark that must be met in action, the differences in
additional contextual language in the two subsections makes it
reasonable to interpret section 112(c)(9) as allowing a more narrowly
focused risk assessment for source category and subcategory delistings
than the agency has stated it intends to pursue in residual risk, in
which we have asserted the ability to evaluate ``other relevant
factors'' beyond those presented by the affected source (70 FR 19998).
Comment: One commenter stated that if the final PCWP rule
incorporates risk-based exemptions, sources included in the low-risk
subcategory should not be exempted from consideration during the
residual risk process. Other commenters argued that EPA does not have
authority to consider facilitywide or background emissions in residual
risk determinations.
Response: We disagree that we do not have the authority to include
the entire facility in our residual risk analyses. In the preamble to
the coke ovens residual risk rule, we reiterated our discretion to
include, as appropriate, emissions from outside the source category
during the ample margin of safety determination. The emissions
evaluated during this ample margin of safety determination can include
those from PCWP sources that are part of the low-risk subcategory.
C. Ecological Risk
Comment: Two commenters stated that the risk-based exemptions in
the PCWP rule do not address ecological risks that may result from
uncontrolled HAP emissions. One of the commenters believes that EPA's
ecological assessment for the final rule is fundamentally inadequate.
The commenter believes EPA failed to meet the legal requirement in the
CAA in several obvious ways: (1) The assessment focused on just a few
HAP and thus ignored potential environmental impacts from other
emissions; (2) by evaluating a single location, the assessment ignored
potential site-specific environmental receptors and locally affected
species; and (3) the consideration of only persistent and
bioaccumulative HAP would not capture potential acute effects on the
environment.
To the contrary, one commenter believes that EPA properly evaluated
ecological risks. The commenter referred to their study of ecological
risks which the commenter believes concurs with EPA's findings that no
potential adverse risk to ecological resources is likely based on the
available data.
Response: To determine whether low-risk PCWP sources are likely to
cause adverse environmental effects due to HAP emissions, EPA performed
a screening assessment of ecological risks from these sources. The
ecological assessment focused on HAP that are emitted by PCWP
facilities and that have the potential to persist in the environment
and bioaccumulate. The list of persistent and bioaccumulative HAP (PB
HAP) is described in EPA's Air Toxics Risk Assessment (ATRA) Reference
Library (http://www.epa.gov/ttn/fera/risk_atra_main.html). We did not
evaluate inhalation risks of non-PB HAP to ecological receptors
explicitly. Rather, we assert that the acute and chronic dose-response
values for human inhalation exposure, which will be used by PCWP
facilities to demonstrate their low-risk status, are protective of
inhalation exposures that may be experienced by many terrestrial
animals. Human dose-response values are derived from studies that
consider human data and data from laboratory animals. With the addition
of uncertainty factors, the final dose-response values are generally
substantially lower than the level observed to cause an adverse effect
in exposed animals. Therefore, if the maximum inhalation hazard to
humans, which is the major basis for the LRD, is below the level of
concern, we do not expect adverse effects on environmental
[[Page 8348]]
receptors due to inhalation exposures. For the HAP that must be
included in PCWP LRD, and for which ecological inhalation toxicity
values are readily available, the human inhalation dose-response values
are protective for inhalation exposures to ecological receptors when a
hazard quotient or HI of 1.0 is used. For the details of this
comparison see the memo titled, ``Comparison of ecological inhalation
toxicity values to human health inhalation toxicity values for HAP that
must be considered in Low-Risk Demonstrations (LRDs) from sources in
the Plywood and Composite Wood Products (PCWP) source category''.
For the assessment of persistent or bioaccumulating HAP, we made
several ecosystem-protective assumptions. We derived estimated worst-
case media concentrations by assuming the maximum air concentrations
and the maximum deposition rates occurred at the same location,
although this is often not the case. We examined six locations
representing diverse meteorological conditions, and for the final
assessment, we used the location providing the highest predicted HAP
concentrations. We used the most conservative ecological screening
values readily available, which may overestimate the potential for
toxicity to site-specific populations and communities. Finally, we
assumed 100 percent bioavailability of the HAP, although site-specific
bioavailability is often much less. The results of our ecological
assessment demonstrate that for all pollutants assessed, and for all
pathways assessed, the ecological hazard quotient values are less than
1. The highest hazard quotient is 0.043, or more than 20 times below a
level of potential concern. Given this result, and the ecosystem-
protective nature of the assessment scenario, we do not believe that
HAP emitted from PCWP facilities will harm local ecosystems. Therefore,
we conclude that HAP emissions from any source that demonstrates
eligibility to join the low-risk PCWP subcategory will not cause an
adverse environmental effect.
D. The Dose-Response Value Used for Formaldehyde
Comment: One commenter noted that in proposing the risk-based
exemption idea, EPA indicated that it would use unit risk estimates
(UREs) from EPA's Integrated Risk Information System (IRIS) to
calculate whether or not a given source is low-risk. However, in the
final rule, EPA relied on a much lower value derived by the CIIT
Centers for Health Research (CIIT)(previously the Chemical Industry
Institute of Toxicology) using a model that estimated the carcinogenic
effects of formaldehyde on the respiratory system.
Several commenters recommended that EPA continue to use the IRIS
potency factor for formaldehyde until EPA has completed its thorough
review process (including public review) and updated IRIS. The
commenters stated that adopting a factor that has not undergone the
full IRIS review process jeopardizes public health. The commenters
recommended that EPA accelerate completion of the IRIS review.
To the contrary, one commenter believes that EPA properly evaluated
the carcinogenicity of formaldehyde by abandoning the outdated and
scientifically inaccurate IRIS value and instead relying on evidence
that has received broad acceptance in the international scientific
community. The commenter also believes that IRIS is far from
definitive, as EPA resource constraints have resulted in many chemical
summaries that are significantly outdated. The commenter contended that
EPA management has repeatedly emphasized that EPA is required to
consider other information, in addition to the IRIS database, when
evaluating the health effects of chemicals in a regulatory context.
Response: We agree with the first commenters that we should use the
best available sources of health effects information for risk or hazard
determinations. As we have stated previously, we do not rely
exclusively on IRIS values. Rather, we consider all credible and
readily available assessments.\2\ For air toxics risk assessments, we
identify pertinent toxicity or dose-response values using a default
hierarchy of sources, with IRIS being the preferred source, to assist
us in identifying the most scientifically appropriate benchmarks for
our analyses and decisions. The IRIS process contains a peer-review
process, and the resulting values represent EPA consensus. When
adequate toxicity information is not available in IRIS, we consult
other sources in a default hierarchy that recognizes the desirability
of review and consistency with EPA risk assessment guidelines. This
process ensures that we have consistent and scientifically sound
assessments. Furthermore, where the IRIS assessment is relatively dated
and newer peer-reviewed assessments are available, we will consider the
full set of such assessments in selecting the basis for the risk
assessment. In the case of formaldehyde, we have determined that the
cancer potency derived using the approach developed by CIIT, which has
been peer reviewed by an external review panel sponsored by EPA and the
Canadian government, represents an appropriate alternative to EPA's
current IRIS URE for formaldehyde. Therefore, this potency represents
the best available peer-reviewed science at this time. We also agree
with the last commenter that the issue of changing health-based
guideline values is a general challenge in setting health-based
regulations. However, we are committed to setting such regulations that
reflect current scientific understanding, to the extent feasible. If
dose-response values change, PCWP sources in the low-risk subcategory
must ensure that they continue to meet the low-risk requirements in
appendix B to subpart DDDD using the revised values. If PCWP sources no
longer meet those low-risk criteria due to a change in a peer-reviewed
dose-response value selected by the Agency for those assessments, that
source must comply with the technology standards of the PCWP MACT.
Facilities conducting LRD should refer to appendix B to subpart DDDD of
40 CFR part 63 for guidance on choosing appropriate dose-response
values.
---------------------------------------------------------------------------
\2\ U.S. Environmental Protection Agency. 1999. Residual Risk
Report to Congress. Office of Air Quality Planning and Standards,
Research Triangle Park, NC 27711, March 1999, EPA-453/R-99-001;
available at http://www.epa.gov/ttn/oarpg/t3/meta/m8690.html. (EPA
1999)
---------------------------------------------------------------------------
Comment: Several commenters submitted in-depth comments relating to
the CIIT report and carcinogenicity of formaldehyde. Some commenters
argued that the CIIT model for carcinogenic potency of formaldehyde is
limited in a number of ways, and needs further validation and peer
review. The commenters described recent epidemiological studies that
reportedly link formaldehyde exposure to leukemia. Other commenters
believe that EPA correctly evaluated the formaldehyde cancer potency
value for the final rule and stated that the CIIT risk assessment is
the best available science. The commenters disagreed that the
availability of new scientific studies justifies use of the outdated
IRIS value and argued that the new studies are flawed.
Response: As mentioned above, we are committed to using the best-
available science for our risk assessments. In situations where the
IRIS assessment lags behind current scientific knowledge and newer
peer-reviewed assessments are available, we will consider the full set
of such assessments in selecting the basis for the risk assessment.
These alternatives need to be grounded in publicly-available,
[[Page 8349]]
peer-reviewed information. In the case of formaldehyde, we have
determined that the cancer potency derived using the approach developed
by CIIT and peer-reviewed by an independent expert peer review panel
sponsored by EPA and the Canadian government represents an appropriate
alternative to EPA's current IRIS URE for formaldehyde, and is
therefore the best-available peer-reviewed science at this time.
However, we note that a comprehensive reassessment of cancer risk has
been initiated for IRIS. This reassessment will include modeling
analyses and endpoints (e.g., lymphohematopoietic cancer) not
considered in the CIIT assessment. We expect the IRIS reassessment to
be completed in 2007. The revised IRIS assessment will represent the
best-available peer-reviewed science at the time of its completion and
we will require LRD to use the revised URE that results from the
reassessment process.
E. Appendix B to 40 CFR Part 63 Subpart DDDD Requirements
1. Average Stack Heights
Comment: One commenter stated that the promulgated risk assessment
methodology allows a source to use average stack heights, which
decreases the accuracy of the risk assessment and may significantly
understate the risks from any given source. The commenter stated that
EPA's proposal to incorporate a weighted stack height for the look-up
tables only exacerbates the problem. The commenter predicted that
sources will only use the weighted stack height when it is to their
advantage.
Other commenters stated that the values in the look-up tables and
the use of average stack heights are not health protective under worst-
case conditions. The commenters stated that dispersion is a non-linear
function and it is impossible to try and simplify the effects of a
stack. For example, the impact of a 40-foot stack is not one half the
impact of a 20-foot stack. In fact, depending on the building heights
and the distance to the receptor, the impact of the taller stack could
be similar to the shorter one.
One commenter disagreed that use of average stack heights where
there are multiple emissions points may significantly understate risks.
The commenter pointed out that the LRD requires sources to use the
shortest distance to the property boundary, coupled with the average
stack height. The commenter believes that use of the shortest distance
to the property boundary would more than compensate for any
underestimates in exposure in any unlikely instances where lower
emitting sources have the taller stacks.
Two commenters supported EPA's proposal to replace the average
stack height calculation for the look-up tables in appendix B to
subpart DDDD with a separately computed toxicity-weighted stack height
corresponding to each of the three health effects. One commenter noted
that the large majority of emissions from wood products facilities
occur through relatively tall stacks. However, wood products facilities
also have many very low-emitting emission points that are quite close
to the ground. As promulgated, the rule requires these low-emitting
near-ground emission points to be averaged with the higher-emitting
stack emission points to develop an average stack height that
understates actual stack heights. Therefore, the promulgated approach
results in an overly conservative estimation of actual stack height
which, coupled with the conservative assumption of using the shortest
distance to the property boundary and the other elements of
conservatism built into the look-up tables, goes beyond what is needed
to protect human health with an ample margin of safety. The commenter
stated that the proposed toxicity-weighted stack height approach
addresses this issue in a reasonable and appropriate manner.
Another commenter agreed, arguing that assuming all emissions occur
at the location of the stack with the minimum distance to the property
boundary is unnecessarily conservative. The commenter recommended that
an appropriate average property boundary distance be calculated using
the same toxicity-weighted averaging procedure suggested for stack
height.
Response: We agree that the average stack height is not the best
metric for characterizing risks in a look-up table analysis. Appendix B
to subpart DDDD now requires the calculation of a toxicity and
emissions-weighted stack height for the look-up table analysis. Using
this approach, the emission points with the highest toxicity-weighted
emission rate will contribute the most to the stack height calculation
while the emission points with the lowest toxicity-weighted emission
rate will contribute the least. Thus, the weighted stack height metric
provides a more accurate characterization of a source's emissions
characteristics and it addresses commenters' concerns about under-
predicting risks for sources with most emissions coming from the
shortest stacks. Further, using this more precise method does not
undercut our reliance on other health-protective assumptions in the
look-up table analysis when most of the emissions come from taller
stacks.
Use of weighted stack height is not optional, but is required for
facilities performing the look-up table analysis in their LRD. We
proposed to replace the average stack height calculation with the
weighted stack height calculation.
Contrary to one commenter's statement, we do not assume dispersion
to be linear with stack height. Rather, the allowable emission rates in
the look-up tables are based on actual dispersion model runs using the
stack heights given in the table. Additionally, we agree that
collapsing across multiple stacks to generate a single weighted stack
height will not result in the exact same model output as if each stack
is modeled separately. However, use of the weighted stack height is a
simplifying step that is not expected to be consistently more or less
health-protective than modeling each stack separately. Because the
look-up table analysis is designed to be simple and because several
inputs to the tables bias them toward overestimating risks for most
sources, using a weighted stack height is appropriate in this context.
We agree with the commenter that, in cases where stacks are located on
top of buildings, building height can impact dispersion and risk.
Therefore, appendix B requires that when sources determine their stack
heights, they must use the height of the stack above the ground.
Therefore, if a stack is located on top of a building, that building
height is incorporated into the stack height value. We also agree with
the commenter that receptor location impacts risks. A look-up table
analysis inherently incorporates health-protective assumptions
regarding receptor location. The allowable emission rates in the look-
up tables are based on the maximum predicted offsite pollutant
concentrations, regardless of whether that site is populated.
Additionally, sources must use the shortest distance between an
emission point and the property boundary when conducting a look-up
table analysis. Therefore, sources using the look-up tables must assume
that all HAP emissions are coming from the emission point closest to
their property boundary, that people live at the location of maximum
predicted pollutant concentration, and that they remain at that
location for a lifetime. This approach is more health-protective than
if actual facility configuration and/or the location of actual
populations were to be considered.
We also disagree with changing the minimum distance to property
boundary. We recognize that using the
[[Page 8350]]
minimum distance to property boundary may overestimate the ambient
concentration and exposure. However, the lookup table analysis is meant
to be health-protective and using the minimum distance to property
boundary helps ensure that this is the case.
2. HAP With No Health Benchmarks
Comment: One commenter stated that the promulgated risk assessment
methodology fails to account for all HAP emitted by PCWP sources,
omitting some HAP like propionaldehyde, one of the ``predominant'' HAP
emitted by PCWP sources. The commenter noted that EPA's methodology
would assign a zero cancer risk to any HAP for which EPA has yet to
estimate such a value, even if such HAP may well be carcinogenic.
One commenter stated that six HAP (acrolein, acetaldehyde,
formaldehyde, methanol, phenol, and propionaldehyde) make up 96 percent
of the emissions from wood products facilities. The only one of these
chemicals lacking a health benchmark is propionaldehyde. The commenter
stated that EPA could extrapolate a propionaldehyde health benchmark
from occupational exposure limits. Even using the resulting health
benchmark, the commenter's analysis has demonstrated that
propionaldehyde makes no meaningful contribution to individual source
risk.
The commenter noted that EPA conducted a preliminary analysis of
the risks associated with PCWP facilities which narrowed the substances
considered to eight HAP, suggesting that the other HAP either were not
emitted from these facilities or were emitted in such low levels as to
not be meaningful contributors to risks in the source category. The
commenter referred to a sensitivity analysis they commissioned and
stated that the available data indicate that pollutants without health
benchmarks do not have the potential to influence risk results for wood
products industry. Accordingly, the commenter believes that EPA was
justified in not requiring sources to consider the potential risks of
pollutants emitted by wood products facilities that do not have health
benchmarks.
The commenter disagreed that EPA has acted arbitrarily in assuming
zero cancer risk for HAP for which it has yet to estimate such a value.
The commenter noted that the petitioners want EPA to assume that all
chemicals for which EPA has not set a cancer potency value are
carcinogenic. The commenter believes the petitioners' approach would
prevent EPA or any regulatory agency from ever making any realistic or
meaningful evaluation of potential risks (in any context) and would
merely serve to confuse (and scare) the public by suggesting that
sources pose cancer risks when in fact they do not.
Response: We are committed to using the best science available for
our risk assessments. To maintain this standard, we are using the
default hierarchy of sources for cancer and non-cancer dose-response
values that was originally developed for EPA's National-Scale Air
Toxics Assessment (http://www.epa.gov/ttn/atw/nata/natsa4.html). When
developing this hierarchy, we considered conceptual consistency with
EPA risk assessment guidelines and the level of review incorporated
into the dose-response values from each source. The EPA's IRIS process
is the preferred source of dose-response values. When IRIS values are
not available, we consider the alternative sources in our hierarchy.
Additionally, in cases where the IRIS value lags behind the scientific
literature, we are committed to considering alternative, credible dose-
response values. Currently, we do not have an IRIS file for
propionaldehyde, and an assessment is not available from the
alternative sources in our hierarchy. However, appendix B to subpart
DDDD requires sources to update their risk assessments if parameters,
including dose-response values, change in a way that could increase
risks. Therefore, if an acceptable cancer potency or non-cancer
reference value for propionaldehyde becomes available, we will consider
whether this HAP should be included in risk assessments for PCWP
sources. One commenter suggested that we use a modified occupational
exposure limit for propionaldehyde. In the past we have modified
toxicity values developed for other purposes so that they can be used
for inhalation assessments that support non-regulatory, screening
applications. However, because in the present case the modified
exposure limit would be used to make regulatory decisions, such a dose
conversion is inappropriate, particularly in the absence of scientific
peer-review.
We agree that it is appropriate to limit the number of HAP that
must be included in PCWP affected source LRD to only those HAP that may
possibly result in meaningful contributions to the affected source
risk. However, we are not limiting the HAP included in the LRD to the
six HAP defined as total HAP in subpart DDDD of 40 CFR part 63
(acrolein, acetaldehyde, formaldehyde, methanol, phenol, and
propionaldehyde). We identified the most prevalent HAP based on mass
emitted for purposes of developing MACT compliance options because MACT
is technology-based (i.e., the same technology that reduces emissions
of the six HAP also reduces emissions of other organic HAP). The six
HAP defined as total HAP in subpart DDDD of 40 CFR part 63 are the HAP
that are most often emitted in detectable amounts from the most PCWP
process units, and these HAP make up 96 percent of the mass of
nationwide HAP emissions from the PCWP industry. However, the risks
associated with emissions of HAP are dependent on the mass emitted and
the relative toxicity of each HAP. Thus, the HAP emitted in the
greatest mass may not result in the most risk because the HAP may not
be as potent as other HAP emitted in lower mass. For example, methanol
is the HAP emitted from the PCWP industry in the greatest mass, but
because methanol is not as toxic as other HAP emitted (e.g.,
formaldehyde, certain HAP metals), it does not result in as much risk
as do other HAP.
The commenter is correct in that our preliminary risk analysis
conducted prior to proposal of the PCWP rule narrowed the list of HAP
emitted from PCWP affected sources. We acknowledge receipt of the
commenter's sensitivity analysis based on the data used in our pre-
proposal risk analysis. Following proposal, we conducted a more
detailed risk analysis to evaluate the merits of including a low-risk
subcategory in the final PCWP rule. This memo is available in the
docket and is titled, Risk Assessment for the Final Maximum Achievable
Control Technology (MACT) Rule for the Plywood and Composite Wood
Products (PCWP) Source Category. This post-proposal analysis considered
emissions of more than 30 HAP emitted from the PCWP source category.
Many of these HAP are only emitted in minute amounts that have been
detected from a small number of PCWP process units. Nevertheless, we
included them in our risk analysis to determine their contribution to
PCWP affected source risk. We reviewed the toxicity values for each HAP
and the mass of each emitted from PCWP affected sources to determine if
it would be appropriate to narrow the list of HAP that PCWP affected
sources must consider in their LRD. Based on our review, we determined
that 95 percent of the cancer risk at PCWP affected sources is
accounted for by the following HAP: acetaldehyde, benzene, arsenic,
beryllium, cadmium, hexavalent
[[Page 8351]]
chromium, lead, nickel subsulfide, and formaldehyde. We also determined
that 95 percent of the non-cancer risk at PCWP affected sources is
accounted for by the following HAP: acetaldehyde, acrolein,
formaldehyde, phenol, MDI, arsenic, cadmium, and manganese. We feel
that inclusion of these HAP in a demonstration of eligibility of the
low-risk PCWP subcategory is appropriate. Limiting the list of HAP that
must be included in the LRD to 13 HAP minimizes emissions testing
costs, while ensuring that the HAP that drive the risk at PCWP affected
sources are accounted for on a site-specific basis.
3. Topography and Weather Patterns
Comment: One commenter stated that EPA's methodology treats all
PCWP plants as though their local topography and climate are identical
and that factors like prevailing winds are ignored. The commenter
believes the risk assessment methodology should account for topography
since different topographical features may exacerbate HAP exposures.
The commenter stated that PCWP plants are located at widely varying
altitudes and attached a chart.
One commenter stated that the modeling behind the development of
the look-up table should consider downwash. Another commenter stated
that facilities in areas with complex terrain should not be allowed to
use the look-up tables because the assumptions used to develop the
look-up table could not possibly account for this scenario. The
commenter expressed concern that the look-up tables do not account for
the common use of rain caps and for the likely event of building
downwash.
One commenter disagreed that EPA's look-up tables fail to account
for topography and weather patterns. To the contrary, the commenter
noted that EPA made conservative assumptions (e.g., minimum fence line
distance, worst-case meteorology, safety factors built into RfCs and
UREs, and the assumption that plumes from all sources directly
overlap), such that the look-up tables would be more likely to
overestimate (rather than underestimate) actual risk. One commenter
stated that it is unlikely that consideration of terrain will
substantially affect the screening risk emission levels, given that
most PCWP facilities are located in areas characterized by flat or
gently rolling terrain.
Response: We disagree that we have not considered site-specific
differences between sources in the methodology of appendix B to subpart
DDDD. If sources conduct site-specific risk assessments, they should
either use site-specific data, including for meteorological and
topographical information, or they should use health-protective
defaults. For look-up table analyses, we have made a number of health-
protective assumptions, including worst-case meteorological conditions.
Therefore, even though the look-up tables treat all sources as if they
have the same meteorology, that default meteorology should result in
higher predicted risks than actual site-specific meteorology.
However, we do not agree that the protective measures inherent in
the look-up tables justify their use in all cases. As several
commenters identified, we recognize that site-specific factors such as
building downwash, the presence of rain caps, and complex terrain were
not accounted for in the SCREEN3 dispersion modeling used to create the
look-up tables. In situations where these factors can have a
significant impact on the risks presented by a source, we agree that
use of the look-up tables is not appropriate. Where we determine,
during the risk assessment review process, that the look-up tables are
inappropriate, sources would be required to demonstrate eligibility
using a site-specific risk assessment. If a source is unable to make
this demonstration, the source must then comply with the technology
standards in the MACT.
4. Children's Health Risk
Comment: One commenter stated that EPA's risk assessment
methodology does not adequately account for the sensitivities of
children to environmental stressors because the methodology relies on
pre-existing cancer potency estimates which are deficient with respect
to early-life exposures.
However, another commenter believes that EPA's cancer potency
factors are amply conservative to protect against potential childhood
cancer risk. The commenter stated that the unit risk factor (URF) is
specifically based on worst-case assumptions (i.e., linear multistage
model for calculating the URF and through the assumption that a person
will be continuously exposed for a lifetime).
Response: The EPA has issued revised Guidelines for Carcinogen Risk
Assessment (Guidelines) and also Supplemental Guidance for Assessing
Susceptibility from Early-Life Exposure to Carcinogens (Supplemental
Guidance) which deal specifically with assessing the potential added
susceptibility from early-life exposure to carcinogens. The
Supplemental Guidance provides an approach for adjusting risk estimates
to incorporate the potential for increased risk due to early-life
exposures to chemicals that are concluded to be carcinogenic by a
mutagenic mode of action. For these chemicals, the supplemental
guidance indicates that, in lieu of chemical-specific data on which age
or life-stage specific risk estimates or potencies can be based,
default age-dependent adjustment factors can be applied when assessing
cancer risk for early-life exposures. As EPA's hazard and dose-response
assessments are updated under the new Guidelines and Supplemental
Guidance, they will include consideration of the available information
with regard to mode of action and the potential for this determination.
Thus, when estimating cancer risks for the purposes of this regulation,
the current HAP-specific assessments must be consulted to obtain both
the current inhalation unit risk values and the determination as to
mode of action. Where EPA's assessment has determined that the chemical
is carcinogenic by a mutagenic mode of action, it is recommended that
the risk assessment developed for the purposes of this regulation
employ applicable life-stage specific potencies or age dependent
adjustment factors per the Supplemental Guidance when early life
exposure is expected to occur.
5. Distance to Nearest Residence
Comment: Commenters noted that the risk calculation depends upon
the distance any given source is to the nearest residence, ignoring the
possibility that there may be exposed people closer to the facility,
such as a school, day care center, or neighboring business. One
commenter stated that the most exposed individual is likely to be a
person who actually works at the PCWP facility as opposed to a person
beyond the facility fence line.
One commenter believes EPA should revise the risk screening to use
the distance to the property line instead of the distance to the
nearest resident. The commenter believes that both the look-up tables
and the site-specific screening should use the property boundary or the
point of maximum impact for the LRD.
A separate commenter disagreed that EPA should have required the
site-specific assessments to evaluate continuous lifetime exposure at
the nearest receptor (as opposed to the nearest residence), whether it
be a school, shopping mall or church. The commenter noted that the
promulgated PCWP rule allows risks to be computed at residential
locations with the highest modeled risk for site-specific assessments.
The commenter believes this is appropriate because EPA requires sources
to assume the worst-case
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exposure scenario (i.e., continuous, lifetime exposure for 70 years).
The commenter noted that people would not spend 24-hours per day, 365
days per year for 70 years at a school, shopping mall or church.
Although this exposure scenario is equally implausible for residences,
the commenter thinks that residential locations are a more appropriate
choice.
The commenter noted that the rule does not explicitly address the
receptors that should be applied for the acute exposure assessments
(which are required independently for acrolein and formaldehyde). The
commenter requested that the rule clearly state that for acute
exposures, the proper reference is to the property boundary rather than
to the nearest residence.
Response: In exercising our authority under section 112(c)(9), we
do not think it is appropriate to base our determinations on risks
presented at the PCWP facility due to occupational exposures, since
such risks are not caused by emissions of HAP into the ambient air
(i.e., since they are on the plant site, they are not beyond the plant
fence line and are therefore not into the ambient air). However, we do
agree that risks to individuals at other locations surrounding the
source could potentially exceed risks to individuals at nearby
residences. Therefore, we have modified appendix B to subpart DDDD to
indicate that, in addition to residences, risk assessments should
include consideration of other locations such as schools and day care
facilities. We note that, as we described in EPA's ATRA Reference
Library, sources can deviate from default exposure assumptions if they
can provide adequate justification for the deviation. Such deviation is
appropriate where exposure duration is limited in terms of hours per
day, days per week, and/or total number of years.
Look-up table assessments must use distance to property boundary,
not distance to nearest residence. This requirement, which uses the
point of maximum impact outside the property boundary, adds to the
health-protection provided by look-up tables. We agree with the
commenter that this is the preferred approach for the look-up table
analyses. However, we disagree that site-specific risk assessments
should be limited to the property boundary. If a site-specific risk
assessment uses nearest residences for their risk calculations, and if
new residences are constructed in an area of higher risk, sources must
re-assess their risks to ensure they continue to meet the criteria in
appendix B to subpart DDDD. If they no longer meet these criteria (e.g.
because someone moved closer to their facility), then the source is no
longer eligible for the low-risk subcategory. Such a source must then
comply with the technology standards in the PCWP MACT.
