[Federal Register Volume 69, Number 146 (Friday, July 30, 2004)]
[Rules and Regulations]
[Pages 45944-46045]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 04-6298]



[[Page 45943]]

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Part IV





Environmental Protection Agency





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40 CFR Parts 63 and 429



National Emission Standards for Hazardous Air Pollutants: Plywood and 
Composite Wood Products; Effluent Limitations Guidelines and Standards 
for the Timber Products Point Source Category; List of Hazardous Air 
Pollutants, Lesser Quantity Designations, Source Category List; Final 
Rule

  Federal Register / Vol. 69, No. 146 / Friday, July 30, 2004 / Rules 
and Regulations  

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ENVIRONMENTAL PROTECTION AGENCY

40 CFR Parts 63 and 429

[OAR-2003-0048, FRL-7634-1]
RIN 2060-AG52


National Emission Standards for Hazardous Air Pollutants: Plywood 
and Composite Wood Products; Effluent Limitations Guidelines and 
Standards for the Timber Products Point Source Category; List of 
Hazardous Air Pollutants, Lesser Quantity Designations, Source Category 
List

AGENCY: Environmental Protection Agency (EPA).

ACTION: Final rule.

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SUMMARY: This action promulgates national emission standards for 
hazardous air pollutants (NESHAP) for the plywood and composite wood 
products (PCWP) source category under the Clean Air Act (CAA) and 
revisions to the effluent limitations, guidelines and standards for the 
timber products processing source category under the Clean Water Act 
(CWA).
    The EPA has determined that the PCWP source category contains major 
sources of hazardous air pollutants (HAP), including, but not limited 
to, acetaldehyde, acrolein, formaldehyde, methanol, phenol, and 
propionaldehyde. These HAP are associated with a variety of adverse 
health effects. These adverse health effects include chronic health 
disorders (e.g., damage to nasal membranes, gastrointestinal 
irritation) and acute health disorders (e.g., irritation of eyes, 
throat, and mucous membranes, dizziness, headache, and nausea). Three 
of the six primary HAP emitted have been classified as probable or 
possible human carcinogens. This action will implement section 112(d) 
of the CAA by requiring all major sources subject to the final rule to 
meet HAP emission standards reflecting the application of the maximum 
achievable control technology (MACT). The final rule will reduce HAP 
emissions from the PCWP source category by approximately 5,900 to 9,900 
megagrams per year (Mg/yr) (6,600 to 11,000 tons per year (tons/yr)). 
In addition, the final rule will reduce emissions of volatile organic 
compounds (VOC) by 13,000 to 25,000 Mg/yr (14,000 to 27,000 tons/yr).
    The EPA is also amending the effluent limitations, guidelines and 
standards for the timber products processing point source category 
(veneer, plywood, dry process hardboard, particleboard manufacturing 
subcategories). The amendments adjust the definition of process 
wastewater to exclude certain sources of wastewater generated by air 
pollution control devices expected to be installed to comply with the 
final PCWP NESHAP.
    The EPA is also amending the list of categories that was developed 
pursuant to section 112(c)(1) of the CAA. The EPA is delisting a low-
risk subcategory of the PCWP source category. This action is being 
taken in part to respond to comments submitted by the American Forest & 
Paper Association (AF&PA) and in part upon the Administrator's own 
motion, pursuant to section 112(c)(9) of the CAA. This action is based 
on EPA's evaluation of the available information concerning the 
potential hazards from exposure to HAP emitted by PCWP affected 
sources, and includes a detailed rationale for removing low-risk PCWP 
affected sources from the source category list.

DATES: The final NESHAP and the amendments to the effluent guidelines 
are effective September 28, 2004. The incorporation by reference of 
certain publications listed in the final NESHAP is approved by the 
director of the Office of the Federal Register as of September 28, 
2004.

ADDRESSES: Docket numbers OAR-2003-0048 and A-98-44, containing 
supporting documentation used in development of this action, are 
available for public viewing at the EPA Docket Center (Air Docket), EPA 
West, Room B-108, 1301 Constitution Avenue, NW., Washington, DC 20460. 
These dockets also contain documentation supporting the amendments to 
40 CFR part 429.

FOR FURTHER INFORMATION CONTACT: For further information concerning 
applicability and rule determinations, contact the appropriate State or 
local agency representative. If no State or local representative is 
available, contact the EPA Regional Office staff listed in 40 CFR 
63.13. For information concerning the analyses performed in developing 
the final rule, contact Ms. Mary Tom Kissell, Waste and Chemical 
Processes Group, Emission Standards Division (C439-03), U.S. EPA, 
Research Triangle Park, North Carolina 27711, telephone number (919) 
541-4516, electronic mail (e-mail) address [email protected]. For 
information concerning test methods, sampling, and monitoring 
information, contact Mr. Gary McAlister, Source Measurement Analysis 
Group, Emission Monitoring and Analysis Division (D243-02), U.S. EPA, 
Research Triangle Park, North Carolina 27711, telephone number (919) 
541-1062, e-mail address [email protected]. For information 
concerning the economic impacts and benefit analysis, contact Mr. Larry 
Sorrels, Innovative Strategies and Economics Group, Air Quality 
Strategies and Standards Division (C339-01), U.S. EPA, Research 
Triangle Park, North Carolina 27711, telephone number (919) 541-5041, 
e-mail address [email protected]. For information concerning the 
effluent guidelines, contact Mr. Donald Anderson, Engineering and 
Analysis Division (4303T), U.S. EPA, 1200 Pennsylvania Avenue, NW., 
Washington, DC 20460, telephone number (202) 566-1021, 
[email protected].

SUPPLEMENTARY INFORMATION: Regulated Entities. Categories and entities 
potentially regulated by this action include:

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                                                                SIC code    NAICS       Examples of regulated
               Category                          Rule               a      code b             entities
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Industry.............................  NESHAP.................      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
                                                                                     (particleboard, medium
                                                                                     density fiberboard,
                                                                                     hardboard, fiberboard, and
                                                                                     oriented strandboard
                                                                                     plants).
                                                                    2439    321213  Structural Wood Members, Not
                                                                                     Elsewhere Classified
                                                                                     (engineered wood products
                                                                                     plants).
Effluent Guidelines..................  .......................      2436    321212  Softwood plywood and veneer
                                                                                     plants.
                                                                    2493    321219  Reconstituted wood products
                                                                                     (particleboard, medium
                                                                                     density fiberboard,
                                                                                     hardboard, fiberboard, and
                                                                                     oriented strandboard
                                                                                     plants).
----------------------------------------------------------------------------------------------------------------
\a\ Standard Industrial Classification.
\b\ North American Industrial Classification System.