We agree that acute assessments should use the point of maximum
impact outside the facility's property boundary. This requirement is
stated explicitly in appendix B to subpart DDDD.
6. Criteria Included in Site-Specific Risk Demonstrations
Comment: One commenter stated that EPA gives sources the ability to
make source-specific demonstrations with a number of open-ended
criteria. For instance, the commenter noted that appendix B to subpart
DDDD allows any scientifically accepted peer-reviewed assessment
methodology for site-specific risk assessment, and instructs sources to
use health-protective default assumptions wherever site-specific data
are not available. Thus, the commenter believes the facility owner has
extreme control over how to assess its risks, and EPA provides few
bounds on its discretion to approve such assessments as sufficiently
scientifically accepted or health protective. Another commenter
believes that the rule does not require that the risk assessment
methodology be approved by any regulatory agency as scientifically
acceptable or applicable.
One commenter stated that the approach included in the final rule
is consistent with general risk assessment methodologies, including
recommendations from the National Academy of Sciences Science and
Judgment in Risk Assessment (1994) and has been standard EPA practice
for over a decade. The commenter noted that EPA specifies its
preference that sources conduct their site-specific risk assessments in
accordance with the ATRA Reference Library (Volume 2) should facilities
not pass the initial look-up table screening analysis. Sources also
have the option of using alternative modeling methodologies provided
they have undergone scientific peer review. The commenter believes that
this does not, in turn, give sources unfettered freedom, but does
recognize that new modeling approaches may be developed in the future.
Response: We continue to believe that providing sources with the
discretion to use any ``scientifically-accepted, peer-reviewed risk
assessment methodology'' (e.g., see EPA's ATRA Reference Library) is
appropriate. However, contrary to the assertions of some commenters,
this discretion is not unlimited. Section 7 of appendix B to subpart
DDDD presents specific minimum criteria for site-specific low risk
assessments. In order to demonstrate eligibility for the low-risk
subcategory, the site-specific risk assessment conducted by the
facility must meet the following criteria: (1) Estimate long-term
inhalation exposures through an estimation of annual or multi-year
average ambient concentrations; (2) estimate acute exposures for
formaldehyde and acrolein maximum 1-hour average ambient
concentrations; (3) estimate the inhalation exposure of the individual
most exposed to source emissions; (4) estimate individual risks over a
70-year lifetime for the chronic cancer risk assessment; (5) use site-
specific quality-assured data wherever possible; (6) use health-
protective default assumptions wherever site-specific data are not
available; and (7) contain adequate documentation of the data and
methods used so that it is transparent and reproducible. The ATRA
Reference Library provides examples of how a risk assessment can be
conducted. These examples include instruction in basic risk assessment
methodology, in determining what parameters to include in a risk
assessment, and in the constraints that should be placed on those
parameters. The documents within the ATRA Reference Library have been
peer-reviewed and were developed according to the principles, tools and
methods outlined in the 1999 EPA Report to Congress. However, the
guidance in the ATRA Reference Library may not be appropriate for all
sources. For that reason we believe that it is important for sources to
be able to consider alternative analytical tools as long as those
alternatives are scientifically defensible, peer-reviewed and
transparent per the criteria listed above. Additionally, we disagree
with the commenter that the risk assessment methodology will not be
approved by a regulatory agency. The EPA will be responsible for
reviewing all PCWP risk assessments, and part of that review will
include ensuring that an appropriate assessment methodology is used.
The EPA may disapprove any risk assessment that fails to meet the
criteria of appendix B to subpart DDDD.
F. Selection of Process Units and Emissions Determination Procedures in
Table 2A to Appendix B to 40 CFR Part 63 Subpart DDDD
1. Use of Emission Factors and Other Emission Estimation Procedures
Comment: Two commenters addressed EPA's proposed amendment to allow
facilities to use emissions
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factors in LRD for certain process units rather than conduct emissions
tests. One commenter strongly supported both EPA's decision to simplify
the calculation of emissions used in the risk assessments and the
concept of using default emission values for relatively low emitting
and/or hard-to-test process units because many of the process units
included in table 2A to appendix B to subpart DDDD cannot be tested
without research-level effort. Another commenter disagreed with the
proposal to allow facilities to demonstrate compliance with the
requirements of the low-risk subcategory using emissions factors and
emissions estimates instead of conducting emissions tests. The
commenter noted that EPA's own publications, including AP-42 and
reports by the Office of the Inspector General, state that the use of
emission factors for compliance purposes is inappropriate. According to
the commenter, this proposal does not satisfy the section 112(c)(9)(B)
requirement that EPA determine that all sources in a category emit HAP
at levels below identified risk thresholds prior to exempting the
category from applicable MACT standards. In addition, the approach does
not fulfill EPA's commitment to require ``enhanced monitoring'' from
all sources subject to a section 112 MACT standard.
Response: Appendix B to subpart DDDD provides methodology and
criteria for sources to demonstrate whether they are part of the
delisted low-risk subcategory. Sources that are part of the delisted
low-risk subcategory are not part of the PCWP source category.
Therefore, in developing the emission factors in table 2A to appendix B
to subpart DDDD, we used the maximum available emission rate, as
opposed to the average emission rate, to ensure that emission estimates
used for LRD are health protective and reasonably account for the
uncertainty associated with using emission factors.
Because the LRD are to be based on the cumulative risk from all
process units within each PCWP affected source, we are requiring that
each process unit be considered in the LRD. In developing table 2A to
appendix B to subpart DDDD, we considered the feasibility of emissions
testing for each type of PCWP process unit and chose to allow emission
factors to be used for selected hard-to-test process units. We believe
that most of the process units for which we would allow emissions
estimates in lieu of testing are minor contributors to the total HAP
emissions relevant to the LRD. Because sources may use only the most
health-protective emission factors for only hard-to-test process units,
we do not believe risk assessments will be less health protective with
the inclusion of emission factors.
Affected sources that are not part of the low-risk subcategory must
comply with the MACT requirements in subpart DDDD, and subpart DDDD
contains compliance monitoring requirements for all the process units
with control or work practice requirements under subpart DDDD. Sources
that demonstrate eligibility to join the delisted low-risk PCWP
subcategory, instead, are not subject to the section 112 MACT standard.
Therefore, the PCWP rule follows through with the commitment to require
all sources subject to section 112 MACT standards to conduct ``enhanced
monitoring.''
Comment: Two commenters addressed the use of maximum emission
factors and the use of statistically-derived emission factors in table
2A to appendix B to subpart DDDD. One commenter disagreed that EPA
should use statistically-derived emission factors because, in many
cases, there are insufficient data available to perform a statistical
analysis. The commenter stated that where there is sufficient data,
applying a statistical approach would not result in significantly
different values from those already provided in table 2A to appendix B
to subpart DDDD. The other commenter disagreed with EPA's use of
maximum emission factors for hard-to-test process units. The commenter
stated that some of the factors are so high that some sources will be
forced to attempt to find ways to test the hard-to-test process units.
The commenter suggested the EPA either multiply all emission factors by
0.75 (or some other constant) or study the data for each factor and
statistically select a lower factor that is still conservative and
guards public health but enables sources to avoid costly and
unproductive testing.
Response: We proposed to include in appendix B to subpart DDDD the
maximum emission factors available for each type of process unit
because we believe use of maximum emission factors builds conservatism
into the emissions estimates to help account for unit-to-unit
variability and ensures protection of human health. However, in the
preamble to the proposed amendments, we requested comment on using
other statistical approaches. We received only one comment in favor of
using a statistical approach, and the commenter did not provide any
basis for assuming that emissions from untested PCWP process units are
75 percent of the emissions from the highest-emitting process units for
which we have data. We recognize that some of the emission factors
presented in table 2A to appendix B to subpart DDDD are quite
conservative, that emission testing costs can be significant, and that
some process units cannot easily be configured for emission testing.
However, we disagree that use of the maximum emission factors is
unnecessarily burdensome to small plants and companies because becoming
part of the low-risk subcategory is only one option under subpart DDDD,
and it is an option provided to reduce the burden on PCWP facilities
that do not pose a significant risk to human health or the environment.
2. Blenders, Sanders, and Saws
Comment: One commenter disagreed that emissions testing is ``not
feasible'' for several process units, including blenders, sanders, and
saws. These sources are usually controlled by baghouses, which are
normally required to be tested for particulate matter (PM). Because HAP
emissions from these units can be high, the commenter recommended that
actual test data be used rather than emission factors.
Response: We disagree that we should require testing of blenders,
sanders, or saws. Methanol is the predominant HAP emitted from
blenders. Methanol can also be emitted from sanders and saws. Methanol
is not a HAP of concern for purposes of the LRD. Our emission estimates
indicate that the appendix B HAP emissions from blenders, sanders, and
saws contribute to, but are not likely to drive the risk determination
for a PCWP facility because the emissions of these same HAP from dryers
and presses exceed those from blenders, sanders, and saws.
Furthermore, based upon the information available to us, we
disagree that most blenders, sanders, and saws are controlled by
baghouses and that PM emission testing is normally required for these
process units. We maintain that very few blenders, sanders, and saws
are already configured for emissions testing. We also believe that we
have struck an appropriate balance between the process units that must
be tested and the process units for which maximum emission factor
estimates will suffice for purposes of the LRD. As a result, we are not
requiring emissions testing of blenders, sanders, and saws in today's
final amendments.
Comment: One commenter suggested converting the acetaldehyde value
for finishing sanders from 0.0028 lb/MSF \3/8\'' to a lb/MSF surface
area basis to be consistent with the other sander values.
Response: As requested, we have recalculated the finishing sander
acetaldehyde emission factor based on
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the production rate in terms of MSF/hr, and have included the revised
factor (0.0031 lb/MSF) in table 2A to appendix B to subpart DDDD.
3. Emission Estimates for Lumber Kilns and Small-Scale Kiln Testing
Comment: One commenter supported small-scale lumber kiln testing.
The commenter stated that full-scale lumber kilns are difficult to test
because they are leaky and have highly variable exhaust rates, and most
small-scale kilns do not have exhaust variability or fugitive emission
issues. The commenter also noted that there is literature comparing
results from small-scale kiln tests to the emissions from full-scale
lumber kilns. The commenter stated that if certain conditions and
guidelines are followed, the small-scale kiln tests can provide good
estimates of emissions from lumber drying. The commenter suggested
changes to the list of considerations for a small-scale kiln emissions
testing program that was suggested by NCASI and placed in the docket
prior to proposal of the amendments.
Response: We recognize the difficulties with testing full-scale
lumber kilns due to their variable exhaust flow rates, and we agree
that measurement of small-scale kiln emissions can provide data
representative of full-scale kiln emissions provided that certain
conditions are met. We have reviewed the commenter's suggestions for
the consideration list, and we have used the list (with revisions) as
the basis for the new appendix C to subpart DDDD of 40 CFR part 63.
Facilities that do not want to use the emission factors in table 2A to
appendix B to subpart DDDD may conduct small-scale kiln tests taking
into account the considerations described in appendix C to subpart
DDDD. Small-scale kiln tests that do not address these considerations
may be rejected during our review of the LRD. The considerations
described in appendix C to subpart DDDD apply only for small-scale
lumber kiln emissions testing conducted to provide data for the LRD
described under appendix B to subpart DDDD. Permitting authorities may
require different procedures for testing or estimating lumber kiln
emissions for purposes other than the LRD.
Comment: One commenter requested that EPA reevaluate the lumber
kiln emission factors in table 2A to appendix B to subpart DDDD.
According to the commenter, emission factors found in NCASI Technical
Bulletin 845 are based on the most credible data, and using those
factors generally results in much lower emissions than the values
selected for table 2A to appendix B to subpart DDDD in the proposed
amendments. The commenter expressed concern that using the values in
the proposed amendments may lead to facilities being improperly
classified as major sources of HAP.
Response: The emission factors presented in the proposed amendments
to appendix B to subpart DDDD are not intended to be used for major
source determinations. Facilities that are not major sources of HAP
emissions are not subject to subpart DDDD, and the LRD procedures are
therefore irrelevant for those sources. The emission factors in
appendix B to subpart DDDD are intended to be health protective and are
intended only for use by facilities choosing not to test their lumber
kilns for purposes of the PCWP LRD. As stated previously, facilities
that feel the emission factors presented in table 2A to appendix B to
subpart DDDD would over-estimate lumber kiln emissions for purposes of
the LRD have the option of supplying facility-specific test data for
their lumber kilns. States may require data to be obtained for major
source determination using methods other than those described in
appendix B to subpart DDDD.
4. Wastewater Emission Estimates
Comment: One commenter stated that table 2A to appendix B to
subpart DDDD should not require modeling of MDI emissions from
wastewater and process water. The commenter stated that MDI hydrolyzes
immediately upon contact with water, polymerizing into to an inert
polyurea, so any wastewater from these operations cannot contain MDI.
Response: The commenter's assertion reflects the findings presented
by the American Chemistry Council (ACC) Diisocyanates Panel in their
petition to remove MDI from the list of HAP under section 112(b) of the
CAA. Based upon the findings described in the petition, we agree that
it is appropriate to change the entry in table 2A to appendix B to
subpart DDDD to ``NA'' for wastewater/process water operations.
However, our action with respect to table 2A to appendix B to subpart
DDDD does not necessarily reflect our conclusions with regard to the
petition to delist MDI, which we are still reviewing at this time.
5. Emission Estimates for Tanks
Comment: One commenter stated that the current wording of the
definition of ``resin storage tank'' includes all resin additives, even
caustic and acid. Neither caustic nor acid contain formaldehyde,
phenol, or MDI, so emissions of the HAP of concern would not be
expected. Additionally, the commenter stated that vessels holding
powdered resin should not be considered resin storage tanks. The
commenter suggested a revision of the definition of ``resin storage
tank.'' The commenter also requested that EPA add a footnote to table
2A to appendix B to subpart DDDD to indicate that estimating emissions
for tanks that do not contain formaldehyde, phenol, or MDI is not
required.
Response: As proposed, table 2A to appendix B to subpart DDDD
specifies default emission rates for tanks with resin containing a
specific HAP or modeling using TANKS software. It was not our intent to
require TANKS modeling of formaldehyde, phenol, or MDI for tanks
holding resins without these HAP, but we realize that the language in
the proposed table 2A to appendix B to subpart DDDD could be
misinterpreted in this way. For the final amendments, we have revised
the language in table 2A to appendix B to subpart DDDD to specify that
emissions of a specific HAP need only be estimated if the tank holds a
resin containing that HAP, regardless of whether the estimate is
obtained using an emission factor or modeling. We also agree that it is
not necessary to model emissions from powdered resin storage vessels,
so we have amended the definition of ``resin storage tank'' to include
only liquid resins and additives.
Comment: One commenter stated that the emission factors included in
table 2A to appendix B to subpart DDDD for resin storage tanks are
grossly over-estimated and the alternative techniques suggested by the
table are limited and overly simplified. In addition, the commenter
stated that there can be a significant difference between average
(long-term) and maximum hourly (short-term) emissions. The emission
factors should be reduced by a factor of at least 50 for short-term
estimates and 100 for long-term. The commenter provided sample
calculations to support reducing the emissions factors.
Response: We are aware that the default emission rates contained in
proposed table 2A to appendix B to subpart DDDD for resin storage tanks
are health protective. These emission rates represent the highest
emission rate reported for any single tank in the MACT survey
responses. Understanding the limitations of the default emission rates,
we also provided modeling using EPA's TANKS software as an option for
facilities who wish not to use the conservative default emission rates.
To alleviate concerns about these emission rates, we have reevaluated
the default emission rates for formaldehyde and
[[Page 8355]]
phenol. Because of the limited applicability of the emission rates
provided in the MACT survey results, we used other conservative
information from the MACT survey as inputs to the TANKS model to
generate emission estimates. We arrived at default emission rates of
0.001 pounds per hour (lb/hr) formaldehyde and 0.0002 lb/hr phenol.
Section 7(b)(1) of appendix B to subpart DDDD requires estimation
of annual average ambient concentrations for the chronic part of a
site-specific risk assessment, and Sec. (7)(b)(2) requires estimation
of maximum short-term (hourly) emissions of formaldehyde and acrolein
for purposes of estimating acute risk. One way to account for both
acute and chronic exposures is to assume the worst-case for all
emissions inputs to the risk model used to complete the acute and
chronic portions of the analysis. Although some facilities may choose
to use different emissions inputs in their site-specific LRD for the
chronic and acute portions of the assessment, we disagree with the
commenter that it is necessary for us to provide separate resin storage
tank default emissions rates for average (long-term) and maximum hourly
(short-term) emissions.
Comment: One commenter stated that table 2A to appendix B to
subpart DDDD should identify specific techniques for estimating
emissions from open-top tanks separately from techniques used to
estimate emissions from closed-top tanks. These types of tanks are
often used for mixing water and other additives into the resin. The
commenter provided an equation for estimating these emissions from the
2002 EPA Risk Management Plan (RMP) Offsite Consequence Analysis
Guidance (Appendix D).
Response: Several different approaches may be used to estimate
emissions from open-top tanks, including, for example, the 2002 EPA RMP
Offsite Consequence Analysis Guidance (Appendix D) noted by the
commenter. A similar approach is documented in Chapter 8, section 4.4
of an Emission Inventory Improvement Program (EIIP) document entitled
``Methods of Estimating Air Emissions from Paint, Ink, and Other
Coating Manufacturing Facilities.'' In addition, WATER9 or the approach
outlined in forms VII and VIII of appendix C to 40 CFR part 63 (and
described further with respect to the PCWP industry in a supporting
memorandum) could be used to estimate emissions from open-top tanks.
Rather than dictating specific methods to be used to develop estimates
of open-top tank emissions, we have amended table 2A to appendix B to
subpart DDDD to distinguish between open and closed resin storage tanks
and added a row to state that engineering estimates must be developed
for open resin storage tanks if they hold resin with any formaldehyde,
phenol, or MDI content.
6. Insignificant Activities
Comment: One commenter stated that the phrase ``may emit'' included
in the description of ancillary process units is elusive and could
include emissions of any amount of HAP, no matter how small. The
commenter requested that lists of insignificant and trivial activities
be included in appendix B to subpart DDDD to streamline the process of
preparing LRD. The commenter noted that the title V program allows
emission units with insignificant or trivial emissions to be specified,
but no emission estimates or permit limits are required. The commenter
(and other commenters) provided suggested lists of insignificant and
trivial emission units. Alternatively, the commenter suggested that the
final amendments could explicitly allow a facility to list all the
insignificant emission units in the PCWP source category at the
facility and make a blanket ``engineering estimate'' evaluation that
they are insignificant and their emissions are presumed to be zero. The
commenter noted that if EPA disagrees with the facility's designation
of an emission unit as an insignificant emission unit during its review
of low-risk determination, then it can notify the facility that
additional justification of its engineering estimate is needed for that
emissions unit.
Response: The amended rule does not include lists of insignificant
or trivial activities for several reasons which are documented in the
BID for the final amendments. Instead, we have adopted the commenter's
alternative suggestion. Each facility completing a LRD may include a
site-specific list of insignificant activities for which the facility
may make an engineering estimate of presumably zero appendix B
emissions. The facility must provide rationale to document placement of
each process unit or activity on the list (e.g., the unit does not
process HAP-containing materials; no heat is applied; there is no
mechanism for appendix B HAP formation, etc.). We will evaluate each
facility's list of insignificant activities when reviewing the LRD. Any
data that support the placement of a certain activity on the
insignificant activities list should be included with the facility's
LRD. Only process units and activities within the PCWP affected source
should be included in this list.
Comment: One commenter noted that EPA did not include a definition
of ``ancillary processes'' in the rule and suggested a possible
definition.
Response: We agree that a definition of ``ancillary processes'' is
needed since the term is used in table 2A of appendix B to subpart
DDDD, and we have defined the term in section 15 of appendix B to
subpart DDDD based on the definition suggested by the commenter (with
necessary edits).
7. Other Specific Comments on Table 2A to Appendix B to Subpart DDDD
Comment: One commenter requested that a footnote be added to the
formaldehyde emission factor for particleboard and medium density
fiberboard (MDF) blending and forming operations in table 2A to
appendix B to subpart DDDD. The footnote should state that the factor
applies only to facilities using formaldehyde-based resins.
Formaldehyde emissions from facilities that use 100% non-formaldehyde
resins or adhesives (such as MDI) should be designated ``NA.''
Response: We agree with the commenter that it is appropriate to
clarify that estimation of formaldehyde emissions from particleboard
and MDF blending and forming operations is only necessary for those
facilities that use resin containing formaldehyde. We have amended the
final rule to include such a footnote.
Comment: One commenter supported excluding metals testing for
process units firing only natural gas or propane and stated that
footnote b of table 2A to appendix B to subpart DDDD should be revised
to clarify that no emissions estimates are required for direct-fired
process units firing natural gas or propane.
Response: We agree with the commenter's suggested change to the
footnote b of table 2A to appendix B to subpart DDDD and we have
amended the footnote as requested.
G. Emission Testing Requirements in Appendix B to 40 CFR Part 63
Subpart DDDD
1. Testing of Multiple Identical Dryers
Comment: One commenter supported the proposed amendment giving
facilities the ability to use emissions test data from one unit for
modeling of similar process units. The commenter stated that the
proposed amendment will help industry better manage emissions testing
costs and testing resources while ensuring data quality. Another
commenter stated that EPA should consider age as a factor when
determining whether units are similar.
[[Page 8356]]
As proposed, the amendment would inappropriately allow newer and
cleaner-operating equipment to be tested in place of older, more run
down equipment without any loss of emissions estimating accuracy.
Response: As a result of the second comment, we reviewed available
data to see if any correlations with age of the process units are
apparent. We concluded that we do not have the emissions test data
spanning decades necessary to confirm or refute the commenter's
assertion that age of the process unit is a crucial consideration. We
generally agree that process units that are considerably older could be
expected to have greater emissions than newer process units of the same
design, particularly if the older process units have not been well
maintained. Therefore, we have included age of the process unit as a
consideration when applying test data from one unit to another similar
unit at a plant site to be conservative. However, we wish to clarify
that we consider distinctions in the age of the process unit, for
purposes of the PCWP LRD, to be many years (e.g., 5 to 10 years) since
our data do not show increased emissions as process units age over a
few years.
Comment: One commenter suggested that EPA allow facilities to test
one of multiple stacks or vents when the gases in those vents have been
collected from the same process unit, originate from the same duct or
vent, and are not expected to differ in gaseous pollutant
concentration. The commenter clarified that this procedure should not
be allowed unless the emissions have been collected and then
subsequently divided (e.g., the procedure would be inappropriate for
multiple vents above a wood products press).
Response: We agree with the commenter that applying results from
one stack test to the emissions from multiple stacks is acceptable for
purposes of the LRD when the gases in those stacks or vents have been
collected into a single duct and subsequently divided and are not
expected to differ in gaseous pollutant concentration. We also agree
with the commenter that testing one of multiple process unit openings
or vents, such as the vents above a wood products press, should not be
allowed because the concentration from such vents could differ. We have
added a paragraph to section 5 of appendix B to subpart DDDD to
incorporate this suggestion.
2. Use of Previous Emission Tests
Comment: One commenter supported the proposed amendment to allow
facilities to use previous emissions test data for the purposes of LRD.
The commenter stated that the proposed amendment will help industry
better manage emissions testing costs and testing resources while
ensuring data quality. However, the commenter stated that rather than
limiting the use of previously determined emission factors to those
units that operate at the same conditions as during the emission test,
EPA should require the subject units to be operated in a manner that
would result in lower emissions. Another commenter stated that EPA
should consider age as a factor when determining whether units are
similar. As proposed, the amendment would inappropriately allow newer
and cleaner-operating equipment to be tested in place of older, more
run down equipment without any loss of emissions estimating accuracy.
Response: We agree with the first commenter that it is not often
possible for a process unit to be operated under the exact same
conditions as during a previous performance test. It was not our
intention for this provision to be interpreted quite so literally. We
have revised section 5(i)(3) in appendix B to subpart DDDD to state
that the subject process units must be operated in a manner that would
be expected to result in the same or lower emissions than observed
during the previous emissions test and that the process units must not
have been modified such that emissions would be expected to exceed the
results from the previous emissions test.
Regarding the second comment, we discussed the effects of process
unit age in a previous response. We are limiting previous data
submitted for purposes of the LRD to emissions test data gathered in
1997 or later. We picked 1997 as the cutoff date because we recognize
that a great deal of HAP emissions data was gathered for PCWP process
units during that year, and we do not believe that this data is
obsolete at this time provided the other conditions of section 5(i) of
appendix B to subpart DDDD are met.
3. Fuel Analysis To Determine HAP Metals Emissions
Comment: Two commenters supported EPA's suggestion of using fuel
analyses to estimate HAP metal emissions for direct-fired process
units. One of these commenters stated that EPA should allow PCWP
facilities to use procedures similar to those in subpart DDDDD, the
Industrial, Commercial, and Institutional Boilers and Process Heaters
NESHAP (Boilers/Process Heaters rule). This option would lower testing
cost yet provide a maximally conservative value that would be
protective of public health.
Response: We have decided to adopt a fuel analysis procedure
similar to the procedure described in the Boilers/Process Heaters rule.
Section 5 of appendix B to subpart DDDD includes a new paragraph
referring to the relevant sections of subpart DDDDD. Plywood and
composite wood products facilities may conduct a fuel analysis in lieu
of emissions testing for HAP metals for purposes of the LRD. The
relevant sections of the Boilers/Process Heaters rule include Sec.
63.7521(a) and (c) through (e); Sec. 63.7530(d)(1), (2), and (4); and
line 2 of table 6 to subpart DDDDD. For purposes of conducting a fuel
analysis for a PCWP LRD, ``total selected metals'' means the
combination of the metal compounds included in table 1 to appendix B to
subpart DDDD.
4. Formaldehyde and Phenol Test Methods
Comment: One commenter stated that NCASI Method CI/WP-98.01 should
be allowed for formaldehyde and phenol measurement in table 2B to
appendix B to subpart DDDD. The method is allowed in other parts of the
rule for measurement of formaldehyde, phenol, and methanol, but it was
not included in appendix B to subpart DDDD. The commenter stated that
using NCASI Method CI/WP-98.01 instead of NCASI Method IM/CAN/WP-99.02
would reduce sampling cost and complexity without sacrificing sampling
precision and accuracy.
Response: We agree that NCASI Method CI/WP-98.01, ``Chilled
Impinger Method for Use at Wood Products Mills to Measure Formaldehyde,
Methanol, and Phenol,'' is appropriate for measurement of formaldehyde
and phenol. We have added NCASI Method CI/WP-98.01 to table 2B to
appendix B to subpart DDDD for formaldehyde and phenol testing only.
To be consistent with the test methods allowed in subpart DDDD, we
have also edited table 2B to appendix B to subpart DDDD to allow use of
Method 0011 for formaldehyde and acetaldehyde, and to allow use of
Method 316 (40 CFR part 63, appendix A) for formaldehyde.
In addition, a revised version of NCASI Method IM/CAN/WP 99.02 has
been placed in Chapter III of the NCASI Methods Manual and the PCWP
docket. The NCASI made minor revisions to the IM/CAN/WP 99.02 method to
(1) clarify sections easily misunderstood or that did not provide
sufficient instruction and (2) to add some flexibility to the quality
assurance procedures and
[[Page 8357]]
criteria. We reviewed and agreed with these minor changes to the
method.
5. Determining MDI Emissions
Comment: One commenter suggested that EPA also consider the use of
EPA proposed Method 207, ``A Method for Measuring Isocyanates in
Stationary Source Emissions,'' for measurement of MDI emissions. Method
207 is expected to provide lower detection limits than EPA CTM-031 and
Method 320, which are already allowed to be used.
Response: We proposed Method 207 in the Federal Register on
December 8, 1997 (62 FR 64532). A copy of the proposed method may be
downloaded from http://www.epa.gov/ttn/emc/proposed.html. We intend to
make minor revisions to the method and promulgate it in appendix M to
40 CFR part 51 within the next few months. We will accept data measured
using the proposed Method 207 before the promulgated version of the
method becomes available. Once promulgated, the final method 207 will
appear in the Federal Register, appendix M to 40 CFR part 51, and on
http://www.epa.gov/ttn/emc/promgate.html.
H. Compliance Date for Existing Sources
Comment: In response to our request for comment on the issue,
several commenters requested an extension of the MACT compliance
deadline (October 1, 2007, for existing sources). One commenter stated
that EPA should consider a compliance deadline extension for all PCWP
sources because of uncertainties associated with the promulgated
amendments, or ``supplemental rule.'' The commenter stated that EPA
could give sources 3 years (the maximum amount of time for compliance
allowed by section 112(i)(3)(A) of the CAA) from the effective date of
the supplemental rule. The commenter requested a new compliance date of
August 1, 2008 (based on an extended LRD submittal deadline of March 1,
2008), and noted that this date is less than three years from the
anticipated promulgation date of the supplemental rule. A separate
commenter suggested extending the PCWP MACT compliance deadline to
March 1, 2009 (based on a suggested LRD submittal deadline of March 1,
2008). Another commenter suggested extending the PCWP MACT compliance
deadline to October 1, 2008 (based on a suggested LRD submittal
deadline of April 1, 2007). The above commenters also suggested that
EPA extend the compliance dates for sources that submit LRD that are
not approved by EPA.
One commenter disagreed that facilities that do not submit a LRD
should be granted any additional time to comply with MACT. The
commenter also stated that if an existing facility's LRD is not
approved, the facility should be given no more than one year from the
current compliance date to comply with all requirements of the rule.
Another commenter asserted that section 112(i)(3)(A) denies EPA
authority to extend the rule's compliance date beyond October 1, 2007
for sources whose LRD are disapproved or for all PCWP sources.
Response: We are promulgating a MACT compliance date of October 1,
2008 in today's final action. We are providing this new compliance date
for all PCWP sources (as opposed to only those sources that submit
LRD). We are making this change to the MACT compliance date because
today's final action results in revisions to several definitions in
subpart DDDD and to the testing requirements in appendix B to subpart
DDDD that are substantial and warrant revision of the MACT compliance
date.
Our proposal specifically asked for comments on whether to set a
new compliance deadline for all sources covered by the PCWP NESHAP. As
mentioned by the commenters, section 112(i)(3)(A) of the CAA specifies
that NESHAP for existing sources can have compliance deadlines of no
more than 3 years following the effective date of their promulgation.
The question then becomes which promulgation date to apply--July 29,
2004, which is the date the PCWP NESHAP was first promulgated, or
today's date, on which we are promulgating numerous revisions to the
rule. We interpret section 112 of the CAA as providing us with the
authority to re-set the compliance deadline for NESHAP, as appropriate,
in situations where promulgated amendments to the regulation are
significant and substantial enough to warrant revisiting the question
of how much time is needed for subject sources to comply with the
requirements of the rule, as amended. This includes situations where a
NESHAP is significantly revised to include additional control
requirements in response to either a court's remand of the original
rulemaking or a petition for reconsideration of the rule, or is so
revised on the agency's own initiative.
We agree with the commenters that noted that section 307(b)(1) of
the CAA specifically provides that the filing of a petition for
reconsideration of a rule does not postpone the effectiveness of the
rule. We do not consider the mere fact that a rule has become the
subject of a petition for judicial review or a petition for
administrative reconsideration to necessarily justify a re-setting of
the compliance deadline. As we stated in the final reconsideration
notices for the Brick and Boiler MACT rules (70 FR 69661, November 17,
2005 and 70 FR 76928, December 28, 2005, respectively), the
uncertainties raised by reconsideration do not in general necessarily
justify an extension of the compliance date. Instead, the facts of each
rule's potential revision and the degree of the significance of the
rule's amendments should be considered on a case-by-case basis. Where
EPA has amended a MACT standard in a significant way, we have found it
appropriate to set a new compliance date for the rule that takes into
account new requirements not contained in the original rule. The
relatively greater degree of changes we made to the overall PCWP rule,
which substantially affect how it will be implemented for the majority
of sources, as compared to changes we made to the Boiler MACT (we made
no changes to the Brick MACT due to reconsideration), for example,
justify a different outcome for the PCWP rule.
Thus, changes in expectations about the numbers and types of
sources that will need to obtain, install and certify pollution control
equipment to comply with the rule's requirements overall are
compelling. Since the 2004 rule's promulgation, we found that many,
even most, facilities expect to install controls or make other physical
changes to the mill to meet the low-risk criteria. While we recognized
in 2004 that some sources would have to make these changes to become
low risk, we did not predict accurately the number of sources that
would do so. Rather, we expected that sources needing to obtain,
install and certify controls would be primarily those remaining in the
MACT category, such that MACT-subject sources would face comparably
less competition from would-be low-risk sources in seeking available
vendors for those controls under the original compliance deadline of
October 1, 2007. We now have a better understanding that more sources
than we first anticipated in 2004, both MACT and low-risk sources, will
need to install controls and will be competing for the services of a
limited number of control device vendors.
In addition to the difficulties sources may encounter in installing
controls and testing emissions, before today's final action, some
sources faced uncertainty about whether they were part of the PCWP
source category as defined in the
[[Page 8358]]
2004 promulgated NESHAP. We received several requests from sources and
permitting authorities as to the applicability for certain types of
processes such as molded particleboard and curved plywood components.
We determined that many of these sources were part of the source
category, but few had associated control requirements. However, some,
we do not how many, may be required to control emissions (e.g., for a
dryer). These are sources, such as furniture manufacturers, who
believed they were not subject to the MACT standards in 2004. Since
that time, through definitional changes in today's final action and
assistance with applicability determinations, we have provided the
necessary clarifications so that these sources may begin the process of
determining their regulatory obligations, which could include
installation of emissions controls.
As stated above, we do not generally regard the perceived
``uncertainty'' related to the reconsideration and amendment process as
constituting a sufficient reason in and of itself for revising the
overall compliance date. We note that prior to our issuance of today's
final action, sources were able to begin emissions testing for purposes
of the LRD with little certainty of what the final potentially-revised
emissions testing requirements would be. Furthermore, the entire
content of appendix B to subpart DDDD was under reconsideration. While
this did not affect the effectiveness or applicability of the
originally promulgated requirements pending our rulemaking process, we
have learned that the reconsideration and amendment process did affect
source decisions about whether to comply with the MACT standards or to
apply to join the low-risk subcategory, which, ultimately, caused some
sources to delay decisions about MACT compliance.
The emissions testing that facilities must complete for purposes of
the LRD involves careful planning (e.g., deciding what process units to
test and for which HAP, selection of test contractors, selection of
test methods, test plan development, etc.) and the expense of such
testing depends greatly on the number of process units and HAP that
must be tested. Many facilities will likely plan and conduct emissions
tests that serve a dual purpose: (1) To determine emissions of the
appendix B HAP for purposes of the LRD, and (2) to determine
uncontrolled emissions levels to identify potential MACT compliance
options (e.g., to identify emissions averaging opportunities or see if
emissions fall below the production-based compliance option) should the
facility decide not to pursue the low-risk option. Facilities may view
it as more economical to conduct testing of multiple process units and
HAP combinations at one time than to repeatedly test individual process
units for a few HAP (e.g., because test methods covering multiple HAP
can be used, and there is less travel expense for test contractors if
multiple tests are completed in one trip). Once onsite stack sampling
is completed, laboratory analysis of the samples must be conducted and
test reports prepared. The emissions testing that PCWP facilities must
conduct, from the planning stage to receiving the final report, can
easily take 9 months to 1 year. More time may be required if the
testing company or laboratory does not correctly perform the tests or
analysis the first time due to the difficulty of some of the test
methods (e.g., relatively new NCASI test methods developed specifically
for the PCWP industry). While adding these methods add flexibility for
sources, sources did not know until today whether the final rule would
incorporate them. We also recognize that the number of testing
contractors with the equipment and familiarity needed to run the NCASI
methods is limited, and that there will be much competition for the
qualified testing contractors. Today's final amendments allow use of
more test methods applicable to the multiple HAP of concern than did
the 2004 final NESHAP (e.g., we are incorporating by reference the new
NCASI method ISS/FP-A105.01), and before today's final amendments
facilities were uncertain which methods would be acceptable. In
addition, today's final amendments allow other emissions determination
approaches such as small-scale kiln testing, fuel analyses to predict
HAP metals emissions, and modeling of tank or wastewater emissions. For
these reasons, many sources have delayed their emissions testing
activities until after today's final amendments are promulgated.
Emissions testing is only one step in completion of the LRD (i.e., it
will take several months to a year or more for PCWP facilities to
complete their LRD incorporating all of the emissions data and to
complete changes to their facility to ensure they can meet the low-risk
criteria on an ongoing basis). Although the changes to the overall rule
are significant and the CAA allows us to set a new compliance date 3
years from the promulgation of today's final rule, we concluded only an
additional 12 months beyond the original compliance date is necessary.
Comment: Two commenters stated that there is no reason why a source
should not be able to move from the MACT to the low-risk subcategory if
changes occur such that the facility qualifies as low-risk (e.g.,
equipment installation that reduces emissions or any future changes to
the health benchmarks for acrolein and acetaldehyde), even if the
facility qualifies after the MACT compliance deadline. The commenter
stated that although these facilities would have already incurred the
expense associated with MACT control installation, it may still be
worthwhile to be classified as low-risk because of the reduced
recordkeeping and reporting burdens.
Response: We agree that sources should be able to join the low-risk
subcategory before or after the MACT compliance date. Allowing sources
to become part of the low-risk subcategory after the MACT compliance
date gives facilities more time to complete any physical changes
necessary to operate as low risk, more time to complete their LRD, and
more time to complete their permit applications. Existing sources
needing extra time must comply with the MACT requirements in subpart
DDDD as of October 1, 2008 and until they are part of the low-risk
subcategory. Since the CAA does not prohibit us from adding sources to
delisted subcategories after the MACT compliance date and existing
sources must comply with MACT if not in the low-risk subcategory by the
MACT compliance date, allowing sources additional time to complete
their LRD is reasonable and should be allowed. Therefore, we have
revised Sec. 10 of appendix B to subpart DDDD accordingly.
I. Low-Risk Demonstration Submittal Dates for Existing Sources
Comment: Four commenters supported an extension of the LRD
submittal deadline established in the 2004 final rule. One commenter
supported the proposed revised date of April 1, 2007. Three additional
commenters suggested extending the LRD submittal date beyond the
proposed date of April 1, 2007, and requested that EPA adopt extensions
of the LRD and MACT compliance deadlines to March 1, 2008, and August
1, 2008, respectively. One commenter stated that most facilities did
not begin emissions testing upon promulgation of the PCWP rule because
they were aware that clarifying amendments would be forthcoming. The
commenters arrived at the March 1, 2008, low-risk submittal date by
estimating the amount of time that would be needed to complete each
[[Page 8359]]
of eight steps that influence the timing of completing a LRD,
including: Planning and performing emissions tests, completing a risk
assessment, securing the capital needed to make any changes to the
source, installing control devices or completing other physical
changes, selecting and hiring contractors and control device vendors,
coordinating the LRD activities of multiple facilities, receiving EPA
approval of the LRD, and preparing the application for a title V permit
modification.
Two commenters disagreed that EPA should extend the LRD submittal
date. One commenter believes that extending the LRD submittal deadline
would simply encourage sources to spend time and resources attempting
to obtain unlawful exemptions instead of dedicating themselves to
meeting the rule's cleanup standards by the 2007 compliance date.
Another commenter stated that some facilities have already completed
their LRD and are simply waiting for the amendments to be promulgated
before submitting them.
Response: As explained above, we have revised section 10 of
appendix B to subpart DDDD so that sources may become part of the low-
risk subcategory any time. Therefore, there is no deadline for existing
sources to become part of the low-risk subcategory in today's action.
Existing sources that are not part of the low-risk subcategory on
October 1, 2008 must be in compliance with the MACT standards in
subpart DDDD.
We realize that some existing sources will want to be part of the
low-risk subcategory by the MACT compliance date to avoid MACT
compliance. For those sources, EPA will review complete and well-
documented LRD received by February 1, 2008 and make every attempt to
notify sources of our determination of their eligibility to become part
of the low-risk subcategory no later than August 29, 2008. (A complete
and well-documented LRD includes emissions tests performed on the
facility as it will be operated and includes the documentation required
in appendix B to subpart DDDD.) We believe this approach balances the
time we need to review and approve (or disapprove) LRD with the time
sources need to complete activities associated with the LRD.
We do not know how many facilities will submit LRD on or by
February 1, 2008, but it could be well over a hundred. We plan to
review LRD in the order we receive them and encourage sources to submit
their LRD as early as possible. (We will review preliminary LRD based
on modeling and emissions factors before February 1, 2008 and as our
resources permit. Although these LRD will not be approvable, sources
that want a review of their LRD at this preliminary stage should engage
us as the earliest possible date.) We note that we may not be able to
interact with sources as we might have otherwise (e.g., ask for
clarification, recommend minor changes) as the MACT compliance date
approaches because of time and resource constraints. If we have many
LRD to review, we will likely return incomplete demonstrations without
further review. We will likely notify these sources that we could not
approve the LRD at that time. Sources whose LRD are deficient may re-
submit revised demonstrations, but we will likely not review re-
submittals until we have completed our review of all the other timely
and complete LRD we have first received.
As to the decision individual sources make regarding whether to
spend resources on demonstrating they are low risk, the decision is
theirs to make. Similarly, a source must determine for itself when to
submit its LRD. We encourage sources to submit their LRD before
February 2008 so that we have time to work with sources to resolve
deficiencies in their LRD and so that sources have time to resubmit
their LRD (if necessary) prior to February 1, 2008.
Comment: One commenter supported EPA's proposal to allow a
preliminary LRD that is based on proposed physical changes to the plant
that have not yet been completed or verified by stack testing. The
commenter noted that this approach addresses some timing concerns and
also helps to ensure that sources do not undertake expensive facility
changes only to find that EPA does not approve their LRD. The commenter
noted that EPA should give sources until the proposed April 1, 2007,
deadline (assuming this deadline is not extended further) to submit LRD
that are based on proposed physical changes at the plant, and the
facility should be required to complete the physical changes by October
1, 2007.
The commenter stated that, for sources making physical changes to
comply with the low-risk criteria, confirmatory emissions testing
should be required by the date on which performance testing for MACT
compliance is due in the 2004 final rule (i.e., 180 days after the
compliance deadline). This proposed timing makes sense because physical
changes to meet the low-risk criteria and physical changes to meet one
of the other compliance options follow similar engineering and capital
planning timelines. The commenter noted that sources not making
physical changes to their facilities should be allowed to conduct
emissions tests after the low-risk submittal date but before the
compliance date.
The commenter also supported EPA's proposal to allow sources to
submit a preliminary LRD that relies on emissions factors. However, it
is critical that EPA provide the source with confirmation that the
source has used an acceptable methodology and that, if emission testing
provides the results anticipated by the source, the source will meet
the low-risk criteria and its demonstration will receive final
approval. The commenter noted that allowing preliminary LRD will enable
EPA to spread the demonstration reviews over a longer period of time
because sources will submit their preliminary demonstrations earlier.
In addition, if the preliminary demonstration is not approved, sources
have more time to amend their demonstration or prepare for alternative
compliance options.
The commenter suggested that EPA allow facilities to propose in
their title V applications which process parameters will be limited and
state that the emission limits will be set as a result of the most
recent emission test. As a result of this change, States would not be
able to issue the title V permit revision prior to the facility
receiving approval of the LRD.
Another commenter argued that EPA would not have the time to
thoroughly review both a pre-clearance application and a subsequent,
emissions test-based verification that emissions do not exceed the
emission factor calculations presented in the LRD. The commenter
contended that EPA will likely focus on sources' pre-clearance
submissions (in which sources have every reason to be overly
optimistic) and pay only cursory attention to the subsequent compliance
demonstrations.
Response: Existing sources may submit preliminary LRD at any time,
including those without the required emissions tests and without
completing physical changes to the facility. However, existing sources
must complete the required emissions tests and physical changes to the
facility, submit the complete LRD to EPA, receive approval from EPA (if
the LRD is approvable), and apply for their title V permit revision
before becoming part of the low-risk subcategory. We will consider
preliminary LRD that do not contain the required emissions test data to
be incomplete and we will not approve any LRD submitted by existing
sources that do not contain this required information.
[[Page 8360]]
We recognize that it may be necessary to complete physical changes
to emission sources before the required emissions testing can be
conducted. Existing sources may now submit their LRD any time (as
opposed to July 31, 2006, as originally promulgated). While giving
sources more time to complete their LRD, we have minimized the amount
of time we will have to review the numerous LRD that we anticipate will
be submitted by February 1, 2008. Therefore, we will review
preliminary, incomplete LRD only before February 1, 2008. After that
date we will focus our efforts on reviewing complete LRD in fairness to
those facilities that are low-risk without having to make physical
changes to their emission sources and those facilities that completed
their physical changes and emissions testing before February 1, 2008.
As time allows, we will review and provide feedback to facilities
submitting preliminary LRD several months prior to February 1, 2008. In
addition, we will accept and attempt to complete our review of final
LRD (that contain the required emissions test data) submitted after
February 1, 2008 that are follow-up to preliminary LRD we have
previously reviewed. Subsequent LRD submittals are likely to use the
same risk assessment procedures and should not need as much time to
review.
Existing sources will have about 2 years to complete their LRD and
the necessary physical changes to their facilities between the time
today's final action is available and the February 1, 2008 LRD
submittal date. These 2 years, coupled with the availability of the
low-risk criteria and risk methodology published in the 2004 final
rule, should provide enough time for existing sources to become part of
the low-risk subcategory by October 1, 2008 if they wish and have
planned accordingly. Sources may also choose to submit their LRD later,
and comply with the MACT requirements in subpart DDDD on the compliance
date and until they become part of the low-risk subcategory.
J. Compliance Date for Affected Sources Previously Qualifying for the
Low-Risk Subcategory
Comment: Two commenters disagreed with the 3-year MACT compliance
extension for existing sources that are temporarily low-risk but begin
to operate outside of the low-risk subcategory due to a population
shift or change in dose-response values. One commenter stated that the
CAA requires existing sources to comply no later than 3 years after the
effective date and that EPA offers no legal justification or rationale
for the extra 3 years provided to PCWP sources that are no longer low-
risk.
Other commenters supported EPA's decision to allow sources in the
low-risk subcategory to have 3 years to comply with the MACT limits
when they are no longer part of the subcategory due to factors outside
their control. The commenters stated that this is consistent with the
normal 3-year period for sources to comply with a MACT standard after
the effective date. The commenters stated that a 3-year compliance
window is necessary to ensure the necessary steps are completed to
transition between the low-risk subcategory and MACT compliance.
Another commenter stated that this approach is exactly consistent with
the existing regulatory provisions for area sources which become major
sources (and thus are subject to MACT) and have 3 years to comply with
MACT.
The commenter believes EPA has closed a potential loophole, rather
than creating one as petitioners claim. That is, CAA section 112(c)(9)
includes no provision for sources becoming ``re-subject'' to MACT if
they no longer are low-risk. Rather, CAA section 112(c)(9) assumes that
once a category is delisted, all sources in that category are
permanently exempt from MACT. The commenter believes that, under the
statute, if the subcategory no longer qualifies as low-risk, EPA must
affirmatively relist the subcategory (and no deadline is provided by
which EPA must do so). Relisting the category, in turn, would require
EPA to promulgate MACT standards within 2 years, with compliance
another 3 years later (or, a 5-year process in total from the date EPA
decided to relist the category). The commenter believes that EPA has
adopted a more protective approach and required compliance within 3
years.
Response: We agree with the commenter who analogized sources in
this situation, where they lose low-risk eligibility due to changing
factors that are outside their control, to the way we generally address
area sources that undergo changes that subject them to MACT for the
first time. In both cases, a source that was previously not part of the
MACT-regulated category has become subject to MACT, and it is necessary
for us to anticipate a feasible period for bringing the source into
MACT compliance. Unlike the situation of a low-risk source that
undergoes a change that it should know may have an effect on its
ability to maintain low-risk status (for which we are retaining the
2004 final rule requirement that the source comply with MACT
immediately upon the change), a source whose low-risk status is
affected by changes outside of its control will need some time to
comply with MACT, especially where the installation of controls is
necessary. We appreciate the commenter's agreement that our approach
for ensuring that sources that lose their low-risk status timely comply
with PCWP MACT requirements is reasonable. However, we disagree with
the commenter's suggestion that the alternative to our approach is to
have to relist under CAA section 112(c)(1) either the ex-low-risk
source or the entire low-risk subcategory before subjecting that source
to MACT. This is because there are only two possible subcategories a
PCWP source can belong to: Either the MACT-regulated category, or the
delisted low-risk subcategory. If a low-risk source loses its
eligibility for membership in the low-risk subcategory, it necessarily
follows that it then rejoins the MACT-regulated category, since there
is no other PCWP category or subcategory for the source to join. Our
approach is intended to make this necessary transition occur
efficiently, effectively and fairly.
Since it is possible that the types of changes in this situation,
such as a change to a more stringent RfC, may have an impact on a large
number of previously low-risk sources, it is fair and reasonable to
establish a common compliance deadline for all such similarly affected
sources. In adopting the 2004 final rule, based on the information
before us, we determined that sources covered by the PCWP NESHAP would
need the full statutory 3 years to comply due to the expected schedule
for ordering and installing controls from the available vendors. Low-
risk sources that, due to changes outside their control, suddenly find
themselves in the PCWP MACT category, will essentially be placed in the
same position as were PCWP MACT sources upon promulgation of the rule--
that is, an event has occurred that has made them subject to the rule
even though they took no action on their part to trigger the event.
Likewise, those sources may very well then find themselves at the stage
of the process that PCWP MACT sources faced in 2004, and have to begin
finding a control vendor who can install controls on time. Based on the
information we have today, we continue to believe that the full 3 years
is needed for sources in this situation who become subject to MACT, and
we see no reason to treat the two situations differently as the same
process and obstacles will be faced by these sources. On the other
hand, for sources that initiate their own changes that would affect
their low-risk status,
[[Page 8361]]
we continue to believe that MACT planning must be built into those
sources' considerations, and therefore maintain the requirement that
they comply with MACT immediately upon undergoing changes.
K. Low-Risk Demonstration Submittal Dates for New Sources
Comment: Two commenters suggested that new sources submit a
preliminary LRD before startup. One commenter requested that EPA
clarify the procedures for new sources to be included in the low-risk
category by allowing the demonstration to be submitted during
construction using conservative factors, as provided for in Sec. 5(h)
of appendix B to subpart DDDD, with EPA approval prior to startup.
Subsequent testing could be conducted within 180 days to demonstrate
that actual emissions are below the rates used in the demonstration.
The other commenter stated that new PCWP facilities that plan to join
the low-risk subcategory should be required to submit a preliminary
eligibility demonstration with their pre-construction permit
application. That way, State and local agencies will know at the time
the construction permit application is submitted that the facility
plans to submit a LRD and may be exempted from the MACT requirements at
a later date. The commenter noted that subpart DDDDD (the Boilers/
Process Heaters rule) requires a preliminary eligibility demonstration
using emissions estimates, and it also requires the facility to verify
the data with source testing within 180 days of startup. The commenter
also noted that since there are no provisions in the CAA for extending
the compliance date for new sources, new sources that are denied the
risk-based exemption must comply at startup and State and local
agencies must include all the requirements of the PCWP MACT in their
permits.
In addition, one commenter stated that it is not possible for new
or reconstructed sources to conduct their emissions testing upon
initial startup because the rule requires the facility to be run at
maximum capacity during testing and new facilities take at least 3
months to reach maximum capacity. Therefore, submitting a LRD 180 days
after startup is not reasonable for new or reconstructed sources. The
commenter requested that new and reconstructed sources be required to
conduct stack testing within 180 days of initial startup and to submit
their LRD within 240 days of initial startup.
Response: Unlike existing sources, new sources cannot conduct the
required emissions testing prior to startup. Therefore, we agree that
requiring new sources to submit a pre-startup LRD would be useful. It
allows new sources to determine whether or not they are likely to be
low-risk facilities and helps permitting authorities by notifying them
which sources plan to demonstrate eligibility for the low-risk
subcategory. Therefore, today's final action requires new sources to
submit a pre-startup LRD at least 9 months prior to startup. The pre-
startup LRD must be based on the information (e.g., equipment types,
estimated emission rates, etc.) that will likely be used to obtain the
sources' title V permit and must incorporate the maximum emissions that
will likely be allowed under the title V permit. New sources will also
be required to submit a verification LRD, based on emissions testing,
where required.
Today's action provides three options for new sources who want to
become part of the low-risk subcategory. When new sources submit their
pre-startup LRD, they must indicate whether they intend to join the
low-risk subcategory based on their pre-startup LRD (option 1) or based
on their verification LRD (option 2). The third option is for new
sources to comply with the requirements of MACT in subpart DDDD at
startup and join the low-risk subcategory after startup using the
procedures for sources already in compliance with MACT provided in the
amended section 10(b) of appendix B to subpart DDDD.
The first option allows new sources to join the low-risk
subcategory based on their pre-start-up LRD (i.e., upon startup). The
EPA will review and approve (if approvable) the source's pre-startup
LRD prior to startup. The source must operate, and certify they are
operating, consistently with their pre-startup LRD. After startup, the
source must submit a verification LRD, based on the emissions
determination requirements in table 2A to appendix B to subpart DDDD.
The EPA will review the verification LRD. If the verification LRD does
not support the pre-startup LRD, the source must comply with MACT for
new sources immediately. This is not to say that the verification LRD
must match the pre-startup LRD exactly. In fact, we would expect that
the pre-startup LRD would be more conservative than the verification
LRD. So while the two LRD may differ, the verification LRD must
demonstrate that the facility can operate consistently as low risk and
that the facility operated as low risk based on the pre-startup LRD.
The second option is for new sources join the low-risk subcategory
based on their verification LRD (i.e., to operate consistently with
their pre-startup LRD at startup and join the low-risk subcategory once
EPA reviews and approves (if approvable) their verification LRD). The
new source would submit a pre-startup LRD and EPA would review it prior
to startup of the facility. The facility would then operate and certify
operating consistently with their pre-startup LRD. The source becomes
part of the low-risk subcategory when EPA approves (if approvable)
their verification LRD. As required for sources choosing option 1, if
the verification LRD does not support the pre-startup LRD, the source
must comply with MACT for new sources immediately. Also, as for sources
using option 1, we do not expect the pre-startup LRD to match the
verification LRD exactly, but do require that the source operate as low
risk from startup or comply with MACT.
New sources must submit an application for a significant title V
permit modification to incorporate the low-risk parameters from the
verification LRD into their title V permit within a year of their
startup date.
New sources choosing either option 1 or option 2 face enforcement
liability if the source's verification LRD source does not confirm
their low-risk status. If the verification LRD does not demonstrate
that the source is low risk, the source is out of compliance with MACT
from startup. While any source in the low-risk subcategory is out of
compliance with MACT if EPA is sued and judged to have wrongly approved
the source's LRD, pre-startup LRD might be subject to more scrutiny by
the public and more likely to face a challenge if the LRD was
insufficient. Sources choosing option 2 could also be challenged for
operating in violation of the MACT standard before EPA determines they
are part of the low-risk subcategory.
L. Legal Issues With Title V Implementation Mechanism
Comment: One commenter believes the title V implementation approach
for the CAA section 112(c)(9) low-risk exemptions adopted in the final
rule: (1) Attempts to create specific and federally enforceable legal
requirements, without notice-and-comment rulemaking, through an
informal exemption ``letter approval'' process conducted between a
source and EPA; (2) imposes those legal requirements upon States and
the public by employing a State-issued title V permit to establish
applicable requirements; (3) does so without providing States or the
public with any meaningful, legal opportunity to
[[Page 8362]]
comment on or challenge those requirements; and (4) does so all in
contravention of existing EPA legal interpretations and policy that
prohibit use of title V permits for such purposes. The commenter stated
that EPA does not identify another instance in which a statutorily-
required determination by the Administrator achieves its culmination
and embodiment in a title V permit, nor does EPA identify statutory
authority in CAA section 112 or title V indicating Congressional intent
to allow such a result. The commenter believes that this result
transgresses title V's function to incorporate pre-existing federally
enforceable applicable requirements into operating permits issued by
approved permitting authorities, following applicability determinations
by the approved permitting authority. The commenter stated that unlike
the Prevention of Significant Deterioration (PSD) or New Source Review
(NSR) permitting programs in which the rules contain criteria that are
subsequently rendered applicable requirements in federally enforceable
preconstruction permits, the risk exemption approval process gives
definition and content to the qualifying conditions in an
unenforceable, legally meaningless letter. The commenter noted that the
State authorities do not render the low-risk approvals, have no
ownership over them, and have no reason to stand behind them. The
commenter stated that the public does not have the public comment,
challenge, and petition opportunities afforded under title V for
ordinary State applicability determinations.