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    This table is not intended to be exhaustive, but rather provides a 
guide for readers regarding entities likely to be regulated by this 
action. To determine whether your facility is regulated by this action, 
you should examine the applicability criteria in Sec.  63.2231 of the 
final rule. If you have any questions regarding the applicability of 
this action to a particular entity, consult the person listed in the 
preceding FOR FURTHER INFORMATION CONTACT section.
    Docket. The EPA has established an official public docket for this 
action including both Docket ID No. OAR-2003-0048 and Docket ID No. A-
98-44. The official public docket consists of the documents 
specifically referenced in this action, any public comments received, 
and other information related to this action. All items may not be 
listed under both docket numbers, so interested parties should inspect 
both docket numbers to ensure that they have received all materials 
relevant to this rule. Although a part of the official docket, the 
public docket does not include Confidential Business Information or 
other information whose disclosure is restricted by statute. The 
official public docket is available for public viewing at the EPA 
Docket Center (Air Docket), EPA West, Room B-102, 1301 Constitution 
Avenue, NW., Washington, DC. The EPA Docket Center 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 Docket is (202) 
566-1742.
    Electronic Access. You may access this Federal Register document 
electronically through the EPA Internet under the Federal Register 
listings at http://www.epa.gov/fedrgstr/. You may also access a copy of 
this document through the Technology Transfer Network (TTN) at http://www.epa.gov/ttn/atw/plypart/plywoodpg.html. An electronic version of 
the public docket is available through EPA's electronic public docket 
and comment system, EPA Dockets. You may use EPA Dockets at http://www.epa.gov/edocket/ to view public comments, access the index listing 
of the contents of the official public docket, and access those 
documents in the public docket that are available electronically. 
Although not all docket materials may be available electronically, you 
may still access any of the publicly available docket materials through 
the docket facility identified above. Once in the system, select 
``search,'' then key in the appropriate docket identification number.
    Judicial Review. Under section 307(b)(1) of the CAA, judicial 
review of the standards and limitations of the final rule is available 
only by filing a petition for review in the U.S. Court of Appeals for 
the District of Columbia Circuit by September 28, 2004. Under section 
307(d)(7)(B) of the CAA, only an objection to the final rule that was 
raised with reasonable specificity during the period for public comment 
can be raised during judicial review. Under section 509(b)(1) of the 
CWA, judicial review of today's effluent limitations guidelines and 
standards is available in the United States Court of Appeals by filing 
a petition for review within 120 days from the date of promulgation of 
those guidelines and standards. In accordance with 40 CFR 23.2, the 
water portion of today's final rule shall be considered promulgated for 
the purposes of judicial review at 1 p.m. Eastern time on August 13, 
2004. Moreover, under section 307(b)(2) of the CAA and section 
509(b)(2) of the CWA, the requirements established by the final rule 
may not be challenged separately in any civil or criminal proceedings 
brought by EPA to enforce the requirements.
    Outline. The information presented in this preamble is organized as 
follows:

I. Introduction
    A. What Is the Source of Authority for Development of Today's 
Regulations?
    B. What Criteria Are Used in the Development of NESHAP?
    C. How Was the Final Rule Developed?
    D. What Are the Health Effects of the Pollutants Emitted From 
the PCWP Industry?
    E. Incorporation by Reference of NCASI Test Methods
    F. Incorporation by Reference of ASTM Test Method

II. Summary of the Final Rule

    A. What Process Units Are Subject to the Final Rule?
    B. What Pollutants Are Regulated by the Final Rule?
    C. What Are the Compliance Options?
    D. What Operating Requirements Are in the Final Rule?
    E. What Are the Work Practice Requirements?
    F. When Must I Comply With the Final Rule?
    G. How Do I Demonstrate Initial Compliance With the Final Rule?
    H. How do I Demonstrate Continuous Compliance With the Final 
Rule?
    I. How Do I Demonstrate That My Affected Source Is Part of the 
Low-risk Subcategory?

III. Summary of Environmental, Energy, and Economic Impacts

    A. How Many Facilities Are Impacted by the Final Rule?
    B. What Are the Air Quality Impacts?
    C. What Are the Water Quality Impacts?
    D. What Are the Solid Waste Impacts?
    E. What Are the Energy Impacts?
    F. What Are the Cost Impacts?
    G. What Are the Economic Impacts?
    H. What Are the Social Costs and Benefits?

IV. Summary of Responses to Major Comments and Changes to the 
Plywood and Composite Wood Products NESHAP

    A. Applicability
    B. Overlap With Other Rules
    C. Amendments to the Effluent Guidelines for Timber Products 
Processing
    D. Existing Source MACT
    E. New Source MACT
    F. Definition of Control Device
    G. Compliance Options
    H. Testing and Monitoring Requirements
    I. Routine Control Device Maintenance Exemption (RCDME)
    J. Startup, Shutdown, and Malfunction (SSM)
    K. Risk-Based Approaches

V. Statutory and Executive Order Reviews

    A. Executive Order 12866: Regulatory Planning and Review
    B. Paperwork Reduction Act
    C. Regulatory Flexibility Analysis
    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 & 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. Introduction

A. What Is the Source of Authority for Development of Today's 
Regulations?

    Section 112(c) of the CAA requires us to list categories and 
subcategories of major sources and area sources of HAP and to establish 
NESHAP for the listed source categories and subcategories. The PCWP 
source category was originally listed as the plywood and particleboard 
source category on July 16, 1992 (57 FR 31576). The name of the source 
category was changed to plywood and composite wood products on November 
18, 1999 (64 FR 63025), to more accurately reflect the types of 
manufacturing facilities covered by the source category. In addition, 
when we proposed the PCWP rule on January 9, 2003 (68 FR 1276), we 
broadened the scope of the source category to include lumber kilns 
located at stand-alone kiln-dried lumber manufacturing facilities or at 
any other type of facility. Major sources of HAP are those that have 
the potential to emit 9.1 Mg/yr (10 tons/yr) or more of any one HAP or 
22.3 Mg/yr (25 tons/yr) or more of any combination of HAP.
    Section 112(d) of the CAA directs us to adopt emission standards 
for

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categories and subcategories of HAP sources. In cases where emission 
standards are not feasible, section 112(h) of the CAA allows us to 
develop design, equipment, work practice, and/or operational standards. 
The collection of compliance options, operating requirements, and work 
practice requirements in today's final rule make up the emission 
standards and work practice standards for the PCWP NESHAP.
    We are promulgating the amendments to 40 CFR part 429 under the 
authority of sections 301, 304, 306, 307, 308, 402, and 501 of the CWA.
    Section 112(c)(9) of the CAA allows us to delete categories and 
subcategories from the list of HAP sources to be subject to MACT 
standards under section 112(d) of the CAA, if certain substantive 
criteria are met. (The EPA construes this authority to apply to listed 
subcategories because doing so is logical in the context of the general 
regulatory scheme established by the statute, and is reasonable since 
section 112(c)(9)(B)(ii) expressly refers to subcategories.) To delete 
a category or subcategory the Administrator must make an initial 
demonstration that no source in the category or subcategory: (1) Emits 
carcinogens in amounts that may result in a lifetime cancer risk 
exceeding one in a million to the individual most exposed; (2) emits 
noncarcinogens in amounts that exceed a level which is adequate to 
provide an ample margin of safety to protect public health; and (3) 
emits any HAP or combination of HAP in amounts that will result in an 
adverse environmental effect, as defined by section 112(a)(7) of the 
CAA.