Finally, the commenter noted that governing EPA statutory and
regulatory interpretations prohibit the title V implementation approach
employed in the final rule. If the risk determinations, parameters, and
conditions exist exclusively in a title V permit and the title V permit
expires, the parameters and conditions of the risk exemption would no
longer exist as a legal matter. The existence of a legal document
independent of title V preserves the ability of permitting authorities
and EPA to reopen title V permits that failed to include all relevant
permit terms or to make corrections upon permit renewal. Also, title V
regulations allow a permitting authority to include a ``permit shield''
stating that compliance with the conditions of the permit shall be
deemed compliance with any applicable requirements as of the date of
permit issuance.
Three other commenters believe that title V permits represent an
appropriate implementation mechanism for ensuring that low-risk sources
never exceed the applicable risk thresholds. One of the commenters
agrees that a significant title V permit modification is suitable for
incorporating low-risk parameters. The commenter stated that the reason
that a significant permit modification would be needed to incorporate
the low-risk subcategory demonstration is found in 40 CFR
70.7(e)(2)(i)(A)(3), a minor permit modification ``gatekeeper,'' which
prohibits use of minor modification procedures where a provision would
require (or change) a case-by-case determination during the title V
permit process. The commenter believes title V is not creating the
applicable requirements, rather relevant low-risk parameters are
requirements grounded in appendix B to subpart DDDD.
Another commenter stated that the title V process envisioned by the
final rule is comparable to the synthetic minor permit process which
has been in use for years. The commenter believes that CAA section
112(c)(9) does not specify any mechanism whatsoever for ensuring that
sources in delisted categories remain below applicable risk thresholds.
Once they are delisted, emissions (and risks) can increase without
limitation unless and until EPA takes affirmative action to relist the
source category or subcategory. Here, however, EPA is mandating that
any source seeking inclusion in the low-risk subcategory agree to
enforceable permit conditions to ensure that the source continues to be
low-risk. The commenter argued that the procedure envisioned here is
virtually identical to the ``applicability determination'' process
under title IV of the CAA. The commenter believes the petitioner's
argument that the approach transgresses title V's function is based on
a misperception of how the risk-based approach would be implemented.
The commenter stated that EPA's approval of the LRD will be conditioned
on retention of relevant source parameters that are necessary to ensure
that the source remains low-risk. These parameters become federally
enforceable requirements that properly are included in the title V
permit.
Response: The EPA agrees that the commenter who objected to the use
of title V permits as an implementation tool in the low-risk process
reflects a fundamental misunderstanding of what is required by the CAA
in the delisting context with respect to sources who become no longer
subject to section 112 emission standards. The EPA also agrees that the
objecting commenter fails to appreciate the added confidence in the
process afforded by the use of title V permitting procedures. Nothing
in section 112(c)(9) of the CAA directs EPA to impose any further
substantive or procedural requirements on sources in source categories
or subcategories that are delisted. Under the CAA, such sources may
permissibly be released from all obligations under section 112(d) of
the CAA with respect to control of HAP emissions. Moreover, in
determining whether an individual source is a member of one source
category versus another subcategory, even while one is listed and
subject to section 112(d) standards and the other is not, nothing in
the CAA requires EPA to subject that decision to notice and comment
rulemaking or to federally establish directly enforceable requirements.
Given that, EPA could have theoretically adopted an approach that
relies upon source and EPA application of the appendix B to subpart
DDDD criteria for determining eligibility for the low-risk subcategory
that, upon EPA approval of a source's LRD, subsequently releases the
source from any further obligations related to the PCWP NESHAP.
However, in order to better ensure that low-risk PCWP sources remain
low risk following the factual findings necessary to approve their LRD,
EPA chose to further require (and sources have accepted) significant
continuing conditions, the failure to meet which will result in low-
risk sources having to return to the PCWP MACT category. The best
mechanism for imposing these conditions is the title V permit process,
which can be used to establish as binding enforceable requirements
terms and conditions that do not otherwise exist as CAA applicable
requirements. The EPA has long held that the title V process can be
used to establish enforceable limitations on the potential to emit air
pollution, for example, in Indian country where there may otherwise be
an absence of regulatory controls. Moreover, EPA's title V regulations
have long provided for what types of permit modifications must occur to
specifically accommodate changes that ``establish or change a permit
term or condition for which there is no underlying applicable
requirement and that the source has assumed to avoid an applicable
requirement to which the source would otherwise be subject.'' See 40
CFR 70.7(e)(2)(i)(A)(4). In the low-risk PCWP context, we believe that
this authority is directly applicable to this situation where we are
conditioning a source's continuing low-risk eligibility upon its
assumption of enforceable terms and conditions reflecting its low-risk
parameters, taken in order to avoid the
[[Page 8363]]
PCWP MACT requirements that would otherwise apply. As a policy matter,
we believe this provides far better assurance that low-risk sources
will remain so than would merely releasing them from all further
obligations with respect to the NESHAP, and in light of the language of
our title V regulations, we cannot accept the objecting commenter's
view that imposing these conditions is not legally permissible.
Turning to the objecting commenter's specific complaints, we
therefore disagree that the process attempts to create specific and
federally enforceable requirements without notice and comment
rulemaking through an informal approval process between the source and
EPA. The process that occurs between the source and EPA is limited to
EPA's review and approval or disapproval of the source's LRD submitted
in support of its applicability determination request, and EPA's
forwarding of approved low-risk parameters to the State permitting
authority. The State's subsequent conversion of those parameters into
enforceable terms and conditions is very much a notice and comment
process.
Regarding the objection that the legal requirements for sources to
maintain low-risk eligibility imposes those legal requirements on
States and the public, it is, of course, under the principles of
federalism embodied in the CAA, always within the States' legal rights
to require a more stringent emission limitation for any PCWP source
than is otherwise required by our rule, including requiring any low-
risk PCWP source to meet MACT. See CAA section 116. In terms of
burdening the public, presumably in having to participate in the title
V permitting process (should the member of the public so choose), it is
not apparent what alternative the objecting commenter would prefer. We
assume that the commenter would not have us, for example, revise our
title V rules to allow these changes to occur without the opportunity
for public comment. We disagree that the process provides no meaningful
opportunity to comment on low-risk parameters or their subsequent
incorporation as terms and conditions in permits. First, EPA's approval
of a source's LRD is a judicially reviewable final action under CAA
section 307(b), as is any applicability determination under CAA section
112. Second, to provide better assurance that sources remain low risk
than is absolutely required under CAA section 112(c)(9), we are
requiring that the notice and comment permit issuance process be used
to implement this need for assurance.
The EPA wishes to clarify the characterization of the low-risk
parameters that result from the LRD approval process, especially in
comparison to our recently finalized reconsideration and amendments of
the Boilers/Process Heaters rule. In the Boilers/Process Heaters rule,
in response to comments, we explained that the more appropriate title V
regulation references of authority for incorporating the section
112(d)(4) compliance option are Sec. 70.7(e)(2)(i)(A)(3), regarding
establishment or changes of case-by-case determinations of an emission
limitation or other standard, and Sec. Sec. 70.7(f) and (g), regarding
permit reopenings to incorporate new applicable requirements. This is
because, unlike in the PCWP context, in the Boilers/Process Heaters
rule, a source's choice of the risk-based compliance option is an
alternative standard and an ``applicable requirement'' in the same
manner as the MACT-based emission limitations in the Boilers/Process
Heaters rule. However, in the PCWP context, prior to a source's
obtaining a title V permit that reflects its EPA-approved low-risk
parameters, the only enforceable applicable requirements relating to
the PCWP NESHAP are the MACT standards themselves, as there is no
alternative health-based compliance option within the standard itself.
Rather, by the nature of the section 112(c)(9) delisting and exemption,
a low-risk PCWP source assumes enforceable terms and conditions only
through the title V permit process, taken as a condition for their
continuing eligibility in the subcategory and avoidance of the PCWP
MACT to which they would otherwise be subject. Therefore, for the PCWP
low-risk subcategory, we continue to regard 40 CFR 70.7(e)(2)(i)(A)(4)
as the relevant ``gatekeeper'' requiring changes to title V permits
incorporating low-risk parameters to be made through the significant
permit revision process. Moreover, since the low-risk parameters sent
from EPA to State permitting authorities are not directly enforceable
``applicable requirements,'' unlike in the Boilers/Process Heaters
rule, we do not regard the permit reopening provisions of 40 CFR
70.7(f) and (g) as being relevant. While, of course, under CAA section
112(c)(9) EPA could have chosen the statutorily permitted option of
requiring no creation of enforceable terms and conditions at all
following approval of a source's LRD, we have chosen to require the
extra step of a process that is closer to that for other programs that
apply to source efforts to limit the potential to emit. While the
objecting commenter is dissatisfied that the process is not identical
to those for Prevention of Significant Deterioration (PSD) or New
Source Review (NSR), which both involve creation of enforceable
requirements in preconstruction permits before they are incorporated
into title V permits, we are frankly surprised that the commenter does
not appear to appreciate the extra assurance we have obtained in
requiring approved low-risk sources, notwithstanding their exemption
from section 112(d) standards, to assume enforceable terms and
conditions even though such is not required under section 112(c)(9).
Regarding the objecting commenter's points about the potential
expiration of permits and the function of the title V ``permit
shield,'' we do not regard these arguments as being valid reasons to
choose to abandon title V as an implementation tool for the low risk
approach, particularly since the logical alternative and clearest way
to avoid the problems raised by the commenter is to require nothing
further of low-risk PCWP sources once EPA approves their LRD and
determines they are eligible for the delisted low-risk subcategory. In
any case, once the source is in the subcategory, the section 112(d)
standard no longer applies to the source and therefore a permit's
expiration or the existence of its permit shield poses no potential
conflict with the PCWP NESHAP. Instead, in order to ensure that it
validly remains in the delisted low-risk subcategory, it is imperative
on the source to ensure that it maintains a valid title V permit
reflecting its low-risk parameters; otherwise it will fail to maintain
low-risk eligibility and will have to comply with MACT.
M. Timing of Title V Permit Revisions
Comment: One commenter strongly supported EPA's proposal to require
only the submittal of a facility's low-risk parameters to its
permitting authority for incorporation into its title V permit (as
opposed to having the title V permit revisions actually incorporated
into the permit). The commenter stated that sources do not have any
control over the amount of time that it takes for State permitting
authorities to review and act upon requests for permit modifications.
In addition, the commenter noted that this approach is consistent with
the permit application shield provision of part 70 and the Boilers/
Process Heaters rule's health-based compliance alternatives. The
commenter also noted that the source is entirely responsible for
ensuring that it remains in compliance with the relevant operating
[[Page 8364]]
parameters that are to be included in the title V permit, even before
that permit is issued.
Two commenters disagreed with the proposal to allow facilities to
qualify for the low-risk subcategory merely based upon submission of a
title V permit revision application. Both commenters stated that EPA's
approach violates title V, the part 70/71 regulations, and
corresponding State laws. The commenters noted that many existing
facilities subject to the PCWP MACT already will have permit terms and
conditions subjecting the entire facility to the standard as a result
of earlier permit revisions or renewals. The commenters stated that
until the title V permits are revised to incorporate enforceable
conditions into permits, sources must remain subject to the MACT
standard. The commenters believe allowing a facility to become part of
the low-risk subcategory before the State or local permitting authority
approves the necessary permit revision undermines the role of the
permitting authorities. The commenters also argued that the proposal
makes the significant permit modification process and public
participation meaningless.
Response: The EPA believes that the objecting commenters are
confusing the EPA's role in reviewing LRD and determining source
eligibility to join the low-risk subcategory with the State permitting
authority's role in making sure permits currently reflect applicable
requirements. We are providing greater assurance than is strictly
required by CAA section 112(c)(9) that sources will remain low risk
following EPA LRD approval. We are requiring that sources timely submit
permit revision applications that reflect their low-risk parameters for
future incorporation as enforceable terms and conditions. We believe
this requirement will help ensure that such sources continue to operate
under the conditions that proved them to be low risk. In cases where a
PCWP source's permit already reflects the PCWP MACT requirements and
the MACT compliance deadline has passed, of course, timely amendment of
the permit itself will be needed in order to allow the source to
alternatively operate according to its low-risk parameters. Until the
permit is actually revised, the source will have to comply with its
then-applicable terms and conditions, even if they reflect MACT and the
source's LRD has been approved by EPA. But we do not regard this
practical problem as being sufficiently severe to merit abandoning the
additional assurance requirement entirely, or even being one that
sources and title V permitting authorities may commonly face when
permit terms become obsolete in the face of new applicable
requirements.
Comment: Two commenters argued that State and local permitting
authorities have the right to thoroughly review and disapprove LRD if
they are incomplete or incorrect. However, the final rule does not
clearly specify that State and local permitting authorities have this
right, and it does not specify that a source must comply with the
emission limits and requirements of the NESHAP if the demonstration is
not approved by the State and local authority. The commenters noted
that without reviewing the LRD, a State or local agency would be unable
to defend granting an exemption to a facility during a public review
process. The commenters noted that many State and local agencies will
find it necessary to review the risk-based exemptions, and the process
could place a very intensive resource demand on State and local air
agencies that must verify extensive emissions and stack information and
review the risk assessments to ensure that they have been done
properly. The review of these risk assessments would require expertise
in risk assessment methodology that State and local agencies may not
possess.
Response: We acknowledge that review of the eligibility
demonstrations for the delisted low-risk subcategory would require
resources for verification of information and may require expertise in
risk assessment methodology that is not yet available in some States.
To alleviate these concerns, we will review and approve/disapprove the
low-risk subcategory eligibility demonstrations submitted by PCWP
facilities. The burden to States of assuring that affected sources
continue to be low-risk will be no more than the burden associated with
ongoing title V enforcement because the parameters that define a source
as low-risk will be reflected in terms and conditions to be
incorporated into the title V permit.
Notwithstanding an EPA finding that a source is eligible for
inclusion in the low-risk subcategory, States are free, consistent with
CAA section 116, to impose more stringent limitations on a low-risk
source, including the requirements of this PCWP NESHAP that would
otherwise apply if the source had not been found to be low risk. These
requirements can be imposed on a State-devised schedule, and might even
include provisions for independent State review and approval of LRD.
The State might determine whether technical problems suggest that the
source may not in fact be low risk, notwithstanding EPA's approval of
the source's LRD. However, under the final rule, unless a State chooses
to involve itself in the decision of whether a source is low risk, EPA
approval of an LRD and the source's submission of a permit revision
application are sufficient for the source to join the low-risk
subcategory. In order to avoid an over-burdening of State resources, we
have maintained the approach that relies upon EPA review and approval
of LRD, and we depend upon States' inherent authority to require more
of themselves and of sources, under CAA section 116, for those States
that choose to do so.
Comment: One commenter stated that there is a possibility that in
some cases, EPA's LRD approval action will be too late for a facility
to submit its title V application before the MACT compliance deadline.
The commenter requested that a facility be allowed to submit its title
V application incorporating the emission rate and process limitations
stated in the LRD concurrent with or soon after the submittal of the
LRD to EPA.
Response: We disagree that the approach suggested by the commenter
is appropriate. In the case of any LRD, we expect there will be the
need to provide additional information or to correct aspects in initial
submissions, and we do not think it is reasonable for permit
applications to be based on these unreviewed, uncorrected LRD,
especially since submission of a permit application starts a clock
under State title V programs with a deadline for the permitting
authority's action. While the problem identified by the commenter may
prove to be a real one in specific cases, we have generally determined
that the best way to ensure that low-risk sources remain low risk and
that terms and conditions accurately reflect their status is to require
that permit revision applications reflect EPA-approved LRD. Thus, it is
important that sources submit their LRD sufficiently early to EPA so
that ``last-minute'' review does not jeopardize the source's chances of
becoming a low-risk source before the MACT compliance deadline, if that
is the source's goal. Of course, in light of our other changes that
extend the MACT compliance deadline and allow sources to become low
risk after the MACT compliance deadline passes, we consider this
problem to not be as severe as suggested by the commenter.
N. Permit Conditions
Comment: Two commenters requested that the number of parameters to
be included in title V permits for low-risk sources be minimized to
allow operational flexibility. One commenter stated that section 11(b)
of appendix B
[[Page 8365]]
to subpart DDDD should ensure that the low-risk requirements continue
to be met, but not impose cumbersome monitoring, recordkeeping, and
reporting requirements with little environmental benefit. In
particular, the commenter is concerned that the list of dispersion
modeling parameters (such as stack height, stack temperature, and stack
flow) can change without changing the overall conclusion of a risk
analysis. The commenter stated that if parameters are too specific,
every change to one of those parameters would require a revision to the
site-specific risk assessment and a title V permit action before the
source has regulatory permission to make the change. The commenter
recommended that only conditions that refer to the health effects
criteria established in appendix B to subpart DDDD be included.
Another commenter requested that EPA clarify that permits primarily
should specify an emission limit and should restrict production rates
only to the extent that they impact the plant's emission limit. The
commenter noted that facilities will attempt to achieve highest
production rates in combination with worst-case operating parameters
during testing, but in practice, it can be difficult to reach worst-
case conditions. The commenter stated that EPA should clarify that
facilities can extrapolate the production rates and operating
conditions measured during performance tests to ``true'' worst-case
emissions scenarios for purposes of their operating permit limits.
Response: Our intent is that parameters incorporated as limits into
a source's title V permit will be those parameters that determine the
source's risk level. This will ensure that sources in the low-risk
subcategory continue to operate in a manner that is consistent with
their LRD. The results of a risk assessment for a particular source
depend on many factors, including the emission rates and dispersion
parameters associated with each process unit at the facility. Process
unit emission rates are a function of production rate and the
effectiveness of any emissions controls used. Process unit emission
rates can also be impacted by other process-related parameters (e.g.,
process unit operating temperature, dryer firing method, fuel type,
wood type, resin HAP content, etc.), but the effect of these parameters
on emission rate is not as well defined as that of production rate and
control system effectiveness. Therefore, we disagree with the notion of
simply extrapolating emission rates based on process-related parameters
other than production rate. However, we agree that emission rates can
be reported in terms of production (i.e., as emission factors) and that
production rate can be used to extrapolate to worst-case emission rates
(provided that all other worst-case conditions remain the same as
during the emissions test). The language in appendix B to subpart DDDD
does not prevent such scaling of emission rates to account for
increased production.
We maintain that production rate and other indicators of emission
rate should be incorporated as limits into title V permits. This is
because the requirement to memorialize the low-risk parameters as
enforceable title V permit terms and conditions is a condition, under
our rule, for eligibility in the low-risk PCWP subcategory established
under CAA section 112(c)(1) and delisted under section 112(c)(9). Thus,
while the effect of the determination that a source is low risk is to
exempt it from other section 112 requirements, the requirement to
assume title V permit conditions to maintain low-risk status is itself
based on our implementation of section 112(c), and is a necessary
condition a source must satisfy as an eligibility criterion for joining
the low-risk subcategory. Sources that fail to meet this condition
cannot maintain low-risk eligibility.
Appendix B to subpart DDDD does not require continuous measurement
of process unit emission rates. Therefore, indicators of process unit
emission rate must be documented on an ongoing basis to provide
assurance that the actual emission rates used to establish the source
as a member of the low-risk subcategory have not changed. Indicators of
emission rate include process unit throughput, control device operating
parameters (monitored as required in section 5(e) of appendix B) if a
control device is used, and other pertinent process unit operational
parameters depending on the type of process unit. These indicators of
emission rate are appropriate title V permit conditions because, during
an inspection, permitting authorities can readily monitor indicators of
emission rate but cannot easily measure actual source emissions.
Therefore, prior to increasing production rate above the level in a
source's permit (or deviating from other permit conditions in a way
that could result in HAP emissions above the levels used to establish a
source as a member of the low-risk subcategory), that source must
revisit its LRD and demonstrate that it continues to qualify for the
low-risk subcategory at the higher production rate.
In addition, because our goal is to ensure that risks posed by a
facility are maintained at a level at or below those in the facility's
LRD, it is also necessary to include certain dispersion parameters as
title V permit conditions. Stack height is an important dispersion
parameter for the risk demonstration and should be included as a permit
condition. If stack height is already incorporated into the title V
permit independent of the LRD, then this parameter should be linked
explicitly to the LRD so that stacks cannot be modified without
revisiting the demonstration. We have also included stack height in
section 11(b) of appendix B to ensure it is included as a permit
condition for those facilities that do not already have stack height
incorporated into their title V permits. We agree that it is not
necessary to include stack temperature and exhaust flow rate as title V
permit conditions because these parameters are not likely to change
considerably in a way that would increase risks without an associated
change in other parameters for which title V permit limits will be
established (i.e., process throughput, control device operating
conditions if a control device is used, or other pertinent process
conditions).
We believe appendix B to subpart DDDD already allows operational
flexibility while ensuring that sources operate in a manner that is
consistent with their LRD. For example, appendix B to subpart DDDD does
not include any process unit parameter monitoring, reporting, or
recordkeeping requirements. Thus, monitoring, recordkeeping, and
reporting requirements must be developed by a permitting authority and
then incorporated into a facility's title V permit in order to ensure a
facility's compliance with its LRD. Additionally, the requirement that
the LRD be based on worst-case operating conditions provides facilities
with operational flexibility because if a source meets our low-risk
requirements while operating under worst-case conditions, then the
source should also meet those criteria when operating under any other
conditions. Finally, section 5(h) of appendix B clarifies that
facilities can use emission rates in their LRD that are more
conservative than worst-case conditions in order to further increase
their operational flexibility.
O. Costs and Benefits of Establishing a Low-Risk Subcategory
Comment: One commenter stated that EPA should revise the cost-
benefit analysis to accurately reflect the lack of public health
protection resulting from the low-risk subcategory. Another commenter
charged that EPA's own data
[[Page 8366]]
reveal that the risk-based exemptions in the final PCWP rule have a
substantially higher net social cost than a lawful MACT standard
without the exemptions, and also result in significantly higher
emissions of HAP, volatile organic compounds (VOC) and PM than a rule
without exemptions. The commenter noted that the preamble to the rule
admitted that the exemptions could increase HAP emissions by 4,400 tons
per year (tpy), when compared to requiring all plants to meet pollution
control requirements. The preamble also acknowledged that exposure to
the HAP released by the PCWP industry have been linked to extensive
noncancer health effects but the Regulatory Impact Analysis (RIA) for
the final rule did not assign an economic value to these very serious
health impacts.
The commenter stated that the Office of Management and Budget (OMB)
has recognized and published estimates of the cost to the public health
associated with exposure to each ton of PM or VOC, but EPA did not
attempt to quantify the public health costs associated with higher
increases of these pollutants. The commenter stated that even using the
lowest end of the monetized benefits published by OMB, the value of
reducing VOC and PM emissions from all PCWP plants exceeds the savings
to industry under the exemptions in the final rule.
The commenter noted that EPA estimated that requiring all PCWP
plants to reduce HAP would result in incidental increases in nitrogen
oxide (NOX) emissions, but EPA made no attempt to compare
this potential increase to the additional emissions of HAP, VOC, and PM
that would result from the exemptions. The available evidence suggests
that the NOX increases are relatively trivial, especially
when compared to the additional pollution authorized by the rule's
exemptions. Nitrogen oxide is a pollutant of concern because it is a
precursor in the formation of ground-level ozone. But the exemptions
that EPA has adopted could increase emissions of VOC (another critical
ozone precursor) by as much as an estimated 13,000 tpy. Arbitrarily,
neither the RIA nor the preamble explains why increasing VOC by 13,000
tpy to avoid 1,200 tpy of NOX would yield a net benefit in
reducing ozone formation.
Similarly, the Final RIA notes that NOX can form fine
PM, but the exemptions in the rule actually could result in an increase
in PM of 6,100 tpy. Based on their calculations using OMB cost-benefit
values, the commenter contended that the reduction in NOX
emissions does reduce public health costs, but the increase in VOC and
PM emissions results in an increase in public health costs anywhere
from 44 to 414 times higher than the public health savings from the
NOX reductions from the exemptions.
In addition, the commenter cited internal EPA documents and stated
that the decision to include risk-based exemptions appears to have been
driven by the desire to lower the cost of the rule, which contradicts
the ruling in National Lime Assn v. EPA, 233 F.3d 625, 640 (D.C. Cir.
2000) that cost may only be taken into account when considering beyond-
the-floor emissions limitations.
Other commenters disagreed and believe there is little sense in
requiring a facility to undertake costly control expenditures when it
does not pose a significant risk to human health or the environment.
One commenter disagreed that the increased HAP emissions resulting from
the low-risk subcategory will impose significant risks on the general
public because, by definition, a source cannot qualify for the low-risk
subcategory unless it does not impose any meaningful risks on the
general public.
The commenter also disagreed with the petitioners' claim that EPA
should have quantified the potential health benefits of the collateral
VOC and PM reductions that would have resulted if low-risk sources were
required to install controls. The commenter argued that while there may
be health benefits to reducing PM or VOC, to the extent that reductions
in these criteria air pollutants are needed, the proper vehicle is
title I of the CAA, not through a title III HAP regulation. The
commenter believes it is improper to justify HAP regulation under title
III solely by the fact that there may be incidental benefits from
criteria pollutant reductions.
The commenter stated that the costs of the rule outweighed the
benefits for low-risk sources. According to the commenter, the
incinerator controls that would be necessary in most cases to meet the
rule would cause increased energy demand and a sharp increase in the
annual emissions of some criteria pollutants from facilities. The
commenter disagreed with the petitioners' claim that increased
NOX emissions are outweighed by the reductions in VOC. The
commenter stated that most PCWP facilities are in NOX-
limited areas, such that any increase in NOX has the
potential to increase ozone formation, whereas emissions of VOC do not.
The commenter also disagreed with the petitioners' argument that
EPA's evaluation of costs and benefits in analyzing whether to
implement the low-risk subcategory ``runs afoul of National Lime Ass'n
v. EPA, 233 F.3d 625, 640 (D.C. Cir. 2000),'' which held that costs may
be considered only when setting ``above the floor standards.'' The
commenter noted that the Court's decision in that case was made solely
with reference to CAA section 112(d), and EPA here has created a
subcategory pursuant to 112(c)(1) and delisted it pursuant to CAA
section 112(c)(9).
Response: In the RIA for the final rule, we quantified the social
costs of the final standard but did not quantify the change in social
costs that would result from application of the low-risk subcategory.
Based on the results of economic impact analyses for other MACT
standards in general, it is likely that the change in social costs (in
this case, without an estimate of benefits) is approximated by the $66
million reduction in compliance costs that is estimated in the
supporting information for the final rule and mentioned in Appendix A
of the RIA. All assumptions underlying emissions estimates related to
the low-risk subcategory are found in the supporting information for
the final rule.
We explain in Chapter 6 of the RIA that we did not provide a
monetized value for the benefits from reduced health effects from HAP
reductions associated with the final rule due to a lack of sufficient
scientific data. The state of science in this area is still in that
position today. Use of a benefit transfer approach as suggested by
commenters is not appropriate in this case. We are continuing our
analytical work to address the uncertainty in a benefits transfer
approach. We did not provide estimates of the monetized benefits
associated with the VOC emission reductions since we did not have
sufficient air quality modeling runs available to allow us to estimate
these benefits and because we did not have sufficient scientific data
to place a monetized benefit value on these reductions. The OMB has
prepared benefits estimates for VOC emission reductions in its annual
Thompson Reports (reports on benefits and costs of Federal Agency
regulations), but these estimates represent broad, general estimates of
the monetized value for these reductions and not benefits of VOC
emission reductions from sources affected by this final rule. This same
point regarding the generalized foundation upon which the Thompson
Report estimates rest may be made for our not providing monetized
benefits for
[[Page 8367]]
the fine PM emission reductions. For the same reasons we did not
estimate monetized benefits for the rule, we did not estimate monetized
disbenefits associated with the low-risk subcategory (e.g., additional
NOX emissions associated with RTO operations): A lack of
sufficient scientific data to assign a monetized benefits value for HAP
reductions, a lack of sufficient air quality modeling runs and
sufficient scientific data to assign a monetized benefits value for VOC
reductions, and the generalized foundation upon which the Thompson
Report estimates are based for PM reductions.