B. What Criteria Are Used in the Development of NESHAP?

    Section 112(d)(1) of the CAA requires that we establish NESHAP for 
the control of HAP from both new and existing major sources. Section 
112(d)(2) of the CAA requires the NESHAP to reflect the maximum degree 
of reduction in emissions of HAP that is achievable. This level of 
control is commonly referred to as the MACT.
    The MACT floor is the minimum control level allowed for NESHAP and 
is defined under section 112(d)(3) of the CAA. In essence, the MACT 
floor ensures that the standard is set at a level that ensures that all 
major sources achieve a level of control at least as stringent as that 
already achieved by the better-controlled and lower-emitting sources in 
each source category or subcategory. For new sources, the MACT floor 
cannot be less stringent than the emission control that is achieved in 
practice by the best-controlled similar source. The MACT standards for 
existing sources can be less stringent than standards for new sources, 
but they cannot be less stringent than the average emission limitation 
achieved by the best-performing 12 percent of existing sources in the 
category or subcategory (or the best-performing 5 sources for 
categories or subcategories with fewer than 30 sources).
    In developing MACT under section 112(d)(2) of the CAA, we must also 
consider any control options that are more stringent than the floor. We 
may establish standards more stringent than the floor based on the 
consideration of cost of achieving the emissions reductions, any non-
air quality health and environmental impacts, and energy requirements.

C. How Was the Final Rule Developed?

    We proposed standards for PCWP on January 9, 2003 (68 FR 1276). The 
preamble for the proposed standards described the rationale for the 
proposed standards. Public comments were solicited at the time of 
proposal. The public comment period lasted from January 9, 2003, to 
March 10, 2003. Industry representatives, regulatory agencies, 
environmental groups, and the general public were given the opportunity 
to comment on the proposed rule and to provide additional information 
during the public comment period. We also offered at proposal the 
opportunity for a public hearing concerning the proposed rule, but no 
hearing was requested. We met with stakeholders on several occasions.
    We received a total of 57 public comment letters on the proposed 
rule during the comment period. Comments were submitted by industry 
trade associations, PCWP companies, State regulatory agencies, local 
government agencies, and environmental groups. Today's final rule 
reflects our consideration of all of the comments received during the 
comment period. Major public comments on the proposed rule, along with 
our responses to those comments, are summarized in this preamble.

D. What Are the Health Effects of the Pollutants Emitted From the PCWP 
Industry?

    The final rule protects air quality and promotes the public health 
by reducing emissions of some of the HAP listed in section 112(b)(1) of 
the CAA. The organic HAP from PCWP process units that have been 
detected in one or more emission tests include acetaldehyde, 
acetophenone, acrolein, benzene, biphenyl, bromomethane, carbon 
disulfide, carbon tetrachloride, chloroform, chloroethane, 
chloromethane, cresols, cumene, ethyl benzene, formaldehyde, 
hydroquinone methanol, methylene chloride, methylene diphenyl 
diisocyanate (MDI), methyl ethyl ketone (MEK), methyl isobutyl ketone 
(MIBK), n-hexane, phenol, propionaldehyde, styrene, toluene, xylenes, 
1,1,1-trichloroethane, bis-(2-ethylhexyl phthalate), 4-methyl-2-
pentanone, and di-n-butyl phthalate. Many of these HAP are rarely 
detected and occur infrequently. The predominant organic HAP emitted 
(i.e., those most likely to be emitted in detectable quantities and 
with high mass relative to other HAP) by PCWP facilities include 
acetaldehyde, acrolein, formaldehyde, methanol, phenol, and 
propionaldehyde. Exposure to these compounds has been demonstrated to 
cause adverse health effects when present in concentrations higher than 
those typically found in ambient air. This section discusses the health 
effects associated with the predominant HAP emitted by the PCWP 
industry, as well as the health effects of the HAP contributing the 
most to cancer and noncancer risks associated with these PCWP 
facilities (organic HAP and some metal HAP) that must be included in 
any demonstration of eligibility for the low-risk subcategory of PCWP 
sources.
    We do not have the necessary data on each PCWP facility and the 
people living around each facility to determine the actual population 
exposures to the HAP emitted from these facilities and the potential 
health effects. Our screening assessment, conducted using health-
protective assumptions, indicates that potential noncancer health 
impacts were negligible to target organ systems other than the central 
nervous and respiratory systems. Furthermore, only acrolein and 
formaldehyde showed the potential for acute exposures of any concern. 
Therefore, noncancer effects other than those effecting the central 
nervous or respiratory systems are not expected to occur prior to or 
after regulation, and are provided below only to illustrate the nature 
of the contaminant's effects at high dose. However, to the extent the 
adverse effects do occur, today's final rule would reduce emissions by 
sources subject to the standards and subsequent exposures to such 
emissions.
1. Acetaldehyde
    Acetaldehyde is ubiquitous in the environment and may be formed in 
the body from the breakdown of ethanol (ethyl alcohol). In humans, 
symptoms of chronic (long-term) exposure to

[[Page 45947]]

acetaldehyde resemble those of alcoholism. Long-term inhalation 
exposure studies in animals reported effects on the nasal epithelium 
and mucous membranes, growth retardation, and increased kidney weight. 
We have classified acetaldehyde as a probable human carcinogen (Group 
B2) based on animal studies that have shown nasal tumors in rats and 
laryngeal tumors in hamsters.
2. Acrolein
    Acute (short-term) inhalation exposure to acrolein may result in 
upper respiratory tract irritation and congestion. The major effects 
from chronic (long-term) inhalation exposure to acrolein in humans 
consist of general respiratory congestion and eye, nose, and throat 
irritation. Acrolein is a strong dermal irritant in humans. We consider 
acrolein to be a possible human carcinogen (Group C) based on limited 
animal cancer data suggesting an increased incidence of tumors in rats 
exposed to acrolein in the drinking water.
3. Formaldehyde
    Both acute (short-term) and chronic (long-term) exposure to 
formaldehyde irritates the eyes, nose, and throat. Limited human 
studies have reported an association between formaldehyde exposure and 
lung and nasopharyngeal cancer. Animal inhalation studies have reported 
an increased incidence of nasal squamous cell cancer. We consider 
formaldehyde a probable human carcinogen (Group B2).
4. Methanol
    Chronic (long-term) exposure of humans to methanol by inhalation or 
ingestion may result in blurred vision, headache, dizziness, and 
nausea. No information is available on the reproductive, developmental, 
or carcinogenic effects of methanol in humans. Birth defects have been 
observed in the offspring of rats and mice exposed to high 
concentrations of methanol by inhalation. A methanol inhalation study 
using rhesus monkeys reported a decrease in the length of pregnancy and 
limited evidence of impaired learning ability in offspring. We have not 
classified methanol with respect to carcinogenicity.
5. Phenol
    Oral exposure to small amounts of phenol may cause irregular 
breathing and muscular weakness. Anorexia, progressive weight loss, 
diarrhea, vertigo, salivation, and a dark coloration of the urine have 
been reported in chronically (long-term) exposed humans. 
Gastrointestinal irritation and blood and liver effects have also been 
reported. No studies of developmental or reproductive effects of phenol 
in humans are available, but animal studies have reported reduced fetal 
body weights, growth retardation, and abnormal development in the 
offspring of animals exposed to relatively high doses of phenol by the 
oral route. We have classified phenol in Group D, not classifiable as 
to human carcinogenicity.
6. Propionaldehyde
    Animal studies have reported that inhalation exposure to high 
levels of propionaldehyde results in anesthesia and liver damage. No 
information is available on the chronic (long-term), reproductive, 
developmental, or carcinogenic effects of propionaldehyde in animals or 
humans. We have not classified propionaldehyde for carcinogenicity.
7. Arsenic
    Chronic (long-term) inhalation exposure to inorganic arsenic in 
humans is associated with irritation of the skin and mucous membranes. 
Human data suggest a relationship between inhalation exposure of women 
working at or living near metal smelters and an increased risk of 
reproductive effects. Inorganic arsenic exposure in humans by the 
inhalation route has been shown to be strongly associated with lung 
cancer. We have classified inorganic arsenic as a Group A, human 
carcinogen.
8. Beryllium
    Chronic (long-term) inhalation exposure of humans to beryllium has 
been reported to cause chronic beryllium disease (berylliosis), in 
which granulomatous (noncancerous) lesions develop in the lung. 
Inhalation exposure to beryllium has been demonstrated to cause lung 
cancer in rats and monkeys. Human studies are limited, but suggest a 
causal relationship between beryllium exposure and an increased risk of 
lung cancer. We have classified beryllium as a Group B1, probable human 
carcinogen, when inhaled; data are inadequate to determine whether 
beryllium is carcinogenic when ingested.
9. Cadmium
    Chronic (long-term) inhalation or oral exposure to cadmium leads to 
a build-up of cadmium in the kidneys that can cause kidney disease. 
Cadmium has been shown to be a developmental toxicant at high doses in 
animals, resulting in fetal malformations and other effects, but no 
conclusive evidence exists in humans. Animal studies have demonstrated 
an increase in lung cancer from long-term inhalation exposure to 
cadmium. We have classified cadmium as a Group B1, probable human 
carcinogen when inhaled; data are inadequate to determine whether 
cadmium is carcinogenic when ingested.
10. Chromium
    Chromium may be emitted from PCWP facilities in two forms, 
trivalent chromium (chromium III) or hexavalent chromium (chromium VI). 
The respiratory tract is the major target organ for chromium VI 
toxicity. Bronchitis, decreased pulmonary function, pneumonia, and 
other respiratory effects have been noted from chronic high 
concentration exposure. Limited human studies suggest that chromium VI 
inhalation exposure may be associated with complications during 
pregnancy and childbirth, while animal studies have not reported 
reproductive effects from inhalation exposure to chromium VI. Human and 
animal studies have clearly established that inhaled chromium VI is a 
carcinogen, resulting in an increased risk of lung cancer. We have 
classified chromium VI as a Group A, human carcinogen by the inhalation 
exposure route.
    Chromium III is much less toxic than chromium VI. The respiratory 
tract is also the major target organ for chromium III toxicity, similar 
to chromium VI. Chromium III is an essential element in humans, with a 
daily oral intake of 50 to 200 micrograms per day ([mu]g/d) recommended 
for an adult. Data on adverse effects of high oral exposures of 
chromium III are not available for humans, but a study with mice 
suggests possible damage to the male reproductive tract. We have not 
classified chromium III for carcinogenicity.
11. Manganese
    Health effects in humans have been associated with both 
deficiencies and excess intakes of manganese. Chronic (long-term) 
exposure to low levels of manganese in the diet is considered to be 
nutritionally essential in humans, with a recommended daily allowance 
of 2 to 5 milligrams per day (mg/d). Chronic inhalation exposure to 
high levels of manganese by inhalation in humans results primarily in 
central nervous system (CNS) effects. Visual reaction time, hand 
steadiness, and eye-hand coordination were affected in chronically-
exposed workers. Impotence and loss of libido have been noted in male 
workers afflicted with manganism

[[Page 45948]]

attributed to high-dose inhalation exposures. We have classified 
manganese as Group D, not classifiable as to human carcinogenicity.
12. Nickel
    Nickel is an essential element in some animal species, and it has 
been suggested it may be essential for human nutrition. Nickel 
dermatitis, consisting of itching of the fingers, hands, and forearms, 
is the most common effect in humans from chronic (long-term) skin 
contact with nickel. Respiratory effects have also been reported in 
humans from inhalation exposure to nickel. No information is available 
regarding the reproductive or developmental effects of nickel in 
humans, but animal studies have reported such effects, although a 
consistent dose-response relationship has not been seen. The forms of 
nickel which might be emitted from PCWP facilities include soluble 
nickel, nickel subsulfide, and nickel carbonyl. We have classified 
nickel refinery dust and nickel subsulfide as Group A, human 
carcinogens, and nickel carbonyl as a Group B2, probable human 
carcinogen, by inhalation exposure. Human and animal studies have 
reported an increased risk of lung and nasal cancers from exposure to 
nickel refinery dusts and nickel subsulfide. Animal inhalation studies 
of soluble nickel compounds (i.e., nickel carbonyl) have reported lung 
tumors.
13. Lead
    Elemental lead may cause a variety of effects at low oral or 
inhaled dose levels. Chronic (long-term) exposure to high levels of 
lead in humans results in effects on the blood, CNS, blood pressure, 
and kidneys. Children are particularly sensitive to the chronic effects 
of lead, with slowed cognitive development, reduced growth, and other 
effects reported. Reproductive effects, such as decreased sperm count 
in men and spontaneous abortions in women, have been associated with 
lead exposure. The developing fetus is at particular risk from maternal 
lead exposure, with low birth weight and slowed postnatal 
neurobehavioral development noted. Human studies are inconclusive 
regarding lead exposure and cancer, while animal studies have reported 
an increase in kidney cancer from lead exposure by the oral route. We 
have classified lead as a Group B2, probable human carcinogen.
14. MDI
    The MDI has been observed to irritate the skin and eyes of rabbits. 
Chronic (long-term) inhalation exposure to MDI may cause asthma, 
dyspnea, and other respiratory impairments in workers. We have 
classified MDI within Group D, not classifiable as to human 
carcinogenicity.
15. Benzene
    Chronic (long-term) inhalation exposure has caused various 
disorders in the blood, including reduced numbers of red blood cells. 
Increased incidence of leukemia (cancer of the tissues that form white 
blood cells) has been observed in humans occupationally exposed to 
benzene. We have classified benzene as a Group A, known human 
carcinogen.