It should be noted that we could only consider HAP emissions in
setting the final standards as per the requirements of CAA section 112.
Quantification of benefits and disbenefits are requested in OMB's RIA
guidelines but are not legally required information for setting MACT
standards.
We disagree with the assertion that our consideration of costs, in
the context of establishing and delisting the low-risk PCWP
subcategory, violates the DC Circuit's decision in National Lime. In
setting the MACT floors for the PCWP NESHAP, cost was not a factor, and
costs of compliance may not be used under the PCWP NESHAP as a basis
for avoiding MACT, if it otherwise applies. Sources will be able to
avoid MACT only if they demonstrate that they are in fact low risk.
There is nothing improper about our general desire to reduce costs of
CAA compliance, where appropriate and where imposing those costs is not
necessary. In fact, the very existence of CAA section 112(c)(9)
reflects the basic congressional goal of avoiding imposing regulatory
burden where that burden is not needed to provide an ample margin of
safety to protect public health.
III. Responses to Comments on the Proposed Amendments and
Clarifications for Subpart DDDD
A. Definitions
1. Dryer Definitions
Comment: One commenter stated that the definition of ``tube dryer''
should be amended to differentiate tube dryers from pneumatic conveyors
that use conditioned air. The commenter provided a suggested revised
definition of ``tube dryer.''
Response: We did not intend to include pneumatic fiber transport
systems under subpart DDDD. Pneumatic fiber transport systems are
distinguished from primary and secondary tube dryers because heat is
added to dryers specifically to remove moisture while the purpose of
the higher temperatures used in fiber transport systems is to prevent
cooling. Therefore, we have amended the definition of ``tube dryer'' as
requested to ensure that pneumatic fiber transport systems are not
classified as tube dryers.
Comment: One commenter requested that EPA modify all of the dryer
definitions in subpart DDDD and appendix B to subpart DDDD by replacing
``at elevated temperature'' with ``by applying heat.''
Response: We agree with the commenter's suggested changes to the
dryer definitions to clarify that heat is deliberately applied during
drying processes. The final rule has been amended as requested by the
commenter.
2. Affected Source and Direct-Fired Process Unit
Comment: One commenter requested that EPA consider modifications to
the proposed amendments to the definitions of ``combustion unit'' and
``affected source.'' First, the definition of ``combustion unit''
should be modified (1) to include combustion units that direct-fire
PCWP process units but are not used to combust HAP emissions, and (2)
for consistency with broad references in the proposed amendments that
define the source category. Alternatively, the commenter suggested a
revision to the proposed amendment to the definition of ``affected
source.''
Second, the use of the word ``directly'' in the definition of
``direct-fired process unit'' could exclude process heaters that
indirectly heat a heat transfer media before the combustion exhaust is
routed to the drying operation, where the remaining heat energy is used
in direct-fire contact with the process material. The commenter stated
that deleting the word ``directly'' from the definition of ``direct-
fired process unit'' would not change the meaning of the definition
because it would still include the phrase ``* * * such that the process
material is contacted by the combustion exhaust.''
Response: After reviewing how the term ``combustion unit'' is used
throughout subpart DDDD, we agree with the commenter's suggested
amendment to the definition to ``combustion unit'' to clarify that
combustion units can be used to direct-fire process units or to control
process exhaust. The amended definition of ``affected source'' (which
we are amending as proposed with no further revisions) includes only
those combustion unit exhaust streams that direct-fire process units,
and it should not be read to mean that all combustion units at the
plant site are part of the PCWP affected source (and thereby exempt
from the Boiler/Process Heaters rule). We also agree with the commenter
that an exhaust stream that supplies indirect heat for other uses would
be part of the PCWP affected source if it is eventually routed through
the direct-fired dryers such that it too contacts the wood material and
becomes a mixture of combustion gases and process gases. We have
amended the definition of ``direct-fired process unit'' accordingly as
suggested by the commenter. However, if the indirect heat exhaust
stream does not routinely pass through the direct-fired dryers, then
this exhaust stream would be subject to the final Boilers/Process
Heaters rule.
3. Engineered Wood Products
Comment: One commenter requested several edits to the definition of
``engineered wood product.'' First, the commenter stated that the type
of resin or glue and the designed use of the product should not be
specified for consistency with the definitions for the other wood
products. Second, the list of products should include parallel strand
lumber. Although implicit in the rule since the definition of
``laminated veneer lumber'' includes parallel strand lumber, parallel
strand lumber is the more commonly used term.
Response: We agree with the commenter that, for consistency with
other definitions in subpart DDDD, the definition of ``engineered wood
products'' need not mention specific resin types or the designed use of
the products. We have also removed the reference to glue from the
commenter's suggested definition because ``resin'' is defined elsewhere
in subpart DDDD, and the definition of ``resin'' includes ``glue.'' We
have also added the term ``parallel strand lumber'' to the definition
of ``engineered wood products.'' Finally, we have revised the
definition of ``laminated veneer lumber'' and added a new definition of
``parallel strand lumber'' to indicate that these are two terms for the
same product.
Comment: One commenter requested that the definitions of ``LSL
press'' and ``LVL press'' be revised to clarify that the material
exiting these presses is a billet that must be sawn into LVL, LSL, or
PSL and that not all LVL presses are heated. The commenter provided
suggested revisions to these definitions.
Response: We agree with the commenter that LSL and LVL presses form
billets that are subsequently cut into LSL and LVL products and amended
the definitions to reflect that clarification. We further edited the
definition of ``LVL press'' to more explicitly include PSL.
[[Page 8368]]
B. Applicability of the PCWP Rule to Lumber Kilns Drying Utility Poles
Comment: One commenter expressed support for EPA's proposal to
expand the definition of lumber dry kilns to include kilns used to dry
utility poles, and two commenters suggested definitions of ``lumber.''
Response: We requested both comments and additional data to either
support or refute the treatment of kilns used to dry utility poles as
lumber kilns subject to subpart DDDD, and we received one supporting
comment and no additional data on this subject. Therefore, we have
concluded that lumber kilns drying utility poles are subject to the
rule (but have no control or work practice requirements), and we have
added a definition of ``lumber'' to Sec. 63.2292 based on commenters'
suggestions.
C. Capture Efficiency Determination
Comment: One commenter had previously requested clarification from
EPA regarding the use of the capture efficiency value and measuring
capture efficiency on unenclosed, uncontrolled presses. The commenter
supported EPA's adoption of the proposed amendment for line 10 of both
table 4 to subpart DDDD and table 2B to appendix B to subpart DDDD but
questioned how to handle fugitive emissions from a press enclosure or
board cooler, which is important when using a partial enclosure to meet
the low-risk criteria.
The commenter also stated that EPA should improve the consistency
throughout the rule regarding emission rate determinations whether a
press or cooler has a control device on it or not. The commenter stated
that regardless of whether a control device is used, facilities should
be allowed to use either the design specifications included in the
definition of ``wood products enclosure'' or determine the percent
capture efficiency of the enclosure to meet any of the compliance
options and/or the LRD. The commenter requested that Lines 9 and 10 of
both table 4 to subpart DDDD and table 2B to appendix B to subpart DDDD
be combined into a single line with no distinction regarding whether
emissions are treated in an add-on control device.
Response: The reconstituted wood products production-based
compliance option (PBCO) applies only to uncontrolled presses. When
determining compliance with the PBCO, it is necessary to compare total
press emissions to the PBCO limit. The total press emissions include
press emissions discharged through the press vents plus any emissions
that are not collected by the press vents but are discharged elsewhere.
To determine the percentage of press emissions discharged through the
press vents, it is necessary to measure capture efficiency and
emissions from the press vents. Then total press (or board cooler)
emissions are determined as follows for comparison to the PBCO limit:
Total press emissions (lb/MSF \3/4\) = measured emissions
(lb/MSF \3/4\)/capture efficiency.
Reconstituted wood products press emissions discharged through
press vents and press emissions discharged elsewhere (e.g., fugitive
emissions) are part of the emissions from a PCWP affected source, and
therefore, must be included in the LRD for the affected source. The
portion of the emissions discharged through the press vents (measured
emissions) can be modeled in the LRD as a point source. The capture
efficiency of the press must be measured, and then the portion of press
emissions that are to be modeled as a fugitive source can be calculated
as follows: Fugitive press emissions (lb/hr) = (measured press
emissions (lb/hr)/capture efficiency) - measured press emissions (lb/
hr).
We disagree that the rows of table 4 to subpart DDDD and table 2B
to appendix B to subpart DDDD pertaining to capture determination
should be combined, but we have edited the second row pertaining to
capture efficiency in each of these tables to address the commenter's
concern. By definition, emissions must be routed to a control device in
order for an enclosure to be a wood products enclosure or a Method 204
permanent total enclosure (PTE). The definitions of wood products
enclosure and PTE were written for situations where emissions are
captured and routed to a control device. However, we agree that it
would be reasonable to assume 100 percent capture if a permanent
enclosure is installed such that all the design criteria for a ``wood
products enclosure'' or a PTE are met except for the requirement to
discharge to a control device.
D. Incorporation by Reference of NCASI Method ISS/FP-A105.01
Comment: One commenter supported EPA's proposal the incorporate by
reference NCASI Method ISS/FP-A105.01 as an alternative method for
measuring emissions of acetaldehyde, acrolein, formaldehyde, methanol,
phenol, and propionaldehyde.
Response: Today's final action amends 40 CFR 63.14 by revising
paragraph (f) to incorporate by reference one test method developed by
the National Council of the Paper Industry for Air and Stream
Improvement (NCASI): Method ISS/FP-A105.01, Impinger Source Sampling
Method for Selected Aldehydes, Ketones, and Polar Compounds, December
2005. The method is available from the NCASI, Methods Manual, P.O. Box
133318, Research Triangle Park, NC 27709-3318 or at http://www.ncasi.org.
It is also available from the docket for today's final
action (Docket ID No. EPA-HQ-OAR-2003-0048). This document was approved
for incorporation by reference by the Director of the Federal Register
in accordance with 5 U.S.C. 552(a) and 1 CFR part 51.
IV. Responses to Comments on SSM Issues
Comment: One commenter stated that there are several problems with
the rule's SSM provisions. The provisions unlawfully permit sources to
exceed emissions standards during SSM periods, are internally
conflicting (paragraphs 63.2250(b) and 63.2271(b)), and limit public
availability of sources' SSM plans.
Response: As stated in the notice of reconsideration and in the
proposed amendments, where the PCWP rule's SSM provisions mirror the
SSM provisions in the General Provisions (40 CFR, part 63, subpart A),
EPA will address comments on those provisions in the reconsideration
and amendment process for the General Provisions, unless PCWP sources
are somehow affected differently than other sources. The EPA has
addressed the issue of excess emissions during periods of SSM as part
of the General Provisions rulemaking process as well as in the 2004
PCWP final rule's BID. The issue of public access is addressed in the
2005 General Provisions notice of reconsideration and proposed
amendments (70 FR 43992, July 29, 2005), and it will be further
addressed in the upcoming General Provisions final amendment and
reconsideration notice.
In response to the comment that the final PCWP rule's SSM
provisions are internally conflicting, we note that the recently
proposed amendments to the General Provisions also included amendments
to subpart DDDD. Instead of specifying that sources must demonstrate
that they were acting in accordance with their SSM plan during periods
of SSM, proposed Sec. 63.2271 specifies that sources must demonstrate
that they were acting in accordance with Sec. 63.6(e) of the General
Provisions during an SSM event. Therefore, when the General Provisions
proposed amendments are finalized, most likely
[[Page 8369]]
in the Spring of 2006, there will no longer be any conflict within the
PCWP rule's SSM provisions.
Comment: Two commenters discussed the proposed amendment to Sec.
63.2250(a), the section that describes when the SSM provisions apply.
One commenter mostly supported the proposed amendment but stated that
Sec. 63.2250(a) should not continue to differentiate between scheduled
and unscheduled startups and shutdowns. In addition, the amendment does
not resolve the confusion between scheduled and unscheduled startups
and shutdowns. The commenter stated that although malfunctions can
result in unscheduled startups and shutdowns, many unscheduled startups
and shutdowns are considered to be normal operating practices by the
industry rather than malfunctions. The proposed amendment fails to
accurately clarify EPA's intent as stated in the preamble to the
proposed amendments, and the proposed wording could inadvertently cause
all unscheduled startups and shutdowns to be considered malfunctions.
The commenter stated that the PCWP rule should not treat scheduled
startups and shutdowns any differently from unscheduled startups and
shutdowns.
Another commenter stated that the SSM provisions are overly broad,
and the proposed amendment suggests extending the provisions to
unscheduled startups and shutdowns resulting from malfunction events.
The commenter stated that EPA will only worsen the problems with the
SSM provisions by promulgating this amendment, particularly in cases in
which the equipment ``malfunction'' is not causally linked to any
concurrent pollution exceedance.
Response: We agree with the first commenter that the PCWP NESHAP
should not differentiate between scheduled and unscheduled startups and
shutdowns. The General Provisions do not treat scheduled startups and
shutdowns any differently than unscheduled startups and shutdowns.
Although it was not our intention to exclude unscheduled startups and
shutdowns from Sec. 63.2250(b), we realize that the promulgated
language did appear to exclude them, and our proposed amendment to this
language did not clarify our intent. Therefore, we are removing all
occurrences of ``scheduled'' and ``unscheduled'' from Sec. 63.2250(b).
Sources should refer to Sec. 63.6(e) of the General Provisions for
guidance on complying with the General Provisions during periods of
SSM.
V. Statutory and Executive Order Reviews
A. Executive Order 12866: Regulatory Planning and Review
Under Executive Order 12866 (58 FR 51735, October 4, 1993), EPA
must determine whether the regulatory action is ``significant'' and,
therefore, subject to review by the Office of Management and Budget
(OMB) and the requirements of the Executive Order. The Executive Order
defines ``significant regulatory action'' as one that is likely to
result in a rule that may:
(1) Have an annual effect on the economy of $100 million or more or
adversely affect in a material way the economy, a sector of the
economy, productivity, competition, jobs, the environment, public
health or safety, or State, local, or tribal governments or
communities;
(2) Create a serious inconsistency or otherwise interfere with an
action taken or planned by another agency;
(3) Materially alter the budgetary impact of entitlements, grants,
user fees, or loan programs, or the rights and obligations of
recipients thereof; or
(4) Raise novel legal or policy issues arising out of legal
mandates, the President's priorities, or the principles set forth in
the Executive Order.
Pursuant to the terms of Executive Order 12866, it has been
determined that today's action is a ``significant regulatory action''
because it raises novel legal or policy issues. As such, this action
was submitted to OMB for review under Executive Order 12866. Changes
made in response to OMB suggestions or recommendations are documented
in the public record (see ADDRESSES section of this preamble).
B. Paperwork Reduction Act
This action does not impose any new information collection burden.
We are not promulgating any new paperwork (e.g., monitoring, reporting,
recordkeeping) as part of today's final action. OMB has previously
approved the information collection requirements contained in the final
rule (40 CFR part 63, subpart DDDD) under the provisions of the
Paperwork Reduction Act, 44 U.S.C. 3501, and has assigned OMB control
number 2060-0552, EPA ICR number 1984.02. A copy of the OMB approved
Information Collection Request (ICR) may be obtained from Susan Auby,
Collection Strategies Division; U.S. Environmental Protection Agency
(2822T); 1200 Pennsylvania Ave., NW., Washington, DC 20460 or by
calling (202) 566-1672.
Burden means the total time, effort, or financial resources
expended by persons to generate, maintain, retain, or disclose or
provide information to or for a Federal agency. This includes the time
needed to review instructions; develop, acquire, install, and utilize
technology and systems for the purposes of collecting, validating, and
verifying information, processing and maintaining information, and
disclosing and providing information; adjust the existing ways to
comply with any previously applicable instructions and requirements;
train personnel to be able to respond to a collection of information;
search data sources; complete and review the collection of information;
and transmit or otherwise disclose the information.
An agency may not conduct or sponsor, and a person is not required
to respond to, a collection of information unless it displays a
currently valid OMB control number. The OMB control numbers for EPA's
regulations are listed in 40 CFR part 9 and 48 CFR chapter 15.
C. Regulatory Flexibility Act
The EPA has determined that it is not necessary to prepare a
regulatory flexibility analysis in connection with this final action.
For purposes of assessing the impacts of today's action on small
entities, small entity is defined as: (1) A small business as defined
by the Small Business Administrations' regulations at 13 CFR 121.201;
(2) a small governmental jurisdiction that is a government of a city,
county, town, school district or special district with a population of
less than 50,000; and (3) a small organization that is any not-for-
profit enterprise which is independently owned and operated and is not
dominant in its field.
After considering the economic impacts of today's action on small
entities, EPA has concluded that this action will not have a
significant economic impact on a substantial number of small entities.
In determining whether a rule has a significant economic impact on a
substantial number of small entities, the impact of concern is any
significant adverse economic impact on small entities, since the
primary purpose of the regulatory flexibility analyses is to identify
and address regulatory alternatives ``which minimize any significant
economic impact of the proposed rule on small entities.'' 5 U.S.C.
Sections 603 and 604. Thus, an agency may conclude that a rule will not
have a significant economic impact on a substantial number of small
entities if the rule relieves regulatory burden, or otherwise has a
positive economic effect
[[Page 8370]]
on all of the small entities subject to the rule.
Today's action reduces the number of emissions tests (and costs
associated with these tests) required for facilities to demonstrate
that they are part of the low-risk subcategory, and provides facilities
with additional time to complete the tests and LRD. We have therefore
concluded that today's final rule will relieve regulatory burden for
all small entities.
D. Unfunded Mandates Reform Act
Title II of the Unfunded Mandates Reform Act of 1995 (UMRA), Public
Law 104-4, establishes requirements for Federal agencies to assess the
effects of their regulatory actions on State, local, and tribal
governments and the private sector. Under section 202 of the UMRA, EPA
generally must prepare a written statement, including a cost-benefit
analysis, for proposed and final rules with ``Federal mandates'' that
may result in expenditures by State, local, and tribal governments, in
the aggregate, or by the private sector, of $100 million or more in any
1 year. Before promulgating an EPA rule for which a written statement
is needed, section 205 of the UMRA generally requires EPA to identify
and consider a reasonable number of regulatory alternatives and adopt
the least costly, most cost-effective, or least burdensome alternative
that achieves the objectives of the rule. The provisions of section 205
do not apply when they are inconsistent with applicable law. Moreover,
section 205 allows EPA to adopt an alternative other than the least
costly, most cost-effective, or least burdensome alternative if the
Administrator publishes with the final rule an explanation why that
alternative was not adopted. Before EPA establishes any regulatory
requirements that may significantly or uniquely affect small
governments, including tribal governments, it must have developed,
under section 203 of the UMRA, a small government agency plan. The plan
must provide for notifying potentially affected small governments,
enabling officials of affected small governments to have meaningful and
timely input in the development of EPA's regulatory proposals with
significant Federal intergovernmental mandates, and informing,
educating, and advising small governments on compliance with the
regulatory requirements.
The EPA has determined that today's action does not contain a
Federal mandate that may result in expenditures of $100 million or more
for State, local, and tribal governments, in the aggregate, or the
private sector in any 1 year. Although the final rule had annualized
costs estimated to range from $74 to $140 million (depending on the
number of facilities eventually demonstrating eligibility for the low-
risk category), today's action does not add new requirements that would
increase this cost. Thus, today's action is not subject to the
requirements of sections 202 and 205 of the UMRA. In addition, EPA has
determined that today's action does not significantly or uniquely
affect small governments because it contains no requirements that apply
to such governments or impose obligations upon them. Therefore, today's
action is not subject to the requirements of section 203 of the UMRA.
E. Executive Order 13132: Federalism
Executive Order 13132 (64 FR 43255, August 10, 1999) requires EPA
to develop an accountable process to ensure ``meaningful and timely
input by State and local officials in the development of regulatory
policies that have federalism implications.'' ``Policies that have
federalism implications'' are defined in the Executive Order to include
regulations that have ``substantial direct effects on the States, on
the relationship between the national government and the States, or on
the distribution of power and responsibilities among the various levels
of government.'' Under Executive Order 13132, EPA may not issue a
regulation that has federalism implications, that imposes substantial
direct compliance costs, and that is not required by statute, unless
the Federal government provides the funds necessary to pay the direct
compliance costs incurred by State and local governments, or EPA
consults with State and local officials early in the process of
developing the proposed regulation. The EPA also may not issue a
regulation that has federalism implications and that preempts State law
unless EPA consults with State and local officials early in the process
of developing the proposed regulation.
If EPA complies by consulting, Executive Order 13132 requires EPA
to provide to OMB, in a separately identified section of the preamble
to the rule, a federalism summary impact statement (FSIS). The FSIS
must include a description of the extent of EPA's prior consultation
with State and local officials, a summary of the nature of their
concerns and EPA's position supporting the need to issue the
regulation, and a statement of the extent to which the concerns of
State and local officials have been met. Also, when EPA transmits a
draft final rule with federalism implications to OMB for review
pursuant to Executive Order 12866, it must include a certification from
EPA's Federalism Official stating that EPA has met the requirements of
Executive Order 13132 in a meaningful and timely manner.
Today's action does not have federalism implications. It will not
have substantial direct effects on the States, on the relationship
between the national government and the States, or on the distribution
of power and responsibilities among the various levels of government,
as specified in Executive Order 13132. None of the affected facilities
are owned or operated by State governments, and the requirements
discussed in today's action will not supersede State regulations that
are more stringent. Thus, Executive Order 13132 does not apply to
today's action.
F. Executive Order 13175: Consultation and Coordination With Indian
Tribal Governments
Executive Order 13175 (65 FR 67249, November 6, 2000) requires EPA
to develop an accountable process to ensure ``meaningful and timely
input by tribal officials in the development of regulatory policies
that have tribal implications.'' ``Policies that have tribal
implications'' are defined in the Executive Order to include
regulations that have ``substantial direct effects on one or more
Indian tribes, on the relationship between the Federal government and
the Indian tribes, or on the distribution of power and responsibilities
between the Federal government and Indian tribes.''
Today's action does not have tribal implications. It will not have
substantial direct effects on tribal governments, on the relationship
between the Federal government and Indian tribes, or on the
distribution of power and responsibilities between the Federal
government and Indian tribes, as specified in Executive Order 13175. No
affected facilities are owned or operated by Indian tribal governments.
Thus, Executive Order 13175 does not apply to today's action.
G. Executive Order 13045: Protection of Children From Environmental
Health and Safety Risks
Executive Order 13045 (62 FR 19885, April 23, 1997) applies to any
rule that: (1) Is determined to be ``economically significant'' as
defined under Executive Order 12866, and (2) concerns the environmental
health or safety risk that EPA has reason to believe may have a
disproportionate effect on children. If the regulatory action meets
both criteria, EPA must evaluate the environmental
[[Page 8371]]
health or safety effects of the planned rule on children, and explain
why the planned regulation is preferable to other potentially effective
and reasonably feasible alternatives considered by EPA.
Today's action is not subject to the Executive Order because it is
not ``economically significant'' and EPA does not believe that the
environmental health or safety risks associated with the emissions
addressed by this action present a disproportionate risk to children.
This conclusion is based on two factors. First, the noncancer human
health toxicity values we used in our analysis at promulgation (e.g.,
RfCs) are protective of sensitive subpopulations, including children.
Second, if EPA determines that a chemical addressed by this regulation
has the potential for a disproportionate impact on predicted cancer
risks due to early-life exposure and acts through a mutagenic mode of
action, it is recommended that the risk assessments developed for the
purposes of this regulation employ applicable cancer potency
adjustments as described in EPA's Supplemental Guidance for Assessing
Susceptibility from Early-Life Exposure to Carcinogens. For purposes of
this rulemaking, EPA has not determined that any of the pollutants in
question has the potential for a disproportionate impact on predicted
cancer risks due to early-life exposure.
H. Executive Order 13211: Actions That Significantly Affect Energy
Supply, Distribution, or Use
Today's action is not a ``significant energy action'' as defined in
Executive Order 13211 (66 FR 28355, May 22, 2001) because it is not
likely to have a significant adverse effect on the supply,
distribution, or use of energy. Further, we have concluded that today's
action is not likely to have any adverse energy effects.
I. National Technology Transfer and Advancement Act
Section 12(d) of the National Technology Transfer and Advancement
Act (NTTAA) of 1995 (Pub. L. 104-113; 15 U.S.C. 272 note) directs EPA
to use voluntary consensus standards in its regulatory and procurement
activities unless to do so would be inconsistent with applicable law or
otherwise impractical. Voluntary consensus standards are technical
standards (e.g., materials specifications, test methods, sampling
procedures, business practices) developed or adopted by one or more
voluntary consensus bodies. The NTTAA directs EPA to provide Congress,
through annual reports to OMB, with explanations when an agency does
not use available and applicable voluntary consensus standards.
This action involves two technical standards. In addition to the
standards EPA included in the promulgated rule, the EPA cites the
following standards in today's final amendments: (1) NCASI Method ISS/
FP-A105.01 (12/05), ``Impinger Source Sampling Method for Aldehydes,
Ketones, And Polar Compounds''; and (2) EPA Method 207-A (proposed 12/
8/97 for appendix M to 40 CFR part 51), ``Method for Measuring
Isocyanates in Stationary Source Emissions.''
Consistent with the NTTAA, EPA conducted searches to identify
voluntary consensus standards in addition to these methods. No
applicable voluntary consensus standards were identified for EPA Method
207-A. The search and review results have been documented and are
placed in the docket for the final rule.
One voluntary consensus standard was found that is potentially
applicable to the NCASI method. The German standard VDI 3862 (12/00),
``Gaseous Emission Measurement-Measurement of Aliphatic and Aromatic
Aldehydes and Ketones by 2,4-Dinitrophenyhydrazine (DNPH) Impinger
Method,'' is a good impinger method for the sampling and analysis of
aldehydes and ketones that includes the use of an external standard,
field and analytical blanks, and repeatability tests. However, the VDI
method is missing some key quality assurance/quality control (QA/QC)
procedures that are included in the NCASI method. Specifically, VDI
3862 (12/00) is missing the use of internal standards, matrix spikes,
and surrogate standards in the analytical step, as well as a duplicate
sample run requirement, and sampling train QA/QC samples such as field,
run, and sampling train spikes. Therefore, this VDI method, as written,
is not acceptable as an alternative to the NCASI method for the
purposes of today's rule amendments.
Table 4 to subpart DDDD of 40 CFR part 63 and table 2B to appendix
B to subpart DDDD of 40 CFR part 63 in today's rule amendments list the
testing methods included in the final PCWP NESHAP. Under Sec. Sec.
63.7(f) and 63.8(f) of subpart A of the General Provisions, a source
may apply to EPA for permission to use alternative test methods or
alternative monitoring requirements in place of any required testing
methods, performance specifications, or procedures.
J. Congressional Review Act
The Congressional Review Act, 5 U.S.C. 801 et seq., as added by the
Small Business Regulatory Enforcement Fairness Act of 1996, generally
provides that before a rule may take effect, the agency promulgating
the rule must submit a rule report, which includes a copy of the rule,
to each House of the Congress and to the Comptroller General of the
United States. The EPA will submit a report containing this rule and
other required information to the U.S. Senate, the U.S. House of
Representatives, and the Comptroller General of the United States prior
to publication of the rule in the Federal Register. A major rule cannot
take effect until 60 days after it is published in the Federal
Register. This action is not a ``major rule'' as defined by 5 U.S.C.
804(2). The final rule will be effective February 16, 2006.
List of Subjects for 40 CFR Part 63
Environmental protection, Administrative practice and procedures,
Air pollution control, Hazardous substances, Incorporation by
reference, Intergovernmental relations, Reporting and recordkeeping
requirements.
Dated: January 31, 2006.
Stephen L. Johnson,
Administrator.
0
For the reasons stated in the preamble, title 40, chapter I, part 63 of
the Code of Federal Regulations is amended as follows:
PART 63--[AMENDED]
0
1. The authority citation for part 63 continues to read as follows:
Authority: 42 U.S.C. 7401.