E. Incorporation by Reference of NCASI Test Methods

    Today's final rule amends 40 CFR 63.14 by revising paragraph (f) to 
incorporate by reference two test methods developed by the National 
Council of the Paper Industry for Air and Stream Improvement (NCASI): 
(1) Method CI/WP-98.01, ``Chilled Impinger Method for Use at Wood 
Products Mills to Measure Formaldehyde, Methanol, and Phenol'; and (2) 
NCASI Method IM/CAN/WP-99.02, ``Impinger/Canister Source Sampling 
Method for Selected HAPs and Other Compounds at Wood Products 
Facilities.'' These methods are available from NCASI, Methods Manual, 
P.O. Box 133318, Research Triangle Park, NC 27709-3318 or at http://www.ncasi.org. They are also available from the docket for the final 
rule (Docket Number OAR-2003-0048 and Docket Number A-98-44). These 
documents were 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.

F. Incorporation by Reference of ASTM Test Method

    Today's final rule amends 40 CFR 63.14 by adding paragraph (b)(54) 
to incorporate by reference a test method developed by the American 
Society for Testing and Materials (ASTM), ASTM D6348-03, ``Standard 
Test Method for Determination of Gaseous Compounds by Extractive Direct 
Interface Fourier Transform Infrared (FTIR) Spectroscopy.'' This test 
method is available from ASTM, 100 Barr Harbor Drive, Post Office Box 
C700, West Conshohocken, PA 19428-2959; or ProQuest, 300 North Zeeb 
Road, Ann Arbor, MI 48106. This document has been approved for 
incorporation by reference by the Director of the Federal Register in 
accordance with 5 U.S.C. 552(a) and 1 CFR 51.

II. Summary of the Final Rule

A. What Process Units Are Subject to the Final Rule?

    The final rule regulates HAP emissions from PCWP facilities that 
are major sources. Plywood and composite wood products are manufactured 
by bonding wood material (fibers, particles, strands, etc.) or 
agricultural fiber, generally with resin under heat and pressure, to 
form a structural panel or engineered wood product. 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, oriented strandboard, 
hardboard, fiberboard, medium density fiberboard, laminated strand 
lumber, laminated veneer lumber, wood I-joists, kiln-dried lumber, and 
glue-laminated beams. Table 1 of this preamble lists the process units 
at PCWP facilities and indicates which process units are subject to the 
control requirements in today's final rule. ``Process unit'' means 
equipment classified according to its function such as a blender, 
dryer, press, former, or board cooler.
    The affected source for the final rule is the combination of all 
PCWP manufacturing operations, including PCWP process units, onsite 
storage of raw materials, onsite wastewater treatment operations 
associated with PCWP manufacturing, and miscellaneous coating 
operations located at a major source facility. One of the implications 
of this definition of affected source is that the control requirements, 
or ``floor,'' as defined in section 112(d)(3), are determined for the 
entire PCWP facility. Therefore, except for lumber kilns not otherwise 
located at PCWP facilities, the final rule contains the control 
requirements that represent the MACT level of control for the entire 
facility. For lumber kilns not otherwise located at PCWP facilities, 
the final rule contains the control requirements that represent the 
MACT level of control only for lumber kilns.

[[Page 45949]]



      Table 1.--Process Units That Are Subject to the Final Control
                              Requirements
------------------------------------------------------------------------
                                      Does today's final rule include
                                      control requirements for . . .
 For the following process units ---------------------------------------
              . . .                Existing affected     New affected
                                       sources?            sources?
------------------------------------------------------------------------
Softwood veneer dryers a;         Yes.                Yes.
 primary tube dryers; secondary
 tube dryers; rotary strand
 dryers; conveyor strand dryers;
 green rotary dryers; hardboard
 ovens; reconstituted wood
 product presses; and
 pressurized refiners.
Press predryers; fiberboard mat   No.                 Yes.
 dryers; and board coolers.
Dry rotary dryers a; veneer       No.                 No.
 redryers a; softwood plywood
 presses; hardwood plywood
 presses; engineered wood
 products presses; hardwood
 veneer dryers a; humidifiers;
 atmospheric refiners; formers;
 blenders; rotary agricultural
 fiber dryers; agricultural
 fiber board presses; sanders;
 saws; fiber washers; chippers;
 log vats; lumber kilns; storage
 tanks; wastewater operations;
 miscellaneous coating
 operations (including group 1
 miscellaneous coating
 operations a); and stand-alone
 digesters.
------------------------------------------------------------------------
a These process units have work practice requirements in today's final
  rule in addition to or instead of control requirements. Group 1
  miscellaneous coating operations include application of edge seals,
  nail lines, logo (or other information) paint, shelving edge fillers,
  trademark/grade-stamp inks, and wood putty patches to PCWP (except
  kiln-dried lumber) on the same site where the PCWP are manufactured.
  Group 1 miscellaneous coating operations also include application of
  synthetic patches to plywood at new affected sources.

B. What Pollutants Are Regulated by the Final Rule?

    The final rule regulates HAP emissions from PCWP facilities. For 
the purpose of compliance with 40 CFR part 63, subpart DDDD, we defined 
``total HAP'' to be the sum of the emissions of six primary HAP emitted 
from PCWP manufacturing. The six HAP that define total HAP make up 96 
percent of the nationwide HAP emissions from PCWP facilities and are 
acetaldehyde, acrolein, formaldehyde, methanol, phenol, and 
propionaldehyde. Other HAP are sometimes emitted and controlled along 
with these six HAP, but in lower quantities. Depending upon which of 
the compliance alternatives you choose, you could be required to 
measure emissions of total HAP, total hydrocarbon (THC), methanol, or 
formaldehyde as surrogates for measuring all HAP. For the purpose of 
determining whether your facility is a major source, you would have to 
include all HAP as prescribed by rules and guidance pertaining to 
determination of major source.