Subpart A--[Amended]
0
2. Section 63.14 is amended by adding paragraph (f)(4) to read as
follows:
Sec. 63.14 Incorporation by reference.
* * * * *
(f) * * *
(4) NCASI Method ISS/FP-A105.01, Impinger Source Sampling Method
for Selected Aldehydes, Ketones, and Polar Compounds, December 2005,
Methods Manual, NCASI, Research Triangle Park, NC, IBR approved for
table 4 to subpart DDDD of this part and appendix B to subpart DDDD of
this part.
* * * * *
Subpart DDDD--National Emission Standards for Hazardous Air
Pollutants: Plywood and Composite Wood Products
0
3. Section 63.2232 is amended by revising paragraph (b) to read as
follows:
[[Page 8372]]
Sec. 63.2232 What parts of my plant does this subpart cover?
* * * * *
(b) The affected source is the collection of dryers, refiners,
blenders, formers, presses, board coolers, and other process units
associated with the manufacturing of plywood and composite wood
products. The affected source includes, but is not limited to, green
end operations, refining, drying operations (including any combustion
unit exhaust stream routinely used to direct fire process unit(s)),
resin preparation, blending and forming operations, pressing and board
cooling operations, and miscellaneous finishing operations (such as
sanding, sawing, patching, edge sealing, and other finishing operations
not subject to other national emission standards for hazardous air
pollutants (NESHAP)). The affected source also includes onsite storage
and preparation of raw materials used in the manufacture of plywood
and/or composite wood products, such as resins; onsite wastewater
treatment operations specifically associated with plywood and composite
wood products manufacturing; and miscellaneous coating operations
(Sec. 63.2292). The affected source includes lumber kilns at PCWP
manufacturing facilities and at any other kind of facility.
* * * * *
0
4. Section 63.2233 is amended by revising paragraphs (b) and (c) to
read as follows:
Sec. 63.2233 When do I have to comply with this subpart?
* * * * *
(b) If you have an existing affected source, you must comply with
the compliance options, operating requirements, and work practice
requirements for existing sources no later than October 1, 2008.
(c) If you have an area source that increases its emissions or its
potential to emit such that it becomes a major source of HAP, you must
be in compliance with this subpart by October 1, 2008 or upon initial
startup of your affected source as a major source, whichever is later.
* * * * *
0
5. Section 63.2250 is amended by revising paragraph (a) to read as
follows:
Sec. 63.2250 What are the general requirements?
(a) You must be in compliance with the compliance options,
operating requirements, and the work practice requirements in this
subpart at all times, except during periods of process unit or control
device startup, shutdown, and malfunction; prior to process unit
initial startup; and during the routine control device maintenance
exemption specified in Sec. 63.2251. The compliance options, operating
requirements, and work practice requirements do not apply during times
when the process unit(s) subject to the compliance options, operating
requirements, and work practice requirements are not operating, or
during periods of startup, shutdown, and malfunction. Startup and
shutdown periods must not exceed the minimum amount of time necessary
for these events.
* * * * *
0
6. Section 63.2252 is added to read as follows:
Sec. 63.2252 What are the requirements for process units that have no
control or work practice requirements?
For process units not subject to the compliance options or work
practice requirements specified in Sec. 63.2240 (including, but not
limited to, lumber kilns), you are not required to comply with the
compliance options, work practice requirements, performance testing,
monitoring, SSM plans, and recordkeeping or reporting requirements of
this subpart, or any other requirements in subpart A of this part,
except for the initial notification requirements in Sec. 63.9(b).
0
7. Section 63.2262 is amended by revising paragraph (d)(1) to read as
follows:
Sec. 63.2262 How do I conduct performance tests and establish
operating requirements?
* * * * *
(d) * * *
(1) Sampling sites must be located at the inlet (if emission
reduction testing or documentation of inlet methanol or formaldehyde
concentration is required) and outlet of the control device (defined in
Sec. 63.2292) and prior to any releases to the atmosphere. For control
sequences with wet control devices (defined in Sec. 63.2292) followed
by control devices (defined in Sec. 63.2292), sampling sites may be
located at the inlet and outlet of the control sequence and prior to
any releases to the atmosphere.
* * * * *
0
8. Section 63.2269 is amended by revising the introductory text of
paragraph (c) to read as follows:
Sec. 63.2269 What are my monitoring installation, operation, and
maintenance requirements?
* * * * *
(c) Wood moisture monitoring. For each furnish or veneer moisture
meter, you must meet the requirements in paragraphs (a)(1) through (3)
and paragraphs (c)(1) through (5) of this section.
* * * * *
0
9. Section 63.2292 is amended by revising the definitions for
``Affected source,'' ``Combustion unit,'' ``Fiberboard mat dryer,''
``Laminated veneer lumber,'' ``Lumber kiln,'' ``Plywood,'' ``Plywood
and composite wood products manufacturing facility,'' ``Press
predryer,'' ``Tube dryer,'' and ``Rotary strand dryer''; and adding
definitions for ``Direct-fired process unit,'' ``Engineered wood
product,'' ``Lumber,'' ``Molded particleboard,'' and ``Parallel strand
lumber'' to read as follows:
Sec. 63.2292 What definitions apply to this subpart?
* * * * *
Affected source means the collection of dryers, refiners, blenders,
formers, presses, board coolers, and other process units associated
with the manufacturing of plywood and composite wood products. The
affected source includes, but is not limited to, green end operations,
refining, drying operations (including any combustion unit exhaust
stream routinely used to direct fire process unit(s)), resin
preparation, blending and forming operations, pressing and board
cooling operations, and miscellaneous finishing operations (such as
sanding, sawing, patching, edge sealing, and other finishing operations
not subject to other NESHAP). The affected source also includes onsite
storage of raw materials used in the manufacture of plywood and/or
composite wood products, such as resins; onsite wastewater treatment
operations specifically associated with plywood and composite wood
products manufacturing; and miscellaneous coating operations (defined
elsewhere in this section). The affected source includes lumber kilns
at PCWP manufacturing facilities and at any other kind of facility.
* * * * *
Combustion unit means a dryer burner, process heater, or boiler.
Combustion units may be used for combustion of organic HAP emissions.
* * * * *
Direct-fired process unit means a process unit that is heated by
the passing of combustion exhaust through the process unit such that
the process material is contacted by the combustion exhaust.
* * * * *
Engineered wood product means a product made with lumber, veneers,
[[Page 8373]]
strands of wood, or from other small wood elements that are bound
together with resin. Engineered wood products include, but are not
limited to, laminated strand lumber, laminated veneer lumber, parallel
strand lumber, wood I-joists, and glue-laminated beams.
* * * * *
Fiberboard mat dryer means a dryer used to reduce the moisture of
wet-formed wood fiber mats by applying heat. A fiberboard mat dryer is
a process unit.
* * * * *
Laminated veneer lumber (LVL) means a composite product formed into
a billet made from layers of resinated wood veneer sheets or pieces
pressed together with the grain of each veneer aligned primarily along
the length of the finished product. Laminated veneer lumber is also
known as parallel strand lumber (PSL).
Lumber means boards or planks sawed or split from logs or timber,
including logs or timber processed for use as utility poles or other
wood components. Lumber can be either green (non-dried) or dried.
Lumber is typically either air-dried or kiln-dried.
Lumber kiln means an enclosed dryer operated by applying heat to
reduce the moisture content of lumber.
* * * * *
Molded particleboard means a shaped composite product (other than a
composite panel) composed primarily of cellulosic materials (usually
wood or agricultural fiber) generally in the form of discrete pieces or
particles, as distinguished from fibers, which are pressed together
with resin.
* * * * *
Parallel strand lumber (PSL) means a composite product formed into
a billet made from layers of resinated wood veneer sheets or pieces
pressed together with the grain of each veneer aligned primarily along
the length of the finished product. Parallel strand lumber is also
known as laminated veneer lumber (LVL).
* * * * *
Plywood means a panel product consisting of layers of wood veneers
hot pressed together with resin. Plywood includes panel products made
by hot pressing (with resin) veneers to a substrate such as
particleboard, medium density fiberboard, or lumber. Plywood products
may be flat or curved.
Plywood and composite wood products (PCWP) manufacturing facility
means a facility that manufactures plywood and/or composite wood
products by bonding wood material (fibers, particles, strands, veneers,
etc.) or agricultural fiber, generally with resin under heat and
pressure, to form a panel, engineered wood product, or other product
defined in Sec. 63.2292. Plywood and composite wood products
manufacturing facilities also include facilities that manufacture dry
veneer and lumber kilns located at any facility. Plywood and composite
wood products include, but are not limited to, plywood, veneer,
particleboard, molded particleboard, oriented strandboard, hardboard,
fiberboard, medium density fiberboard, laminated strand lumber,
laminated veneer lumber, wood I-joists, kiln-dried lumber, and glue-
laminated beams.
Press predryer means a dryer used to reduce the moisture and
elevate the temperature by applying heat to a wet-formed fiber mat
before the mat enters a hot press. A press predryer is a process unit.
* * * * *
Rotary strand dryer means a rotary dryer operated by applying heat
and used to reduce the moisture of wood strands used in the manufacture
of oriented strandboard, laminated strand lumber, or other wood strand-
based products. A rotary strand dryer is a process unit.
* * * * *
Tube dryer means a single-stage or multi-stage dryer operated by
applying heat to reduce the moisture of wood fibers or particles as
they are conveyed (usually pneumatically) through the dryer. Resin may
or may not be applied to the wood material before it enters the tube
dryer. Tube dryers do not include pneumatic fiber transport systems
that use temperature and humidity conditioned pneumatic system supply
air in order to prevent cooling of the wood fiber as it is moved
through the process. A tube dryer is a process unit.
* * * * *
0
10. Table 4 to subpart DDDD of part 63 is revised to read as follows:
Table 4 to Subpart DDDD of Part 63.--Requirements for Performance Tests
------------------------------------------------------------------------
For . . . You must . . . Using . . .
------------------------------------------------------------------------
(1) each process unit select sampling Method 1 or 1A of 40
subject to a compliance port's location and CFR part 60,
option in table 1A or 1B to the number of appendix A (as
this subpart or used in traverse ports. appropriate).
calculation of an emissions
average under Sec.
63.2240(c).
(2) each process unit determine velocity Method 2 in addition
subject to a compliance and volumetric flow to Method 2A, 2C,
option in table 1A or 1B to rate. 2D, 2F, or 2G in
this subpart or used in appendix A to 40
calculation of an emissions CFR part 60 (as
average under Sec. appropriate).
63.2240(c).
(3) each process unit conduct gas Method 3, 3A, or 3B
subject to a compliance molecular weight in appendix A to 40
option in table 1A or 1B to analysis. CFR part 60 (as
this subpart or used in appropriate).
calculation of an emissions
average under Sec.
63.2240(c).
(4) each process unit measure moisture Method 4 in appendix
subject to a compliance content of the A to 40 CFR part
option in table 1A or 1B to stack gas. 60; OR Method 320
this subpart or used in in appendix A to 40
calculation of an emissions CFR part 63; OR
average under Sec. ASTM D6348-03 (IBR,
63.2240(c). see Sec.
63.14(b)).
(5) each process unit measure emissions of Method 25A in
subject to a compliance total HAP as THC. appendix A to 40
option in table 1B to this CFR part 60. You
subpart for which you may measure
choose to demonstrate emissions of
compliance using a total methane using EPA
HAP as THC compliance Method 18 in
option. appendix A to 40
CFR part 60 and
subtract the
methane emissions
from the emissions
of total HAP as
THC.
[[Page 8374]]
(6) each process unit measure emissions of Method 320 in
subject to a compliance total HAP (as appendix A to 40
option in table 1A to this defined in Sec. CFR part 63; OR the
subpart; OR for each 63.2292). NCASI Method IM/CAN/
process unit used in WP-99.02 (IBR, see
calculation of an emissions Sec. 63.14(f));
average under Sec. OR the NCASI Method
63.2240(c). ISS/FP-A105.01
(IBR, see Sec.
63.14(f)); OR ASTM
D6348-03 (IBR, see
Sec. 63.14(b))
provided that
percent R as
determined in Annex
A5 of ASTM D6348-03
is equal or greater
than 70 percent and
less than or equal
to 130 percent.
(7) each process unit measure emissions of Method 308 in
subject to a compliance methanol. appendix A to 40
option in table 1B to this CFR part 63; OR
subpart for which you Method 320 in
choose to demonstrate appendix A to 40
compliance using a methanol CFR part 63; OR the
compliance option. NCASI Method CI/WP-
98.01 (IBR, see
Sec. 63.14(f));
OR the NCASI Method
IM/CAN/WP-99.02
(IBR, see Sec.
63.14(f)); OR the
NCASI Method ISS/FP-
A105.01 (IBR, see
Sec. 63.14(f)).
(8) each process unit measure emissions of Method 316 in
subject to a compliance formaldehyde. appendix A to 40
option in table 1B to this CFR part 63; OR
subpart for which you Method 320 in
choose to demonstrate appendix A to 40
compliance using a CFR part 63; OR
formaldehyde compliance Method 0011 in
option. ``Test Methods for
Evaluating Solid
Waste, Physical/
Chemical Methods''
(EPA Publication
No. SW-846) for
formaldehyde; OR
the NCASI Method CI/
WP-98.01 (IBR, see
Sec. 63.14(f));
OR the NCASI Method
IM/CAN/WP-99.02
(IBR, see Sec.
63.14(f)); OR the
NCASI Method ISS/FP-
A105.01 (IBR, see
Sec. 63.14(f)).
(9) each reconstituted wood meet the design Methods 204 and 204A
product press at a new or specifications through 204F of 40
existing affected source or included in the CFR part 51,
reconstituted wood product definition of wood appendix M, to
board cooler at a new products enclosure determine capture
affected source subject to in Sec. 63.2292; efficiency (except
a compliance option in or for wood products
table 1B to this subpart or determine the enclosures as
used in calculation of an percent capture defined in Sec.
emissions average under efficiency of the 63.2292).
Sec. 63.2240(c). enclosure directing Enclosures that
emissions to an add- meet the definition
on control device. of wood products
enclosure or that
meet Method 204
requirements for a
permanent total
enclosure (PTE) are
assumed to have a
capture efficiency
of 100 percent.
Enclosures that do
not meet either the
PTE requirements or
design criteria for
a wood products
enclosure must
determine the
capture efficiency
by constructing a
TTE according to
the requirements of
Method 204 and
applying Methods
204A through 204F
(as appropriate).
As an alternative
to Methods 204 and
204A through 204F,
you may use the
tracer gas method
contained in
appendix A to this
subpart.
(10) each reconstituted wood determine the a TTE and Methods
product press at a new or percent capture 204 and 204A
existing affected source or efficiency. through 204F (as
reconstituted wood product appropriate) of 40
board cooler at a new CFR part 51,
affected source subject to appendix M. As an
a compliance option in alternative to
table 1A to this subpart. installing a TTE
and using Methods
204 and 204A
through 204F, you
may use the tracer
gas method
contained in
appendix A to this
subpart. Enclosures
that meet the
design criteria (1)
through (4) in the
definition of wood
products enclosure,
or that meet Method
204 requirements
for a PTE (except
for the criteria
specified in
section 6.2 of
Method 204) are
assumed to have a
capture efficiency
of 100 percent.
Measured emissions
divided by the
capture efficiency
provides the
emission rate.
(11) each process unit establish the site- data from the
subject to a compliance specific operating parameter
option in tables 1A and 1B requirements monitoring system
to this subpart or used in (including the or THC CEMS and the
calculation of an emissions parameter limits or applicable
average under Sec. THC concentration performance test
63.2240(c). limits) in table 2 method(s).
to this subpart.
------------------------------------------------------------------------
?>
[[Page 8375]]
Appendix A to Subpart DDDD of Part 63--Alternative Procedure To
Determine Capture Efficiency From Enclosures Around Hot Presses in the
Plywood and Composite Wood Products Industry Using Sulfur Hexafluoride
Tracer Gas
0
11. Revise paragraphs 10.4 and 10.5 of section 10 to read as follows:
10.0 Calibration and Standardization.
* * * * *
10.4 Gas Chromatograph. Follow the pre-test calibration
requirements specified in section 8.5.1.
10.5 Gas Chromatograph for Ambient Sampling (Optional). For the
optional ambient sampling, follow the calibration requirements
specified in section 8.5.1 or ASTM E 260 and E 697 and by the
equipment manufacturer for gas chromatograph measurements.
* * * * *
0
12. Revise appendix B to subpart DDDD to read as follows:
Appendix B to Subpart DDDD of Part 63--Methodology and Criteria for
Demonstrating That an Affected Source Is Part of the Low-risk
Subcategory of Plywood and Composite Wood Products Manufacturing
Affected Sources
1. Purpose
This appendix provides the methodology and criteria for
demonstrating that your affected source is part of the low-risk
subcategory of plywood and composite wood products (PCWP)
manufacturing facilities. You must demonstrate that your affected
source is part of the low-risk subcategory using either a look-up
table analysis (based on the look-up tables included in this
appendix) or using a site-specific risk assessment performed
according to the criteria specified in this appendix. This appendix
also specifies how and when you must obtain approval of the low-risk
demonstrations for your affected source and how to ensure that your
affected source remains in the low-risk subcategory of PCWP
facilities.
2. Who is eligible to demonstrate that they are part of the low-risk
subcategory of PCWP affected sources?
Each new, reconstructed, or existing affected source at a PCWP
manufacturing facility may demonstrate that they are part of the
low-risk subcategory of PCWP affected sources. Section 63.2232 of 40
CFR part 63, subpart DDDD, defines the affected source and explains
which affected sources are new, existing, or reconstructed.
3. What parts of my affected source have to be included in the low-risk
demonstration?
Every process unit that is part of the PCWP affected source (as
defined in Sec. 63.2292 of 40 CFR part 63, subpart DDDD) and that
emits one or more hazardous air pollutant (HAP) listed in table 1 to
this appendix must be included in the low-risk demonstration. You
are not required to include process units outside of the affected
source in the low-risk demonstration.
4. What are the criteria for determining if my affected source is low
risk?
(a) Determine the individual HAP emission rates from each
process unit emission point within the affected source using the
procedures specified in section 5 of this appendix.
(b) Perform chronic and acute risk assessments using the dose-
response values, as specified in paragraphs (b)(1) through (3) of
this section.
(1) For a look-up table analysis or site-specific chronic
inhalation risk assessment, you should use the cancer and noncancer
dose-response values listed on the Environmental Protection Agency
(EPA) Air Toxics Web site (http://www.epa.gov/ttn/atw/toxsource/summary.html
) to estimate carcinogenic and noncarcinogenic chronic
inhalation risk, respectively.
(2) For site-specific acute inhalation risk assessment, you
should use the acute exposure guidance level (AEGL-1) value for
acrolein and the acute reference exposure level (REL) value for
formaldehyde for estimating acute inhalation risk found at http://www.epa.gov/ttn/atw/toxsource/summary.html
.
(3) You may use dose-response values more health-protective than
those posted on the EPA Air Toxics Web site (http://www.epa.gov/ttn/atw/toxsource/summary.html
) to facilitate ongoing certification (as
required in section 13 of this appendix) that your affected source
remains in the low-risk subcategory.
(c) Demonstrate that your affected source is part of the low-
risk subcategory by estimating the maximum impacts of your affected
source using the methods described in either section 6 of this
appendix (look-up table analysis) or section 7 of this appendix
(site-specific risk assessment) and comparing the results to the
low-risk criteria presented in the applicable section.
5. How do I determine HAP emissions from my affected source?
(a) You must determine HAP emissions for every process unit
emission point within the affected source that emits one or more of
the HAP listed in table 1 to this appendix as specified in table 2A
to this appendix. For each process unit type, table 2A to this
appendix specifies whether emissions testing is required or if
emissions estimation is allowed as an alternative to emissions
testing. If emissions estimation is allowed according to table 2A,
you must develop your emission estimates according to the
requirements in paragraph (k) of this section. You may choose to
perform emissions testing instead of emissions estimation. You must
conduct HAP emissions tests according to the requirements in
paragraphs (b) through (j) of this section and the methods specified
in table 2B to this appendix. If you conduct fuel analyses, you must
follow the requirements of paragraph (m) of this section. For each
of the emission points at your affected source, you must obtain the
emission rates in pounds per hour (lb/hr) for each of the pollutants
listed in table 1 to this appendix.
(b) Periods when emissions tests must be conducted.
(1) You must not conduct emissions tests during periods of
startup, shutdown, or malfunction, as specified in 40 CFR
63.7(e)(1).
(2) You must test under worst-case operating conditions as
defined in this appendix. You must describe your worst-case
operating conditions in your performance test report for the process
and control systems (if applicable) and explain why the conditions
are worst-case.
(c) Number of test runs. You must conduct three separate test
runs for each test required in this section, as specified in 40 CFR
63.7(e)(3). Each test run must last at least 1 hour except for:
testing of a temporary total enclosure (TTE) conducted using Methods
204A through 204F in 40 CFR part 51, appendix M, which require three
separate test runs of at least 3 hours each; and testing of an
enclosure conducted using the alternative tracer gas method in
appendix A to 40 CFR part 63, subpart DDDD, which requires a minimum
of three separate runs of at least 20 minutes each.
(d) Sampling locations. Sampling sites must be located at the
emission point and prior to any releases to the atmosphere. For
example, at the outlet of the control device, including wet control
devices, and prior to any releases to the atmosphere.
(e) Collection of monitoring data for HAP control devices.
During the emissions test, you must collect operating parameter
monitoring system or continuous emissions monitoring system (CEMS)
data at least every 15 minutes during the entire emissions test and
establish the site-specific operating requirements (including the
parameter limits or total hydrocarbon (THC) concentration limit) in
table 2 to 40 CFR part 63, subpart DDDD, using data from the
monitoring system and the procedures specified in paragraphs (k)
through (o) of Sec. 63.2262 of subpart DDDD of 40 CFR part 63.
(f) Nondetect data. You may treat emissions of an individual HAP
as zero if all of the test runs result in a nondetect measurement
and the conditions in paragraphs (1) and (2) of this section are met
for the relevant test method. Otherwise, nondetect data (as defined
in Sec. 63.2292 of 40 CFR part 63, subpart DDDD) for individual HAP
must be treated as one-half of the method detection limit.
(1) The method detection limit is less than or equal to 1 part
per million by volume, dry (ppmvd) for pollutant emissions measured
using Method 320 in appendix A to 40 CFR part 63; or Method 18 in
appendix A to 40 CFR part 60; or the NCASI Method IM/CAN/WP-99.02
(incorporated by reference (IBR), see 40 CFR 63.14(f)); or NCASI
Method ISS/FP-A105.01 (IBR, see 40 CFR 63.14(f); or ASTM D6348-03
(IBR, see 40 CFR 63.14(b)).
(2) For pollutants measured using Method 29 in appendix A to 40
CFR part 60, you analyze samples using atomic absorption
spectroscopy (AAS) or another laboratory method specified in Method
29 in appendix A to 40 CFR part 60 with detection limits lower than
or equal to AAS.
(g) For purposes of your low-risk demonstration, you must assume
that 17
[[Page 8376]]
percent of your total chromium measured using EPA Method 29 in
appendix A to 40 CFR part 60 is chromium VI. You must assume that 65
percent of your total nickel measured using EPA Method 29 in
appendix A to 40 CFR part 60 is nickel subsulfide.
(h) You may use emission rates higher than your measured
emission rates (e.g., emissions rates 10 times your measured
emission rate) to facilitate ongoing certification (as required in
section 13 of this appendix) that your affected source remains in
the low-risk subcategory.
(i) Use of previous emissions tests. You may use the results of
previous emissions tests provided that the following conditions are
met:
(1) The previous emissions tests must have been conducted using
the methods specified in table 2B to this appendix. Previous
emission test results obtained using NCASI Method IM/CAN/WP-99.01
are acceptable.
(2) The previous emissions tests must meet the requirements in
paragraphs (b) through (j) of this section.
(3) The subject process unit(s) must be operated in a manner
(e.g., with raw material type, operating temperature, etc.) that
would be expected to result in the same or lower emissions than
observed during the previous emissions test(s) and the process
unit(s) may not have been modified such that emissions would be
expected to exceed (notwithstanding normal test-to-test variability)
the results from previous emissions test(s).
(4) The previous emissions test(s) must have been conducted in
1997 or later.
(j) Use of test data for similar process units. If you have
multiple similar process units at the same plant site, you may apply
the test results from one of these process units to the other
similar process units for purposes of your low-risk demonstration
provided that the following conditions are met:
(1) You must explain how the process units are similar in terms
of design, function, heating method, raw materials processed,
residence time, change in material moisture content, operating
temperature, resin type processed, age, and any other parameters
that may affect emissions.
(2) If the process units have different throughput rates, then
you must convert the emission test results to terms of pounds of HAP
per unit throughput prior to applying the emissions test data to
other similar process units.
(3) If one of the process units would be expected to exhibit
higher emissions due to minor differences in process parameters,
then you must explain and test the process unit that would be
expected to exhibit greater emissions (for example, the unit with a
slightly higher temperature set point, dryer processing furnish with
slightly higher inlet moisture content, press processing thicker
panels, unit with the greater throughput, considerably older unit,
etc.).
(k) If emissions estimation is allowed, you must follow the
procedures in (1) through (3) of this paragraph.
(1) You must use the emission factors or other emission
estimation techniques specified in table 2A to this appendix when
developing emission estimates.
(2) You must base your emission estimates on the maximum process
unit throughput you will incorporate into your permit according to
section 11(b) of this appendix.
(3) For process units with multiple emission points, you must
apportion the estimate emissions evenly across each emission point.
For example, if you have a process unit with two emission points,
and the process unit is estimated to emit 6 lb/hr, you would assign
3 lb/hr to each emission point.
(l) Testing of multiple stacks. You may test one of multiple
stacks for a process unit provided that the following conditions are
met:
(1) The emissions are produced by the same process unit.
(2) The emissions originate from the same duct.
(3) The emissions are sufficiently mixed so that the gaseous
pollutant concentrations from one stack are not expected to differ
from concentrations from another stack.
(m) Conducting a fuel analysis. For process units that require
testing of metals according to table 2A to this appendix, you may
conduct a fuel analysis in lieu of emissions tests. You must follow
the procedures described in Sec. 63.7521 (a) and (c) through (e) of
subpart DDDDD; Sec. 63.7530(d)(1), (2), and (4) of subpart DDDDD,
and line 2 of table 6 to subpart DDDDD. For purposes of this
appendix, the total selected metals analyzed by fuel analysis are
the metals included in table 1 to this appendix.
6. How do I conduct a look-up table analysis?
Use the look-up tables (tables 3 and 4 to this appendix) to
demonstrate that your affected source is part of the low-risk
subcategory, following the procedures in paragraphs (a) through (d)
of this section.
(a) Using the emission rate of each HAP required to be included
in your low-risk demonstration (determined according to section 5 of
this appendix), calculate your total toxicity-weighted carcinogen
and noncarcinogen emission rates for each of your emission points
using Equations 1 and 2 of this appendix, respectively. Calculate
your carcinogen and non-carcinogen weighted stack height using
Equations 3 and 4 of this appendix, respectively.
[GRAPHIC] [TIFF OMITTED] TR16FE06.000
TWCER = Toxicity-weighted carcinogenic emission rate for each
emission point (lb/hr)/([mu]g/m3)
ERi = Emission rate of pollutant i (lb/hr)
UREi = Unit risk estimate for pollutant i, 1 per
microgram per cubic meter ([mu]g/m3)-1
[GRAPHIC] [TIFF OMITTED] TR16FE06.001
TWNER = Toxicity-weighted noncarcinogenic emission rate for each
emission point (lb/hr)/([mu]g/m3)
ERi = Emission rate of pollutant i (lb/hr)
RfCi = Reference concentration for pollutant i,
micrograms per cubic meter ([mu]g/m3)
[GRAPHIC] [TIFF OMITTED] TR16FE06.002
WHC = Carcinogen weighted stack height for use in the carcinogen
look-up table (table 3 to this appendix)
H = Height of each individual stack or emission point (m)
ep = Individual stacks or emission points
n = Total number of stacks and emission points
[[Page 8377]]
[GRAPHIC] [TIFF OMITTED] TR16FE06.003
WHN = Non-carcinogen weighted stack height for use in the non-
carcinogen look-up table (table 4 to this appendix)
H = Height of each individual stack or emission point (m)
ep = Individual stacks or emission points
n = Total number of stacks and emission points
(b) Cancer risk. Calculate the total toxicity-weighted
carcinogen emission rate for your affected source by summing the
toxicity-weighted carcinogen emission rates for each of your
emission points. Identify the appropriate maximum allowable
toxicity-weighted carcinogen emission rate from table 3 to this
appendix for your affected source using the carcinogen weighted
stack height of your emission points and the minimum distance
between any emission point at the affected source and the property
boundary. If one or both of these values do not match the exact
values in the look-up table, then use the next lowest table value.
(Note: If your weighted stack height is less than 5 meters (m), you
must use the 5 m row.) Your affected source is considered low risk
for carcinogenic effects if your toxicity-weighted carcinogen
emission rate, determined using the methods specified in this
appendix, does not exceed the values specified in table 3 to this
appendix.
(c) Noncancer risk. Calculate the total central nervous system
(CNS) and respiratory target organ specific toxicity-weighted
noncarcinogen emission rate for your affected source by summing the
toxicity-weighted emission rates for each of your emission points.
Identify the appropriate maximum allowable toxicity-weighted
noncarcinogen emission rate from table 4 to this appendix for your
affected source using the non-carcinogen weighted stack height of
your emission points and the minimum distance between any emission
point at the affected source and the property boundary. If one or
both of these values do not match the exact values in the look-up
table, then use the next lowest table value. (Note: If your weighted
stack height is less than 5 m, you must use the 5 m row.) Your
affected source is considered low risk for noncarcinogenic effects
if your toxicity-weighted noncarcinogen emission rate, determined
using the methods specified in this appendix, does not exceed the
values specified in table 4 to this appendix.
(d) Low-risk demonstration. The EPA will approve your affected
source as eligible for membership in the low-risk subcategory of
PCWP affected sources if it determines that: (1) Your affected
source is low risk for both carcinogenic and noncarcinogenic effects
using the look-up table analysis described in this section and (2)
you meet the criteria specified in section 11 of this appendix.
7. How do I conduct a site-specific risk assessment?
(a) Perform a site-specific risk assessment following the
procedures specified in this section. You may use any
scientifically-accepted peer-reviewed assessment methodology for
your site-specific risk assessment. An example of one approach to
performing a site-specific risk assessment for air toxics that may
be appropriate for your affected source can be found in the ``Air
Toxics Risk Assessment Guidance Reference Library, Volume 2, Site-
Specific Risk Assessment Technical Resource Document.'' You may
obtain a copy of the ``Air Toxics Risk Assessment Reference
Library'' through EPA's air toxics Web site at http://www.epa.gov/ttn/fera/risk_atra_main.html
.
(b) At a minimum, your site-specific risk assessment must:
(1) Estimate the long-term inhalation exposures through the
estimation of annual or multi-year average ambient concentrations
for the chronic portion of the assessment.
(2) Estimate the acute exposures for formaldehyde and acrolein
through the estimation of maximum 1-hour average ambient
concentrations for the acute portion of the assessment.
(3) Estimate the inhalation exposure of the individual most
exposed to the affected source's emissions.
(4) Estimate the individual risks over a 70-year lifetime for
the chronic cancer risk assessment.
(5) Use site-specific, quality-assured data wherever possible.
(6) Use health-protective default assumptions wherever site-
specific data are not available.
(7) Contain adequate documentation of the data and methods used
for the assessment so that it is transparent and can be reproduced
by an experienced risk assessor and emission measurement expert.
(c) Your site-specific risk assessment need not:
(1) Assume any attenuation of exposure concentrations due to the
penetration of outdoor pollutants into indoor exposure areas.
(2) Assume any reaction or deposition of the emitted pollutants
during transport from the emission point to the point of exposure.
(d) Your affected source is considered low risk for carcinogenic
chronic inhalation effects if your site-specific risk assessment
demonstrates that maximum off-site individual lifetime cancer risk
at a location where people live or congregate (e.g., school or day
care center) is less than 1 in 1 million.
(e) Your affected source is considered low risk for
noncarcinogenic chronic inhalation effects if your site-specific
risk assessment demonstrates that every maximum off-site target-
organ specific hazard index (TOSHI), or appropriate set of site-
specific hazard indices based on similar or complementary mechanisms
of action that are reasonably likely to be additive at low dose or
dose-response data for mixtures, at a location where people live is
less than or equal to 1.0.
(f) Your affected source is considered low risk for
noncarcinogenic acute inhalation effects if your site-specific risk
assessment demonstrates that the maximum off-site acute hazard
quotients for both acrolein and formaldehyde are less than or equal
to 1.0.
(g) The EPA will approve your affected source as eligible for
membership in the low-risk subcategory of PCWP affected sources if
it determines that: (1) your affected source is low risk for all of
the applicable effects listed in paragraphs (d) through (f) of this
section and (2) you meet the criteria specified in section 11 of
this appendix.
8. What information must I submit for the low-risk demonstration?
(a) Your low-risk demonstration must include at a minimum the
information specified in paragraphs (a)(1) through (5) of this
section and the information specified in either paragraph (b) or (c)
of this section.
(1) Identification of each process unit at the affected source.
(2) Stack parameters for each emission point including, but not
limited to, the parameters listed in paragraphs (a)(2)(i) through
(iv) below:
(i) Emission release type.
(ii) Stack height, stack area, stack gas temperature, and stack
gas exit velocity.
(iii) Plot plan showing all emission points, nearby residences,
and fenceline.
(iv) Identification of any HAP control devices used to reduce
emissions from each process unit.
(3) Emission test reports for each pollutant and process unit
based on the testing requirements and methods specified in tables 2A
and 2B to this appendix, including a description of the process
parameters identified as being worst case. You must submit your
emissions calculations for each pollutant and process unit for which
emissions estimates are developed. You must submit fuel analyses for
each fuel and emission point which has been conducted, including
collection and analytical methods used.
(4) Identification of the dose-response values used in your risk
analysis (look-up table analysis or site-specific risk assessment),
according to section 4(b) of this appendix.
(5) Identification of the controlling process factors
(including, but not limited to, production rate, emission rate, type
of control devices, process parameters documented as worst-case
conditions during the emissions testing used for your low-risk
demonstration) that will become Federally enforceable permit
conditions used to show
[[Page 8378]]
that your affected source remains in the low-risk subcategory.
(b) If you use the look-up table analysis in section 6 of this
appendix to demonstrate that your affected source is low risk, your
low-risk demonstration must contain at a minimum the information in
paragraphs (a) and (b)(1) through (4) of this section.
(1) Identification of the stack heights for each emission point
included in the calculations of weighted stack height.
(2) Identification of the emission point with the minimum
distance to the property boundary.
(3) Calculations used to determine the toxicity-weighted
carcinogen and noncarcinogen emission rates and weighted stack
heights according to section 6(a) of this appendix.
(4) Comparison of the values in the look-up tables (tables 3 and
4 to this appendix) to your toxicity-weighted emission rates for
carcinogenic and noncarcinogenic HAP.
(c) If you use a site-specific risk assessment as described in
section 7 of this appendix to demonstrate that your affected source
is low risk (for carcinogenic and noncarcinogenic chronic inhalation
and acute inhalation risks), your low-risk demonstration must
contain at a minimum the information in paragraphs (a) and (c)(1)
through (8) of this section.
(1) Identification of the risk assessment methodology used.
(2) Documentation of the fate and transport model used.
(3) Documentation of the fate and transport model inputs,
including the information described in paragraphs (a)(1) through (4)
of this section converted to the dimensions required for the model
and all of the following that apply: meteorological data; building,
land use, and terrain data; receptor locations and population data;
and other facility-specific parameters input into the model.
(4) Documentation of the fate and transport model outputs.
(5) Documentation of exposure assessment and risk
characterization calculations.
(6) Comparison of the maximum off-site individual lifetime
cancer risk at a location where people live to 1 in 1 million, as
required in section 7(d) of this appendix for carcinogenic chronic
inhalation risk.
(7) Comparison of the maximum off-site TOSHI for respiratory
effects and CNS effects at a location where people live to the limit
of 1.0, as required in section 7(e) of this appendix for
noncarcinogenic chronic inhalation risk.
(8) Comparison of the maximum off-site acute inhalation hazard
quotient (HQ) for both acrolein and formaldehyde to the limit of
1.0, as required in section 7(f) of this appendix for
noncancinogenic acute inhalation effects.
(d) The EPA may request any additional information it determines
is necessary or appropriate to evaluate an affected source's low-
risk demonstration.
9. Where do I send my low-risk demonstration?
You must submit your low-risk demonstration to the EPA for
review and approval. Send your low-risk demonstration either by e-
mail to REAG@EPA.GOV or by U.S. mail or other mail delivery service
to U.S. EPA, Risk and Exposure Assessment Group, Emission Standards
Division (C404-01), Attn: Group Leader, Research Triangle Park, NC
27711, and send a copy to your permitting authority. Your affected
source is not part of the low-risk subcategory of PCWP facilities
unless and until EPA notifies you that it has determined that you
meet the requirements of section 11 of this appendix.
10. When do I submit my low-risk demonstration?
(a) Existing affected sources. If you have an existing affected
source, you may complete and submit for approval your low-risk
demonstration (including the emission test results, fuel analyses,
and emission estimates required in this appendix) any time. Existing
affected sources that are not approved by EPA as being part of the
low-risk subcategory by October 1, 2008, must comply with the
requirements of 40 CFR part 63, subpart DDDD from October 1, 2008,
unless and until EPA approves them as part of the low-risk
subcategory.
(b) Sources in compliance with 40 CFR part 63, subpart DDDD. If
you operate an affected source that is already in compliance with 40
CFR part 63, subpart DDDD (including, but not limited to, an
existing source, a new or reconstructed affected source starting up
before September 28, 2004, or a new source starting up after
September 28, 2004, but before February 16, 2006) and wish to become
part of the low-risk subcategory, then you may complete and submit
for approval your low-risk demonstration (including the emission
test results, fuel analyses, and emission estimates required in this
appendix) any time. Your affected source will become part of the
low-risk subcategory when EPA determines that the requirements in
section 11 of this appendix are met.
(c) New or reconstructed affected sources wanting to be part of
the low-risk subcategory at startup must comply with the
requirements of paragraphs (c)(1) through (c)(3) of this section.
(1)(i) You must complete and submit for review and approval a
pre-startup low-risk demonstration no later than nine months prior
to initial startup. The pre-startup low-risk demonstration must be
based on the information (e.g., equipment types, estimated emission
rates, etc.) that you will likely use to obtain your title V permit.
You must base your pre-startup low-risk demonstration on the maximum
emissions that will likely be allowed when you obtain your title V
permit.
(ii) You must request that your affected source become part of
the low-risk subcategory based on your pre-startup low-risk
demonstration.
(iii) If EPA approves your pre-startup low-risk demonstration,
then your affected source will be part of the low-risk subcategory
upon approval of the pre-startup low-risk demonstration and you may
start up your affected source without complying with the compliance
options, operating requirements, and work practice requirements in
40 CFR part 63, subpart DDDD, provided that you operate your
affected source consistently with the pre-startup low-risk
demonstration until you meet the criteria in section 11 of this
appendix based on your verification low-risk demonstration developed
according to paragraph (c)(2) of this section. Failure to so operate
will render approval of your pre-startup low-risk demonstration null
and void from the date you startup your affected source.
(2)(i) You must complete and submit your verification low-risk
demonstration, including the results from emission tests (or fuel
analyses) required in this appendix, within 240 days following
initial startup. The verification low-risk demonstration must
demonstrate to EPA's satisfaction that the affected source is low
risk. The verification low-risk demonstration may be used to change
operating parameters ensuring low-risk status.
(ii) If you do not submit the verification low-risk
demonstration as required, or the verification low-risk
demonstration does not verify that the affected source is low risk,
then approval of your pre-startup low-risk demonstration is null and
void from the date you startup your affected source and you must
comply immediately with subpart DDDD of 40 CFR part 63.
(3) To incorporate the low-risk parameters from your
verification low-risk demonstration into your title V permit, you
must submit your application for a significant modification to your
title V permit within 1 year following initial startup, or earlier
if so required under your State's permit program approved under 40
CFR part 70. The parameters that defined your affected source as
part of the low-risk subcategory (including, but not limited to,
production rate, emission rate, type of control devices, process
parameters reflecting the emissions rates used for your low-risk
demonstration, and stack height) must be submitted for incorporation
as federally enforceable terms and conditions into your title V
permit. You must provide written certification to the permitting
authority that your affected source is operating consistently with
its EPA-approved pre-startup low-risk demonstration and verification
low-risk demonstration, as applicable, from startup until your title
V permit revision is issued.
(d) New or reconstructed affected sources that want to operate
consistently with a pre-startup low-risk demonstration at startup
and become part of the low-risk subcategory based on EPA approval of
their verification low-risk demonstration (rather than based on
their pre-startup low-risk demonstration), must comply with the
requirements in paragraphs (d)(1) through (d)(3) of this section.
(1)(i) You must complete and submit for review a pre-startup
low-risk demonstration no later than nine months prior to initial
startup. The pre-startup low-risk demonstration must be based on the
information (e.g., equipment types, estimated emission rates, etc.)
that you will likely use to obtain your title V permit. You must
base your pre-startup low-risk demonstration on the maximum
emissions that will likely be allowed when you obtain your title V
permit.
(ii) If EPA concludes that your pre-startup low-risk
demonstration is complete and
[[Page 8379]]
sufficiently shows that your affected source appears to be eligible
for inclusion in the low-risk subcategory, then you must operate
your affected source consistently with the pre-startup low-risk
demonstration until EPA determines that you meet the criteria in
section 11 of this appendix based on your verification low-risk
demonstration developed according to paragraph (d)(2) of this
section.
(2)(i) You must complete and submit for EPA review and approval
your verification low-risk demonstration, including the results from
emission tests (or fuel analyses) required in this appendix, within
240 days following initial startup. The verification low-risk
demonstration must demonstrate to EPA's satisfaction that the
affected source is low risk.
(ii) You will become part of the low-risk subcategory when EPA
determines that you meet the criteria in section 11 of this appendix
based upon your verification low-risk demonstration. If you do not
submit the verification low-risk demonstration as required, or the
verification low-risk demonstration does not verify that the
affected source is low risk, then EPA will not approve your low-risk
demonstration and you will remain subject to subpart DDDD of 40 CFR
part 63.
(3) To incorporate the low-risk parameters from your
verification low-risk demonstration into your title V permit, you
must submit your application for a significant modification to your
title V permit within 1 year following initial startup, or earlier
if so required by your State's permit program approved by EPA under
40 CFR part 70. The parameters that defined your affected source as
part of the low-risk subcategory (including, but not limited to,
production rate, emission rate, type of control devices, process
parameters reflecting the emissions rates used for your low-risk
demonstration, and stack height) must be submitted for incorporation
as federally enforceable terms and conditions into your title V
permit. You must provide written certification to the permitting
authority that your affected source is operating consistently with
its pre-startup LRD and your verification LRD, as applicable, from
startup until your title V permit revision is issued.
(e) Area sources that become affected sources. If you have an
affected source that is an area source that increases its emissions
or its potential to emit such that it becomes a major source of HAP
before September 28, 2004, then you must complete and submit for
approval your low-risk demonstration as specified in paragraph (a)
of this section. If you have an affected source that is an area
source that increases its emissions or its potential to emit such
that it becomes a major source of HAP after September 28, 2004, then
you must complete and submit for approval your low-risk
demonstration as specified in paragraphs (b), (c) or (d) of this
section, whichever applies.
11. How does my affected source become part of the low-risk subcategory
of PCWP facilities?
For existing sources to be included in the low-risk subcategory,
EPA must find that you meet the criteria in paragraphs (a) and (b)
of this section. For new sources to be included in the low-risk
subcategory, EPA must find that you meet the criteria in paragraph
(a) of this section. Unless and until EPA finds that you meet these
criteria, your affected source is subject to the applicable
compliance options, operating requirements, and work practice
requirements in 40 CFR part 63, subpart DDDD.
(a) Your demonstration of low risk must be approved by EPA.
(b) Following EPA approval, the parameters that defined your
affected source as part of the low-risk subcategory (including, but
not limited to, production rate, emission rate, type of control
devices, process parameters reflecting the emissions rates used for
your low-risk demonstration, and stack height) must be submitted for
incorporation as federally enforceable terms and conditions into
your title V permit. You must submit an application for a
significant permit modification to reopen your title V permit to
incorporate such terms and conditions according to the procedures
and schedules of 40 CFR part 71 or the EPA-approved program in
effect under 40 CFR part 70, as applicable.
12. What must I do to ensure my affected source remains in the low-risk
subcategory of PCWP facilities?
You must meet the requirements in table 2 to 40 CFR part 63,
subpart DDDD, for each HAP control device used at the time when you
completed your low-risk demonstration. You must monitor and collect
data according to Sec. 63.2270 of subpart DDDD to show continuous
compliance with your control device operating requirements. You must
demonstrate continuous compliance with the control device operating
requirements that apply to you by collecting and recording the
monitoring system data listed in table 2 to 40 CFR part 63, subpart
DDDD for the process unit according to Sec. Sec. 63.2269(a), (b),
and (d) of subpart DDDD; and reducing the monitoring system data to
the specified averages in units of the applicable requirement
according to calculations in Sec. 63.2270 of subpart DDDD; and
maintaining the average operating parameter at or above the minimum,
at or below the maximum, or within the range (whichever applies)
established according to section 5(e) of this appendix.
13. What happens if the criteria used in the risk determination change?
(a) You must certify with each annual title V permit compliance
certification that the basis for your affected source's low-risk
determination has not changed. You must submit this certification to
the permitting authority. You must consider the changes in
paragraphs (a)(1) through (5) of this section.
(1) Process changes that increase HAP emissions, including, but
not limited to, a production rate increase, an emission rate
increase, a change in type of control device, changes in process
parameters reflecting emissions rates used for your approved low-
risk demonstration.
(2) Population shifts, such as if people move to a different
location such that their risks from the affected source increase.
(3) Unit risk estimate increases posted on the EPA Web site
(http://www.epa.gov/ttn/atw/toxsource/summary.html) for the
pollutants included in table 1 to this appendix.
(4) Reference concentration changes posted on the EPA Web site
(http://www.epa.gov/ttn/atw/toxsource/summary.html) for the
pollutants included in table 1 to this appendix.
(5) Acute dose-response value for formaldehyde or acrolein
changes.
(b) If your affected source commences operating outside of the
low-risk subcategory, it is no longer part of the low-risk
subcategory. You must be in compliance with 40 CFR part 63, subpart
DDDD as specified in paragraphs (b)(1) through (3) of this section.
Operating outside of the low-risk subcategory means that one of the
changes listed in paragraphs (a)(1) through (5) of this section has
occurred and that the change is inconsistent with your affected
source's title V permit terms and conditions reflecting EPA's
approval of the parameters used in your low-risk demonstration.
(1) You must notify the permitting authority as soon as you
know, or could have reasonably known, that your affected source is
or will be operating outside of the low-risk subcategory.
(2) You must be in compliance with the requirements of 40 CFR
part 63, subpart DDDD as specified in paragraph (b)(2)(i) or (ii) of
this section, whichever applies.
(i) If you are operating outside of the low-risk subcategory due
to a change described in paragraph (a)(1) of this section, then you
must comply with 40 CFR part 63, subpart DDDD beginning on the date
when your affected source commences operating outside the low-risk
subcategory.
(ii) If you are operating outside of the low-risk subcategory
due to a change described in paragraphs (a)(2) through (5) of this
section, then you must comply with 40 CFR part 63, subpart DDDD no
later than 3 years from the date your affected source commences
operating outside the low-risk subcategory.
(3)(i) You must conduct performance tests no later than 180
calendar days after the applicable date specified in paragraph
(b)(2) of this section.
(ii) You must conduct initial compliance demonstrations that do
not require performance tests 30 calendar days after the applicable
date specified in paragraph (b)(2) of this section.
(iii) For the purposes of affected sources affected by this
section, you must refer to the requirements in paragraph (b) of this
section instead of the requirements of Sec. 63.2233 when complying
with 40 CFR part 63, subpart DDDD.
14. What records must I keep?
(a) You must keep records of the information used in developing
the low-risk demonstration for your affected source, including all
of the information specified in section 8 of this appendix.
(b) You must keep records demonstrating continuous compliance
with the operating requirements for control devices.
(c) For each THC CEMS, you must keep the records specified in
Sec. 63.2282(c) of 40 CFR part 63, subpart DDDD.
[[Page 8380]]
15. Definitions
The definitions in Sec. 63.2292 of 40 CFR part 63, subpart
DDDD, apply to this appendix. Additional definitions applicable for
this appendix are as follows:
Agricultural fiber board press means a press used in the
production of an agricultural fiber based composite wood product. An
agricultural fiber board press is a process unit.
Agricultural fiberboard mat dryer means a dryer used to reduce
the moisture of wet-formed agricultural fiber mats by applying heat.
An agricultural fiberboard mat dryer is a process unit.
Ancillary processes mean equipment and process units that are
part of the PCWP affected source that are not defined elsewhere in
this section or in section 63.2292 of subpart DDDD. Ancillary
processes at a specific facility do not include the equipment and
process units identified as insignificant sources of HAP emissions
by that facility, and they do not include equipment and process
units subject to another standard under 40 CFR part 63. Ancillary
processes may be or may not be HAP emissions sources.
Ancillary processes are process units.
Atmospheric refiner means a piece of equipment operated under
atmospheric pressure for refining (rubbing or grinding) the wood
material into fibers or particles. Atmospheric refiners are operated
with continuous infeed and outfeed of wood material and atmospheric
pressures throughout the refining process. An atmospheric refiner is
a process unit.
Blending and forming operations means the process of mixing
adhesive and other additives with the (wood) furnish of the
composite panel and making a mat of resinated fiber, particles, or
strands to be compressed into a reconstituted wood product such as
particleboard, oriented strandboard, or medium density fiberboard.
Blending and forming operations are process units.
Emission point means an individual stack or vent from a process
unit that emits HAP required for inclusion in the low-risk
demonstration specified in this appendix. Process units may have
multiple emission points.
Fiber washer means a unit in which water-soluble components of
wood (hemicellulose and sugars) that have been produced during
digesting and refining are removed from the wood fiber. Typically
wet fiber leaving a refiner is further diluted with water and then
passed over a filter, leaving the cleaned fiber on the surface. A
fiber washer is a process unit.
Finishing sander means a piece of equipment that uses an
abrasive drum, belt, or pad to impart smoothness to the surface of a
plywood or composite wood product panel and to reduce the panel to
the prescribed thickness. A finishing sander is a process unit.
Finishing saw means a piece of equipment used to trim or cut
finished plywood and composite wood products panels to a certain
size. A finishing saw is a process unit.
Hardwood plywood press means a hot press which, through heat and
pressure, bonds assembled hardwood veneers (including multiple plies
of veneer and/or a substrate) and resin into a hardwood plywood
panel. A hardwood plywood press is a process unit.
Hardwood veneer kiln means an enclosed dryer operated in batch
cycles by applying heat to reduce the moisture content from stacked
hardwood veneer. A hardwood veneer kiln is a process unit.
Hazard Index (HI) means the sum of more than one hazard quotient
for multiple substances and/or multiple exposure pathways.
Hazard Quotient (HQ) means the ratio of the predicted media
concentration of a pollutant to the media concentration at which no
adverse effects are expected. For inhalation exposures, the HQ is
calculated as the air concentration divided by the reference
concentration (RfC).
Humidifier means a process unit used to increase the moisture
content of hardboard following pressing or after post-baking.
Typically, water vapor saturated air is blown over the hardboard
surfaces in a closed cabinet. A humidifier is a process unit.
I-joist curing chamber means an oven or a room surrounded by a
solid wall or heavy plastic flaps that uses heat, infrared, or
radio-frequency techniques to cure the adhesive. An I-joist curing
chamber is a process unit.
Log chipping means the production of wood chips from logs.
Log vat means a process unit that raises the temperature of the
logs inside by applying a heated substance, usually hot water and
steam, to the outside of the logs by spraying or soaking. A log vat
is a process unit.
Look-up table analysis means a risk screening analysis based on
comparing the toxicity-weighted HAP emission rate from the affected
source to the maximum allowable toxicity-weighted HAP emission rates
specified in tables 3 and 4 to this appendix.
LSL press means a composite wood product press that presses a
loose mat of resinated strands into a billet by simultaneous
application of heat and pressure. The billet is cut into laminated
strand lumber after exiting the press. An LSL press is a process
unit.
LVL or PSL press means a composite wood product press that
presses resinated stacks of veneers into a solid billet by
application of heat and/or pressure. The billet is cut into
laminated veneer lumber or parallel strand lumber after exiting the
press. An LVL or PSL press is a process unit.
Natural gas means a naturally occurring mixture of hydrocarbon
and non-hydrocarbon gases found in geologic formations beneath the
earth's surface. The principal hydrocarbon constituent is methane.
Paddle-type particleboard dryer means a dryer to which heat is
applied to remove moisture from particles and paddles to advance
materials through the dryer. This type of dryer removes moisture
absorbed by particles due to high ambient temperature. A paddle-type
particleboard dryer is a process unit.
Panel-trim chipper means a piece of equipment that accepts the
discarded pieces of veneer or pressed plywood and composite wood
products panels that are removed by finishing saws and reduces these
pieces to small elements. A panel-trim chipper is a process unit.
Particleboard extruder means a heated die oriented either
horizontally or vertically through which resinated particles are
continuously forced to form extruded particleboard products. A
particleboard extruder is a process unit.
Particleboard press mold means a press that consists of molds
that apply heat and pressure to form molded or shaped particleboard
products. A particleboard press mold is a process unit.
Propane means a colorless gas derived from petroleum and natural
gas, with the molecular structure C3H8.
Radio-frequency veneer redryer means a dryer heated by radio-
frequency waves that is used to redry veneer that has been
previously dried. A radio-frequency veneer redryer is a process
unit.
Reference Concentration (RfC) means an estimate (with
uncertainty spanning perhaps an order of magnitude) of a continuous
inhalation exposure to the human population (including sensitive
subgroups) that is likely to be without an appreciable risk of
deleterious effects during a lifetime. It can be derived from
various types of human or animal data, with uncertainty factors
generally applied to reflect limitations of the data used.
Resin storage tank means any storage tank, container, or vessel
connected to plywood and composite wood product production that
holds resin additives (in liquid form) containing any of the HAP
listed in table 2A to this appendix. A resin storage tank is a
process unit.
Rotary agricultural fiber dryer means a rotary dryer operated by
applying heat to reduce the moisture of agricultural fiber. A rotary
agricultural fiber dryer is a process unit.
Softwood plywood press means a hot press which, through heat and
pressure, bonds assembled softwood veneer plies and resin into a
softwood plywood panel. A softwood plywood press is a process unit.
Softwood veneer kiln means an enclosed dryer operated in batch
cycles by applying heat to reduce the moisture content from stacked
softwood veneer. A softwood veneer kiln is a process unit.
Stand-alone digester means a pressure vessel used to heat and
soften wood chips (usually by steaming) before the chips are sent to
a separate process unit for refining into fiber. A stand-alone
digester is a process unit.
Target organ specific hazard index (TOSHI) means the sum of
hazard quotients for individual chemicals that affect the same organ
or organ system (e.g., respiratory system, central nervous system).
Unit Risk Estimate (URE) means the upper-bound excess lifetime
cancer risk estimated to result from continuous exposure to an agent
at a concentration of 1 microgram per cubic meter ([mu]g/
m3) in air.
Wastewater/process water operation means equipment that
processes water in plywood or composite wood product facilities for
[[Page 8381]]
reuse or disposal. Wastewater/process water operations includes but
is not limited to pumps, holding ponds and tanks, cooling and
heating operations, settling systems, filtration systems, aeration
systems, clarifiers, pH adjustment systems, log storage ponds,
pollution control device water (including wash water), vacuum
distillation systems, sludge drying and disposal systems, spray
irrigation fields, and connections to POTW facilities. Wastewater/
process water operations are process units.