C. What Are the Compliance Options?

    Today's final rule includes a range of compliance options, which 
are summarized in the following subsections. You must use one of the 
compliance options to show compliance with the final rule. In most 
cases, the compliance options are the same for new and existing 
sources. Dilution to achieve compliance is prohibited, as specified in 
40 CFR 63.4.
1. Production-Based Compliance Options
    Today's final rule includes production-based compliance options 
(PBCO), which are based on total HAP and vary according to type of 
process unit. Total HAP emissions are defined in today's final rule as 
the total mass emissions of the following six HAP: acetaldehyde, 
acrolein, formaldehyde, methanol, phenol, and propionaldehyde. The PBCO 
are in units of mass of pollutant per unit of production. Add-on 
control systems may not be used to meet the production-based compliance 
options. For pressurized refiners and most dryers, the PBCO are 
expressed as pounds per oven-dried-ton of wood (lb/ODT). For presses, 
hardboard ovens, and some dryers, the PBCO are expressed as pounds per 
thousand square feet of board (lb/MSF), with a reference board 
thickness. There is no PBCO for conveyor strand dryers.
2. Add-On Control System Compliance Options
    If you operate a process unit equipped with an add-on control 
system, you may use any one of the following six compliance options. 
``Add-on control system'' or ``control system'' means the combination 
of capture and control devices used to reduce HAP emissions to the 
atmosphere.
    (1) Reduce THC emissions (as carbon, and minus methane if you wish 
to subtract methane) by 90 percent.
    (2) Reduce methanol emissions by 90 percent.
    (3) Reduce formaldehyde emissions by 90 percent.
    (4) Limit the concentration of THC (as carbon, and minus methane if 
you wish to subtract methane) in the outlet of the add-on control 
system to 20 parts per million by volume, dry basis (ppmvd).
    (5) Limit the concentration of methanol in the exhaust from the 
add-on control system to 1 ppmvd (can be used only if the concentration 
of methanol entering the control device is greater than or equal to 10 
ppmvd).
    (6) Limit the concentration of formaldehyde in the exhaust from the 
add-on control system to 1 ppmvd (can be used only if the concentration 
of formaldehyde entering the control device is greater than or equal to 
10 ppmvd).
    In the first three options ((1) through (3)), the 90 percent 
control efficiency represents a total control efficiency. Total control 
efficiency is defined as the product of the capture efficiency and the 
control device efficiency. For process units such as rotary strand 
dryers, capture efficiency is not an issue because the rotary strand 
dryer has a single exhaust point which is easily captured by the 
control device. However, for presses and board coolers, the HAP 
emissions cannot be completely captured without installing an 
enclosure. If the enclosure meets the criteria for a wood products 
enclosure as defined in Sec.  63.2292 in today's final rule, then you 
would assign the enclosure a capture efficiency of 100 percent. You 
must test other enclosures to determine capture efficiency using EPA 
Test Methods 204 and 204A through 204F (as appropriate) found in 40 CFR 
part 51, appendix M, or the alternative tracer gas procedure in 
appendix A to today's final rule. For the three concentration options 
((4) through (6)), you must have an enclosure that either meets the 
criteria for a wood products enclosure or achieves a capture efficiency 
greater than or equal to 95 percent.
    The six compliance options are equivalent ways to express the HAP 
control levels that represent the MACT floor. Because the compliance 
options are equivalent for controlling HAP emissions, you are required 
to meet only

[[Page 45950]]

one of the six compliance options for add-on control systems. However, 
you must designate in your permit which one of the six options you have 
selected for the affected process unit. If you plan to operate a given 
process unit under different conditions, you may incorporate multiple 
compliance options for the add-on control system into your permit, as 
long as each separate operating condition is identified along with the 
compliance option that corresponds to that operating condition.
3. Emissions Averaging Compliance Option
    Emissions averaging is a means of achieving the required emissions 
reductions in a less costly way. Therefore, if you operate an existing 
affected source, for each process unit you could choose to comply with 
the emissions averaging provisions instead of the production-based 
compliance options or add-on control system compliance options.
    Emissions averaging is a system of debits and credits in which the 
credits must equal or exceed the debits. ``Debit-generating process 
units'' are the PCWP process units that are required to meet the 
control requirements but that you choose to either not control or 
under-control. ``Credit-generating process units'' are the PCWP process 
units that you choose to control that are not required to be controlled 
under the standards. When determining your actual mass removal (AMR) of 
HAP, you may include partial credits generated from debit-generating 
process units that are under-controlled (e.g., you may receive credit 
for 25 percent control of a debit-generating process unit). Control 
devices used for credit-generating process units may not be assigned 
more than 90 percent control efficiency.
    Under the emissions averaging provisions, you would determine the 
required mass removal (RMR) of total HAP from debit-generating process 
units for a 6-month compliance period. Total HAP is defined in today's 
final rule to include acetaldehyde, acrolein, formaldehyde, methanol, 
phenol, and propionaldehyde. The RMR would be based on initial total 
HAP measurements for each debit-generating process unit, your process 
unit operating hours for a 6-month period, and the required 90 percent 
control system efficiency. One hundred percent of the RMR for debit-
generating process units would have to be achieved or exceeded by the 
AMR of total HAP achieved by credit-generating process units. The AMR 
is determined based on initial performance tests, the total HAP removal 
efficiency (not to exceed 90 percent) of the control systems used to 
control the credit-generating process units, and your process unit 
operating hours over the 6-month period.
    There are some restrictions on use of the emissions averaging 
provisions in today's final rule. You must limit emissions averaging to 
the process units located within your affected source. Emissions 
averaging may not be used at new affected sources. You may not include 
in an emissions average those process units that are not operating or 
that are shut down. Only PCWP process units using add-on control 
systems may be used to generate credits.

D. What Operating Requirements Are in the Final Rule?

    The operating requirements in today's final rule apply to add-on 
control systems used to comply with the final rule and to process units 
meeting the final production-based compliance options or emissions 
averaging provisions without an add-on control device (e.g., debit-
generating process units). For incineration-based control devices and 
biofilters, the final rule specifies that you must either monitor 
operating parameters or use a THC continuous emission monitoring system 
(CEMS) to demonstrate continuous compliance. The final operating 
requirements are summarized below:
     If you operate a thermal oxidizer, such as a regenerative 
thermal oxidizer (RTO), you must maintain the firebox temperature at a 
level that is greater than or equal to the minimum temperature 
established during the performance test. If you operate a combustion 
unit that accepts process exhaust into the flame zone, you are exempt 
from the testing and monitoring requirements described above for 
thermal oxidizers.
     If you operate a catalytic oxidizer, such as a 
regenerative catalytic oxidizer (RCO) or thermal catalytic oxidizer 
(TCO), you must maintain the average catalytic oxidizer temperature at 
or above the minimum temperature established during the performance 
test. You must also check the activity level of a representative sample 
of the catalyst at least every 12 months.
     If you operate a biofilter, you must maintain the average 
biofilter bed temperature within the range you develop during the 
initial performance test or during qualifying previous performance 
tests using the required test methods. If you use values from previous 
performance tests to establish the operating parameter ranges, you must 
certify that the biofilter and associated process unit(s) have not been 
modified subsequent to the date of the performance tests.
     If you operate an add-on control system not listed in 
today's final rule, you must establish operating parameters to be 
monitored and parameter values that represent your operating 
requirements during the performance test, subject to prior written 
approval by the Administrator.
     If you operate a process unit that meets the production-
based compliance options or a process unit that generates debits in an 
emissions average without an add-on control device, you must maintain 
on a daily basis the process unit controlling operating parameter(s) 
within the ranges established during the performance test corresponding 
to the representative operating conditions identified during the 
performance test.
     As an alternative to monitoring the operating parameters 
specified above for thermal oxidizers, catalytic oxidizers, biofilters, 
other control devices, and process units that meet compliance options 
without add-on control systems, you may monitor THC concentration in 
the outlet stack with a THC CEMS. If you select this option, you must 
maintain the outlet THC concentration below the maximum concentration 
established during the performance test. You may choose to subtract 
methane from the THC concentration measured by the CEMS if you wish to 
do so.

E. What Are the Work Practice Requirements?

    The work practice requirements in today's final rule apply to 
softwood veneer dryers, dry rotary dryers, veneer redryers, hardwood 
veneer dryers, and group 1 miscellaneous coating operations. For 
softwood veneer dryers, the work practice requirements require you to 
minimize fugitive emissions from the veneer dryer doors (by applying 
appropriate operation and maintenance procedures) and from the green 
end of the dryers (through proper balancing of hot zone exhausts). For 
group 1 miscellaneous coating operations, the work practice 
requirements specify that you must use a non-HAP coating. The work 
practice requirements also specify parameters that you must monitor to 
demonstrate that each dry rotary dryer, veneer redryer, and hardwood 
veneer dryer continuously operates in a manner consistent with the 
definitions of these process units provided in today's final rule, as 
follows:
     If you operate a dry rotary dryer, you must maintain the 
inlet dryer temperature at or below 600[deg]F and maintain the moisture 
content of the wood particles entering the dryer at or below 30 weight 
percent, on a dry basis.

[[Page 45951]]

     If you operate a veneer redryer, you must maintain the 
moisture content of the wood veneer entering the dryer at or below 25 
percent, by weight.
     If you operate a hardwood veneer dryer, you must process 
less than 30 percent, by volume, softwood species each year.

F. When Must I Comply With the Final Rule?

    Existing PCWP facilities must comply within 3 years of September 
28, 2004. New sources that commence construction after January 9, 2003, 
must comply immediately upon initial startup or on September 28, 2004, 
whichever is later.
    Existing sources that wish to be included in the delisted low-risk 
subcategory must receive EPA approval of their eligibility 
demonstrations no later than 3 years after September 28, 2004, or be in 
compliance with the final rule. New sources that wish to be included in 
the delisted low-risk subcategory must receive EPA approval of their 
eligibility demonstrations no later than initial startup or on 
September 28, 2004, which ever is later, or be in compliance with the 
final rule.

G. How Do I Demonstrate Initial Compliance With the Final Rule?

    The initial compliance requirements in today's final rule vary with 
the different compliance options.
1. Production-Based Compliance Options
    If you are complying with the PBCO in today's final rule, you must 
conduct an initial performance test using specified test methods to 
demonstrate initial compliance. You must test the efficiency of your 
emissions capture device during the initial performance test if the 
process unit is a press or board cooler. The actual emission rate of 
the press or board cooler is equivalent to the measured emissions 
divided by the capture efficiency. You must test prior to any wet 
control device operated on the process unit. During the performance 
test, you must identify the process unit controlling parameter(s) that 
affect total HAP emissions; these parameters must coincide with the 
representative operating conditions you describe in the performance 
test. For each parameter, you must specify appropriate monitoring 
methods and monitoring frequencies, and for continuously monitored 
parameters, you must specify averaging times not to exceed 24 hours. 
You must install process monitoring equipment or establish 
recordkeeping procedures to be used to demonstrate compliance with the 
operating requirements for the parameters you select. During the 
initial performance test, you must use the process monitoring equipment 
or recordkeeping procedures to establish the parameter value (e.g., 
maximum, minimum, average, or range, as appropriate) that represents 
your operating requirement for the process unit. Alternatively, you may 
install a THC CEMS and monitor the process unit outlet THC 
concentration and establish your THC operating requirement during the 
performance test.
2. Add-On Control System Compliance Options
    If you use the compliance options for add-on control systems, you 
must conduct an initial performance test using specified test methods 
to demonstrate initial compliance. With the exception of the 20 ppmvd 
THC concentration option, you must test at both the inlet and the 
outlet of the HAP control device. For HAP-altering controls in 
sequence, such as a wet control device followed by a thermal oxidizer, 
you must test at the functional inlet of the control sequence (e.g., 
prior to the wet control device) and at the outlet of the control 
sequence (e.g., thermal oxidizer outlet). If you use a wet control 
device as the sole means of reducing HAP emissions, you must develop 
and implement a plan to address how organic HAP captured in the 
wastewater from the wet control device is contained or destroyed to 
minimize re-release to the atmosphere such that the desired emission 
reduction is obtained. If you use any of the six compliance options for 
add-on control systems, and the process unit is a press or a board 
cooler without a wood products enclosure, you must also test the 
capture efficiency of your partial wood products enclosure. Prior to 
the initial performance test, you must install control device parameter 
monitoring equipment or THC CEMS to be used to demonstrate compliance 
with the operating requirements for add-on control systems in today's 
final rule. During the initial performance test, you must use the 
control device parameter monitoring equipment or THC CEMS to establish 
the parameter values that represent your operating requirements for the 
control systems. If your add-on control system is preceded by a 
particulate control device (e.g., baghouse or wet electrostatic 
precipitators (WESP)), you must establish operating parameter values 
for the HAP control system and not for the particulate control device. 
If your control device is a biofilter, then you may use values recorded 
during previous performance tests for the biofilter to establish your 
operating requirements as long as you were in compliance with the 
emission limits in today's final rule when the data were collected, the 
test data were obtained using the test methods in today's final rule, 
and no modifications were made to the process unit or biofilter 
subsequent to the date of the performance tests.
3. Emissions Averaging Compliance Option
    If you elect to comply with the emissions averaging compliance 
option in today's final rule, you must submit an Emissions Averaging 
Plan (EAP) to the Administrator for approval. The EAP must describe the 
process units you are including in the emissions average. The plan also 
must specify which process units will be credit-generating units 
(including under-controlled, debit-generating process units that also 
generate credits) and which process units will be debit-generating 
units. The EAP must also include descriptions of the control systems 
used to generate emission credits, documentation of the total HAP 
measurements made to determine the RMR, calculations and supporting 
documentation to demonstrate that the AMR will be greater than or equal 
to the RMR, and a summary of the operating parameters that will be 
monitored.
    Following approval of your EAP, you must conduct performance tests 
to determine the total HAP emissions from all process units included in 
the EAP. The credit-generating process units must be equipped with add-
on control systems; therefore, for those process units, you must follow 
the procedures for demonstrating initial compliance as outlined above 
for add-on control systems. For debit-generating process units without 
air pollution control devices (APCD), you must follow the same 
procedure for establishing your operating requirements as outlined 
above for process units meeting the PBCO. The emissions averaging 
provisions require you to conduct all total HAP measurements and 
performance test(s) when the process units are operating under 
representative operating conditions. Today's final rule defines 
``representative operating conditions'' as those conditions under which 
the process unit will typically be operating following the compliance 
date. Representative conditions include such things as using a 
representative range of materials (e.g., wood material of a typical 
species mix and moisture content, typical resin formulations) and