Worst-case operating conditions means operation of a process
unit during emissions testing under the conditions that result in
the highest HAP emissions or that result in the emissions stream
composition (including HAP and non-HAP) that is most challenging for
the control device if a control device is used. For example, worst
case conditions could include operation of the process unit at
maximum throughput, at its highest temperature, with the wood
species mix likely to produce the most HAP, and/or with the resin
formulation containing the greatest HAP.
Table 1 to Appendix B to Subpart DDDD of 40 CFR Part 63.--HAP That Must
Be Included in the Demonstration of Eligibility for the Low-risk PCWP
Subcategory
------------------------------------------------------------------------
For your analysis of the following You must include the following
effects . . . HAP . . .
------------------------------------------------------------------------
(1) Chronic inhalation carcinogenic acetaldehyde, benzene, arsenic,
effects. beryllium, cadmium, chromium,
lead, nickel, and
formaldehyde.
(2) Chronic inhalation noncarcinogenic acetaldehyde, acrolein,
respiratory effects. cadmium, formaldehyde, and
methylene diphenyl
diisocyanate (MDI).
(3) Chronic inhalation noncarcinogenic manganese, lead, and phenol.
CNS effects.
(4) Acute inhalation................... acrolein and formaldehyde.
------------------------------------------------------------------------
Table 2A to Appendix B to Subpart DDDD of 40 CFR Part 63.--Testing and Emissions Estimation Specifications for Process Units
------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------
HAP metals from
Process unit type Acetaldehyde Acrolein Formaldehyde Phenol Benzene MDI direct-fired process
units \a\
------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------
Agricultural fiberboard mat Test................. Test................. Test................. Test................. Test................. NA.................. Test or fuel
dryers, Dry rotary dryers, analysis.
Fiberboard mat dryer (heated
zones), Green rotary dryers,
Hardboard ovens, Hardwood veneer
dryers (heated zones), Paddle-
type particleboard dryers, Press
predryers, Rotary agricultural
fiber dryers, Rotary strand
dryers, Softwood veneer dryers
(heated zones), Veneer redryers
(heated by conventional means).
Atmospheric refiners, Conveyor Test................. Test................. Test................. Test................. Test................. NA.................. NA.
strand dryers, Pressurized
refiners.
Primary tube dryers, Secondary Test................. Test................. Test................. Test................. Test................. Test if processing Test or fuel
tube dryers. furnish with MDI analysis.
resin added prior
to drying.
Agricultural fiber board presses, Test................. Test................. Test................. Test................. Test................. Test if board NA
Reconstituted wood products contains MDI resin.
presses, Reconstituted wood
product board coolers.
Blending and forming operations-- NA................... NA................... 0.060 lb/ODT\b\...... NA................... NA................... Engineering estimate NA.
particleboard and MDF. if MDI resin used.
Blending and forming operations-- NA................... NA................... 0.0036 lb/MSF \3/8\'' Engineering estimate. NA................... Engineering estimate NA.
OSB. press throughput. if MDI resin used.
Dry forming--hardboard........... Engineering estimate. NA................... Engineering estimate. Engineering estimate. NA................... NA.................. NA.
Fiber washers.................... 0.015 lb/ODT......... NA................... 0.0026 lb/ODT........ NA................... NA................... NA.................. NA.
Fiberboard mat dryer (fugitive 0.0055 lb/MSF \1/2\'' NA................... 0.031 lb/MSF \1/2\''. NA................... NA................... NA.................. NA.
emissions).
[[Page 8382]]
Finishing sanders................ 0.0031 lb/MSF........ NA................... 0.0042 lb/MSF........ 0.015 lb/MSF......... NA................... Engineering estimate NA.
if MDI resin used.
Finishing saws................... 0.00092 lb/MSF \3/ NA................... 0.00034 lb/MSF \3/ 0.0057 lb/MSF........ NA................... Engineering estimate NA.
8\''. 8\''. if MDI resin used.
Hardwood plywood presses......... NA................... NA................... 0.0088 lb/MSF \3/8\'' 0.016 lb/MSF \3/8\''. NA................... NA.................. NA.
Hardwood veneer dryer (cooling 0.058 lb/MSF \3/8\''. NA................... 0.013 lb/MSF \3/8\''. NA................... NA................... NA.................. NA.
zones).
Hardwood veneer kilns............ 0.067 lb/MSF \3/8\''. NA................... 0.016 lb/MSF \3/8\''. 0.0053 lb/MSF \3/ NA................... NA.................. NA.
8\'',.
Humidifiers...................... 0.0018 lb/MSF \1/8\'' 0.0087 lb/MSF \1/8\'' 0.0010 lb/MSF \1/8\'' 0.00057 lb/MSF \1/ 0.0000062 lb/MSF \1/ NA.................. NA.
8\''. 8\''.
I-joist curing chambers.......... NA................... NA................... 0.00018 lb/MLF....... NA................... NA................... Engineering estimate NA.
if MDI resin used.
Log vats......................... 0.0047 lb/MSF \3/8\'' NA................... NA................... NA................... NA................... NA.................. NA.
removed from vat per
hour.
LSL presses...................... Engineering estimate. NA................... 0.029 lb/1000 ft\3\.. Engineering estimate. NA................... 0.18 lb/1000 ft\3\.. NA.
LVL presses...................... 0.29 lb/1000 ft\3\... NA................... 0.79 lb/1000 ft\3\... NA................... NA................... NA.................. NA.
Lumber kilns..................... 0.065 lb/MBF or 0.009 lb/MBF or 0.034 lb/MBF or 0.010 lb/MBF or NA................... NA.................. Engineering
conduct small-scale conduct small-scale conduct small-scale conduct small-scale estimate.
kiln testing kiln testing kiln testing kiln testing
according to according to according to according to
appendix C to appendix C to appendix C to appendix C to
subpart DDDD. subpart DDDD. subpart DDDD. subpart DDDD.
Panel-trim chippers.............. 0.00081 lb/MSF \3/ NA................... 0.00034 lb/MSF \3/ 0.0019 lb/MSF \3/8\'' NA................... NA.................. NA.
8\'' finished board 8\'' finished board finished board
production. production. production.
Particleboard press molds, 0.034 lb/MSF \3/4\''. 0.0087 lb/MSF \3/4\'' 0.64 lb/MSF \3/4\''.. 0.024 lb/MSF \3/4\''. 0.0073 lb/MSF \3/4\'' NA.................. NA.
Particleboard extruders.
Radio-frequency veneer redryers.. 0.0029 lb/MSF \3/8\'' NA................... 0.00065 lb/MSF \3/ NA................... NA................... NA.................. NA.
8\''.
Resin storage tanks--closed roof. NA................... NA................... For tanks with resin For tanks with resin NA................... For tanks with MDI NA.
containing containing phenol, resin, 0.0013 lb/hr
formaldehyde, 0.001 0.0002 lb/hr per per tank OR model
lb/hr per tank OR tank OR model using using TANKS
model using TANKS TANKS software\c\. software\c\.
software\c\.
Resin storage tanks--open roof... NA................... NA................... Engineering estimate Engineering estimate NA................... Engineering estimate NA.
if resin contains if resin contains if resin contains
formaldehyde. phenol. MDI.
Softwood plywood presses......... 0.012 lb/MSF \3/8\''. NA................... 0.0054 lb/MSF \3/8\'' 0.0022 lb/MSF \3/8\'' NA................... NA.................. NA.
Softwood veneer dryers (cooling 0.012 lb/MSF \3/8\''. NA................... 0.0028 lb/MSF \3/8\'' 0.011 lb/MSF \3/8\''. NA................... NA.................. NA.
zones).
Softwood veneer kilns............ 0.097 lb/MSF \3/8\''. 0.012 lb/MSF \3/8\''. 0.10 lb/MSF \3/8\''.. 0.020 lb/MSF \3/8\''. 0.0078 lb/MSF \3/8\'' NA.................. NA.
[[Page 8383]]
Stand-alone digesters............ 0.030 lb/ODT......... 0.0024 lb/ODT........ 0.0045 lb/ODT........ 0.0012 lb/ODT........ NA................... NA.................. NA.
Wastewater/process water Engineering estimate Engineering estimate Engineering estimate Engineering estimate Engineering estimate NA.................. NA.
operations. (such as WATER9\c\ (such as WATER9\c\ (such as WATER9\c\ (such as WATER9\c\ (such as WATER9\c\
or other method). or other method). or other method). or other method). or other method).
Wet forming--fiberboard and 0.0075 lb/MSF \1/2\'' NA................... 0.0036 lb/MSF \1/2\'' NA................... NA................... NA.................. NA.
hardboard (without PF resin).
Wet forming--hardboard (PF resin) 0.0067 lb/ODT........ NA................... 0.00039 lb/ODT....... 0.00075 lb/ODT....... NA................... NA.................. NA.
Miscellaneous coating operations, NA................... NA................... NA................... NA................... NA................... NA.................. NA.
Log chipping, Softwood veneer
dryer fugitive emissions.
Other ancillary processes (not Engineering estimate. Engineering estimate. Engineering estimate. Engineering estimate. Engineering estimate. Engineering estimate Engineering
listed elsewhere in this table) estimate.
that may emit HAP listed in this
table.
------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------
Test: Emissions testing must be conducted for the process unit and pollutant according to the test methods specified in table 2B to appendix B to subpart DDDD.
NA: Not applicable. No emission estimates or emissions tests are required for purposes of the low-risk demonstration.
lb/MSF: Pounds of HAP per thousand square feet of board of the inches thickness specified (e.g., lb/MSF \3/4\ = pounds of HAP per thousand square feet of \3/4\-inch board). See equation in
Sec. 63.2262(j) of subpart DDDD to convert from one thickness basis to another.
lb/ODT: Pounds of HAP per oven dried ton of wood material.
lb/MBF: Pounds of HAP per thousand board feet.
lb/MLF: Pounds of HAP per thousand linear feet
\a\ Direct-fired process units firing natural gas or propane are NA; thus, no emissions estimates, emissions tests, or fuel analyses are required for the purposes of the low-risk
demonstration.
\b\ Estimation of formaldehyde emissions is only necessary for facilities that use resin containing formaldehyde.
\c\ TANKS and WATER9 software is available at http://www.epa.gov/ttn/chief/software/index.html.
Table 2B to Appendix B to Subpart DDDD of 40 CFR part 63.--Emission Test
Methods
------------------------------------------------------------------------
For . . . You must . . . Using . . .
------------------------------------------------------------------------
(1) each process unit select sampling Method 1 or 1A of 40
required to be tested ports' location and CFR part 60,
according to table 2A to the number of appendix A (as
this appendix. traverse points. appropriate).
(2) each process unit determine velocity Method 2 in addition
required to be tested and volumetric flow to Method 2A, 2C,
according to table 2A to rate;. 2D, 2F, or 2G in
this appendix. appendix A to 40
CFR part 60 (as
appropriate).
(3) each process unit conduct gas Method 3, 3A, or 3B
required to be tested molecular weight in appendix A to 40
according to table 2A to analysis. CFR part 60 (as
this appendix. appropriate).
(4) each process unit measure moisture Method 4 in appendix
required to be tested content of the A to 40 CFR part
according to table 2A to stack gas. 60.
this appendix.
(5) each process unit measure emissions of NCASI Method IM/CAN/
required to be tested acetaldehyde. WP-99.02 (IBR, see
according to table 2A to 40 CFR 63.14(f));
this appendix. OR Method 320 in
appendix A to 40
CFR part 63; OR the
NCASI Method ISS/FP-
A105.01 (IBR, see
Sec. 63.14(f));
OR Method 0011 in
``Test Methods for
Evaluating Solid
Waste, Physical/
Chemical Methods''
(EPA Publication
No. SW-846); OR
ASTM D6348-03\b\
(IBR, see 40 CFR
63.14(b)).
(6) each process unit measure emissions of NCASI Method IM/CAN/
required to be tested acrolein. WP-99.02 (IBR, see
according to table 2A to 40 CFR 63.14(f));
this appendix. OR Method 320 in
appendix A to 40
CFR part 63; OR the
NCASI Method ISS/FP-
A105.01 (IBR, see
Sec. 63.14(f));
OR ASTM D6348-03 b
(IBR, see 40 CFR
63.14(b)).
[[Page 8384]]
(7) each process unit measure emissions of NCASI Method IM/CAN/
required to be tested formaldehyde. WP-99.02 (IBR, see
according to table 2A to 40 CFR 63.14(f));
this appendix. OR Method 320 in
appendix A to 40
CFR part 63; OR the
NCASI Method ISS/FP-
A105.01 (IBR, see
Sec. 63.14(f));
OR the NCASI Method
CI/WP-98.01; OR
Method 316 in
appendix A to 40
CFR part 63; OR
Method 0011 in
``Test Methods for
Evaluating Solid
Waste, Physical/
Chemical Methods''
(EPA Publication
No. SW-846); OR
ASTM D6348-03 b
(IBR, see 40 CFR
63.14(b)).
(8) each process unit measure emissions of NCASI Method IM/CAN/
required to be tested phenol. WP-99.02 (IBR, see
according to table 2A to 40 CFR 63.14(f));
this appendix. OR Method 320 in
appendix A to 40
CFR part 63; OR the
NCASI Method ISS/FP-
A105.01 (IBR, see
Sec. 63.14(f));
OR the NCASI Method
CI/WP-98.01; OR
ASTM D6348-03 b
(IBR, see 40 CFR
63.14(b)).
(9) each process unit measure emissions of Method 18 in
required to be tested benzene. appendix A to 40
according to table 2A to CFR part 60; OR
this appendix. NCASI Method IM/CAN/
WP-99.02 (IBR, see
40 CFR 63.14(f));
OR Method 320 in
appendix A to 40
CFR part 63; OR
ASTM D6348-03 b
(IBR, see 40 CFR
63.14(b)).
(10) each process unit that measure emissions of Method 320 in
processes material MDI. appendix A to 40
containing MDI resin CFR part 63; OR
required to be tested Method 207 in
according to table 2A to appendix M to 40
this appendix. CFR part 51; OR
Conditional Test
Method (CTM) 031
which is posted on
http://www.epa.gov/
ttn/emc/ctm.html
(11) each direct-fired measure emissions of Method 29 in
process unit a required to the following HAP appendix A to 40
be tested according to metals: Arsenic, CFR part 60 OR fuel
table 2A to this appendix. beryllium, cadmium, analysis (see
chromium, lead, section 5(m) of
manganese, and this appendix).
nickel..
(12) each reconstituted wood meet the design Methods 204 and 204A
product press or specifications through 204F of 40
reconstituted wood product included in the CFR part 51,
board cooler with a HAP definition of wood appendix M to
control device. products enclosure determine capture
in Sec. 63.2292 efficiency (except
of subpart DDDD of for wood products
40 CFR part 63; or enclosures as
determine the defined in Sec.
percent capture 63.2292).
efficiency of the Enclosures that
enclosure directing meet the definition
emissions to an add- of wood products
on control device. enclosure or that
meet Method 204
requirements for a
PTE are assumed to
have a capture
efficiency of 100
percent. Enclosures
that do not meet
either the PTE
requirements or
design criteria for
a wood products
enclosure must
determine the
capture efficiency
by constructing a
TTE according to
the requirements of
Method 204 and
applying Methods
204A through 204F
(as appropriate).
As an alternative to
Methods 204 and
204A through 204F,
you may use the
tracer gas method
contained in
appendix A to
subpart DDDD.
(13) each reconstituted wood determine the a TTE and Methods
product press or percent capture 204 and 204A
reconstituted wood product efficiency. through 204F (as
board cooler required to be appropriate) of 40
tested according to table CFR part 51,
2A to this appendix. appendix M. As an
alternative to
installing a TTE
and using Methods
204 and 204A
through 204F, you
may use the tracer
gas method
contained in
appendix A to
subpart DDDD.
Enclosures that
meet the design
criteria (1)
through (4) in the
definition of wood
products enclosure,
or that meet Method
204 requirements
for a PTE (except
for the criteria
specified in
section 6.2 of
Method 204) are
assumed to have a
capture efficiency
of 100 percent.
Measured emissions
divided by the
capture efficiency
provides the
emission rate.
Fugitive emissions
are equal to the
difference in the
emission rate and
measured emissions.
[[Page 8385]]
(14) each process unit with establish the site- data from the
a HAP control device specific operating parameter
required to be tested requirements monitoring system
according to table 2A to (including the or THC CEMS and the
this appendix. parameter limits or applicable
THC concentration performance test
limits) in table 2 method(s).
to subpart DDDD.
------------------------------------------------------------------------
a Excludes direct-fired process units fired with only natural gas or
propane.
b Provided that percent R as determined in Annex A5 of ASTM D6348-03 is
equal or greater than 70 percent and less than or equal to 130
percent.
[[Page 8386]]
Table 3 to Appendix B to Subpart DDDD of 40 CFR Part 63.--Maximum Allowable Toxicity-Weighted Carcinogen Emission Rate
[(lb/hr)/([mu]g/m3)]
------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------
Distance to property boundary (m)
Stack height (m) -----------------------------------------------------------------------------------------------------------------------------------------------------------
0 50 100 150 200 250 500 1000 1500 2000 3000 5000
------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------
5................................... 8.72E-07 8.72E-07 8.72E-07 9.63E-07 1.25E-06 1.51E-06 2.66E-06 4.25E-06 4.39E-06 4.39E-06 4.39E-06 5.00E-06
10.................................. 2.47E-06 2.47E-06 2.47E-06 2.47E-06 2.47E-06 2.61E-06 3.58E-06 5.03E-06 5.89E-06 5.89E-06 5.89E-06 6.16E-06
20.................................. 5.81E-06 5.81E-06 5.81E-06 5.81E-06 5.81E-06 5.81E-06 5.90E-06 7.39E-06 8.90E-06 9.97E-06 9.97E-06 1.12E-05
30.................................. 7.74E-06 7.74E-06 7.74E-06 7.74E-06 7.74E-06 7.74E-06 8.28E-06 9.49E-06 1.17E-05 1.35E-05 1.55E-05 1.61E-05
40.................................. 9.20E-06 9.20E-06 9.20E-06 9.20E-06 9.20E-06 9.20E-06 9.24E-06 1.17E-05 1.34E-05 1.51E-05 1.98E-05 2.22E-05
50.................................. 1.02E-05 1.02E-05 1.02E-05 1.02E-05 1.02E-05 1.02E-05 1.02E-05 1.36E-05 1.53E-05 1.66E-05 2.37E-05 2.95E-05
60.................................. 1.13E-05 1.13E-05 1.13E-05 1.13E-05 1.13E-05 1.13E-05 1.13E-05 1.53E-05 1.76E-05 1.85E-05 2.51E-05 3.45E-05
70.................................. 1.23E-05 1.23E-05 1.23E-05 1.23E-05 1.23E-05 1.23E-05 1.23E-05 1.72E-05 2.04E-05 2.06E-05 2.66E-05 4.07E-05
80.................................. 1.34E-05 1.34E-05 1.34E-05 1.34E-05 1.34E-05 1.34E-05 1.34E-05 1.92E-05 2.15E-05 2.31E-05 2.82E-05 4.34E-05
100................................. 1.52E-05 1.52E-05 1.52E-05 1.52E-05 1.52E-05 1.52E-05 1.52E-05 1.97E-05 2.40E-05 2.79E-05 3.17E-05 4.49E-05
200................................. 1.76E-05 1.76E-05 1.76E-05 1.76E-05 1.76E-05 1.76E-05 1.76E-05 2.06E-05 2.94E-05 3.24E-05 4.03E-05 5.04E-05
------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------
MIR=1E-06.
Table 4 to Appendix B to Subpart DDDD of 40 CFR Part 63.--Maximum Allowable Toxicity-Weighted Noncarcinogen Emission Rate
[(lb/hr)/([mu]g/m3)]
------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------
Distance to property boundary (m)
Stack height (m) -----------------------------------------------------------------------------------------------------------------------------------------------------------
0 50 100 150 200 250 500 1000 1500 2000 3000 5000
------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------
5................................... 2.51E-01 2.51E-01 3.16E-01 3.16E-01 3.16E-01 3.16E-01 3.16E-01 3.46E-01 4.66E-01 6.21E-01 9.82E-01 1.80E+00
10.................................. 5.62E-01 5.62E-01 5.62E-01 5.62E-01 5.62E-01 5.62E-01 5.62E-01 5.70E-01 6.33E-01 7.71E-01 1.13E+00 1.97E+00
20.................................. 1.43E+00 1.43E+00 1.43E+00 1.43E+00 1.43E+00 1.43E+00 1.43E+00 1.43E+00 1.68E+00 1.83E+00 2.26E+00 3.51E+00
30.................................. 2.36E+00 2.36E+00 2.36E+00 2.36E+00 2.36E+00 2.36E+00 2.53E+00 3.04E+00 3.04E+00 3.33E+00 4.45E+00 5.81E+00
40.................................. 3.11E+00 3.11E+00 3.11E+00 3.11E+00 3.11E+00 3.11E+00 3.42E+00 4.04E+00 5.07E+00 5.51E+00 6.39E+00 9.63E+00
50.................................. 3.93E+00 3.93E+00 3.93E+00 3.93E+00 3.93E+00 3.93E+00 4.49E+00 4.92E+00 6.95E+00 7.35E+00 8.99E+00 1.25E+01
60.................................. 4.83E+00 4.83E+00 4.83E+00 4.83E+00 4.83E+00 4.83E+00 5.56E+00 6.13E+00 7.80E+00 1.01E+01 1.10E+01 1.63E+01
70.................................. 5.77E+00 5.77E+00 5.77E+00 5.77E+00 5.77E+00 5.77E+00 6.45E+00 7.71E+00 8.83E+00 1.18E+01 1.36E+01 1.86E+01
80.................................. 6.74E+00 6.74E+00 6.74E+00 6.74E+00 6.74E+00 6.74E+00 7.12E+00 9.50E+00 1.01E+01 1.29E+01 1.72E+01 2.13E+01
100................................. 8.87E+00 8.87E+00 8.87E+00 8.87E+00 8.87E+00 8.87E+00 8.88E+00 1.19E+01 1.37E+01 1.55E+01 2.38E+01 2.89E+01
200................................. 1.70E+01 1.70E+01 1.70E+01 1.70E+01 1.70E+01 1.70E+01 1.70E+01 2.05E+01 2.93E+01 3.06E+01 4.02E+01 4.93E+01
------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------
HI=1.
[[Page 8387]]
0
13. Add appendix C to subpart DDDD to read as follows:
Appendix C to Subpart DDDD of Part 63--Considerations for a Small-Scale
Kiln Emission Testing Program
1.0 Purpose
Emissions test data from small-scale lumber kilns can be used to
reasonably approximate emissions from full-scale lumber kilns if
representative lumber samples are dried and the venting
characteristics of the small-scale kiln mimic those of the full-
scale kiln. This appendix provides a list of considerations that
must be taken into account by facilities conducting small-scale
lumber kiln emissions testing to approximate emissions from their
full-scale lumber kilns for purposes of the low-risk demonstration
described under appendix B to subpart DDDD of part 63.
The considerations described in this appendix apply only for
small-scale lumber kiln emissions testing conducted to provide data
for the low-risk demonstration described under appendix B to subpart
DDDD of part 63. Permitting authorities may require different
procedures for testing or estimating lumber kiln emissions for
purposes other than the low-risk demonstration described under
appendix B to subpart DDDD of part 63.
2.0 Considerations for Lumber Samples
2.1 A written plan must be developed for obtaining
representative lumber samples to use as charges at the small-scale
kilns. The plan must discuss how the samples are selected and
handled and the basis upon which they are considered to be
representative. If possible, information on the harvest site, date
harvested, segregation from other lumber (if segregated), and
processing at the sawmill must be included. If this information is
unavailable, a general description of the sawmill's wood procurement
and processing practices must be provided. The affected source and
testing laboratory must approve the written test plan before
beginning the small-scale kiln testing.
2.2 Samples must not be subject to significant air drying during
processing, shipping, or storage prior to charging into the small-
scale kiln.
2.3 Enough lumber must be collected to provide for extra lumber
charges in case of testing failures.
2.4 Information on the lumber used for each small-scale kiln
charge must be reported including the items in paragraphs 2.4.1
though 2.4.4 of this section:
2.4.1 Total kiln charge, board feet,
2.4.2 Nominal dimensions of lumber dried (for example, 2x4s),
2.4.3 Moisture content (dry basis) of the green lumber, and
2.4.4 Moisture content (dry basis) of the kiln dried lumber.
3.0 Considerations for Kiln Operating Parameters
The small-scale kiln must operate in a similar manner to the
full-scale kilns for items 3.1 through 3.3 of this section. The
small-scale kiln must operate in a reasonably consistent manner from
charge-to-charge for all items (3.1 through 3.5) listed in this
section.
3.1 Air velocity through the kiln charge.
3.2 Temperature profiles or kiln schedules (wet-bulb/dry-bulb
temperatures throughout the kiln cycle).
3.3 Ending moisture content (dry basis) of the lumber (may need
to be mathematically adjusted for small-scale kilns).
3.4 Kiln venting profile (trend) for the sample event/kiln cycle
(normalized to a board foot or thousand board feet).
3.5 Mass emission rate profile (trend) for the sample event/kiln
cycle.
4.0 Considerations for Emission Sampling
4.1 Sample equipment must be able to sample gases with high
moisture content.
4.2 You must accurately measure/calculate total kiln exhaust and
exhaust moisture content. If direct measurements are impractical
other methods used must be explicitly discussed in the report.
4.3 You must accurately measure the concentration of the
compounds of concern either in the kiln exhaust or at a proper
location within the kiln.
5.0 Considerations for Sample Intervals and Sampling Runs
5.1 A minimum of two full kiln cycles or batches must be tested
to determine the emissions for a particular wood species or for a
facility utilizing only one wood species.
5.2 You may use a single kiln cycle for emission values for wood
species that require more than 3 days to dry.
5.3 Since kiln drying cycles typically exceed 20 hours, it is
suggested that sampling be conducted in intervals throughout the
drying cycle. Three hours provide a reasonable sample interval
(sample run), but sampling equipment or manpower may dictate other
schedules. Sampling equipment ``turnaround'' will result in gaps in
the kiln emission data. The gaps must not exceed 45% of the kiln
cycle. Data for the gaps occurring at certain periods of time in the
drying cycle can be calculated by linear interpolation from the
sampling values on either side of the gap. Other techniques may be
required if the data gap occurs when the measured data exhibit high
levels of variability. As a minimum, sampling intervals must include
initial hours of the kiln operating cycle once the kiln has warmed
to target wet bulb and/or dry bulb temperatures and begins venting,
hours of kiln operation during the middle of the kiln drying cycle,
and hours of kiln operation towards the end of the kiln drying
cycle.
5.4 The final production-based mass emission rate for the small-
scale kiln sample event is determined by integrating the area under
the mass emission rate profile curve.
6.0 Considerations for Reporting
The emissions report must contain the information in paragraphs
6.1 through 6.9 of this section.
6.1 Graphical, charge-by-charge results for items 3.2, 3.4, and
3.5 above and numerical data for items 3.1 and 3.3. Describe how the
full-scale kiln operates in comparison to the small-scale kiln in
order to show that the full-scale kiln drying cycle was reasonably
reproduced in the small-scale kiln.
6.2 A moisture balance by comparing the water loss (from the
green versus dry lumber charge weight difference) to the water
exhausted from the kiln (using the exhaust flow rate and moisture
content of the exhaust).
6.3 A description of the sampling system and sampling
methodology.
6.4 A summary and background data for all quality assurance
measures required by the sampling methods.
6.5 Discussion of method detection limits and treatment of
values below the detection limit.
6.6 An example of emission rate calculations.
6.7 Explanation or reference to the methodology used to
calculate emissions to the target or desired ending lumber moisture
content.
6.8 Information outlined in section 2.0 of this appendix,
including a discussion of collection and handling of lumber samples.
6.9 Data and show calculations for developed emission factors.
7.0 Guidance
7.1 NCASI Technical Bulletin 845 provides a large amount of
detail that can be of assistance in many phases of a small-scale
kiln testing program. This report should be viewed as ``one way,''
not ``the only way'' to conduct testing.
7.2 Oregon State University, Mississippi State University, the
University of Idaho, and others have published information regarding
operation and testing of small-scale kilns. These publications are a
very good source of information on small-scale kilns.
[FR Doc. 06-1071 Filed 2-15-06; 8:45 am]
BILLING CODE 6560-50-P