[[Page 45952]]

operating the process unit at typical operating temperature ranges.
4. Work Practice Requirements
    The work practice requirements in today's final rule do not require 
you to conduct any initial performance tests. To demonstrate initial 
compliance with the work practice requirements for dry rotary dryers, 
you must install parameter monitoring devices to continuously monitor 
the dryer inlet operating temperature and the moisture content (dry 
basis) of the wood furnish (i.e., wood fibers, particles, or strands 
used for making board) entering the dryer. You must then use the 
parameter monitoring devices to continuously monitor and record the 
dryer temperature and wood furnish moisture content for a minimum of 30 
days. If the monitoring data indicate that during the minimum 30-day 
demonstration period, your dry rotary dryer continuously processed wood 
furnish with an inlet moisture content less than or equal to 30 
percent, and the dryer was continuously operated at an inlet dryer 
temperature less than or equal to 600[deg]F, then your dryer meets the 
definition of a dry rotary dryer in today's final rule. You must submit 
the monitoring data as part of your notification of compliance status 
report.
    To demonstrate initial compliance with the work practice 
requirements for hardwood veneer dryers, you must calculate the 
annualized percentage of softwood veneer processed in the dryer by 
volume, using veneer dryer production records for the 12-month period 
prior to the compliance date. If the total annual percentage by volume 
of softwood veneer is less than 30 percent, your veneer dryer meets the 
definition of hardwood veneer dryer. You must then submit a summary of 
the production data for the 12-month period and a statement verifying 
that the veneer dryer will continue to process less than 30 percent 
softwoods as part of your notification of compliance status report.
    To demonstrate initial compliance with the work practice 
requirements for softwood veneer dryers, you must develop a plan for 
minimizing fugitive emissions from the veneer dryer green end and 
heated zones. You must submit the plan with your notification of 
compliance status report.
    To demonstrate initial compliance with the work practice 
requirements for veneer redryers, you must install a device that can be 
used to continuously monitor the moisture content (dry basis) of veneer 
entering the dryer. You must then use the moisture monitoring device to 
continuously monitor and record the inlet moisture content of the 
veneer for a minimum of 30 days. If the monitoring data indicate that 
your veneer dryer continuously processed veneer with a moisture content 
less than or equal to 25 percent during the minimum 30-day 
demonstration period, then your veneer dryer meets the definition of a 
veneer redryer in today's final rule. You must submit the monitoring 
data as part of your notification of compliance status report.
    To demonstrate initial compliance with the work practice 
requirement for group 1 miscellaneous coating operations, you must 
submit a signed statement with your notification of compliance status 
report stating that you are using non-HAP coatings. You must also have 
a record (e.g., material safety data sheets) showing that you are using 
non-HAP coatings as defined in today's final rule.

H. How Do I Demonstrate Continuous Compliance With the Final Rule?

    The continuous compliance requirements in today's final rule vary 
with the different types of compliance options.
1. Production-Based Compliance Options
    If you comply with the PBCO, then you must monitor and/or record 
the controlling operating parameter(s) identified as affecting total 
HAP emissions from the process unit(s) in the performance test. For 
each parameter, you must use the monitoring methods, monitoring 
frequencies, and averaging times (for continuously monitored parameters 
not to exceed 24 hours) specified in your performance test and 
Notification of Compliance Status. For each operating parameter, you 
must maintain on a daily basis the parameter at or above the minimum, 
at or below the maximum, or within the range (whichever applies) 
established during the performance test.
    Instead of monitoring process operating parameters, you may operate 
a CEMS for monitoring THC concentration to demonstrate compliance with 
the operating requirements in today's final rule. If you choose to 
operate a THC CEMS in lieu of a continuous parameter monitoring systems 
(CPMS), you must demonstrate continuous compliance, as described in the 
following subsection.
2. Add-On Control System Compliance Options
    For add-on control systems, you must install a CPMS to monitor the 
temperature or install a CEMS to monitor THC concentration to 
demonstrate compliance with the operating requirements in today's final 
rule. If you operate a CPMS, you must have at least 75 percent of the 
required recorded readings for each 3-hour or 24-hour block averaging 
period to calculate the data averages. You must operate the CPMS at all 
times the process unit is operating. You must also conduct proper 
maintenance of the CPMS and maintain an inventory of necessary parts 
for routine repairs of the CPMS. Using the data collected with the 
CPMS, you must calculate and record the average values of each 
operating parameter according to the specified averaging times.
    For thermal oxidizers, you must continuously maintain the 3-hour 
block average firebox temperature at or above the minimum temperature 
established during the performance test. For catalytic oxidizers, you 
must continuously maintain the 3-hour block average catalytic oxidizer 
temperature at or above the minimum value established during the 
performance test. You must also check the activity level of a 
representative sample of the catalyst at least every 12 months and take 
any necessary corrective action to ensure that the catalyst is 
performing within its design range.
    For biofilters, you must continuously maintain the 24-hour block 
average biofilter bed temperature within the operating range you 
establish during the performance test. You must also conduct a repeat 
performance test using the applicable method(s) within 2 years 
following the previous performance test and within 180 days after each 
replacement of any portion of the biofilter bed with a different media 
or each replacement of more than 50 percent (by volume) of the 
biofilter bed media with the same type of media.
    If you choose to operate a CEMS for monitoring THC concentration 
instead of operating a CPMS, you must install, operate, and maintain 
the CEMS according to Performance Specification 8 in 40 CFR part 60, 
appendix B. You must also comply with the CEMS data quality assurance 
requirements in Procedure 1 of appendix F of 40 CFR part 60. You must 
conduct a performance evaluation of the CEMS according to 40 CFR 63.8 
and Performance Specification 8. The CEMS must complete a minimum of 
one cycle of operation (sampling, analyzing, and data recording) for 
each successive 15-minute period. Using the data collected with the 
CEMS, you must calculate and record the 3-hour block average THC 
concentration for thermal or catalytic oxidizers. For biofilters, you 
must calculate and record the 24-hour block

[[Page 45953]]

average THC concentration. You must continuously monitor and maintain 
the 24-hour block average THC concentration at or below the maximum 
established during the performance test. You may use a CEMS that 
subtracts methane from the measured THC concentration if you wish to do 
so.
    If you comply with today's final rule using an add-on control 
system, you may request a routine control device maintenance exemption 
from the Administrator. Your request for a routine control device 
maintenance exemption must document the need for routine maintenance on 
the control device and the time required to accomplish the maintenance, 
describe the maintenance activities and the frequency of these 
activities, explain why the maintenance cannot be accomplished during 
process shutdowns, describe how you plan to make reasonable efforts to 
minimize emissions during these maintenance activities, and provide any 
other documentation required by the Administrator. If your request for 
the routine control device maintenance exemption is approved by the 
Administrator, it must be incorporated into your title V permit. The 
compliance options and operating requirements would not apply during 
times when control device maintenance covered under your approved 
routine control device maintenance exemption is performed. The routine 
control device maintenance exemption may not exceed 3 percent of annual 
operating uptime for each green rotary dryer, tube dryer, rotary strand 
dryer, or pressurized refiner controlled. The routine control device 
maintenance exemption is limited to 0.5 percent of the annual operating 
uptime for each softwood veneer dryer, reconstituted wood product 
press, reconstituted wood product board cooler, hardboard oven, press 
predryer, conveyor strand dryer, or fiberboard mat dryer controlled. If 
your control device is used to control a combination of equipment with 
different downtime allowances (e.g., a tube dryer and a press), then 
the highest (i.e., 3 percent) downtime allowance applies.
3. Emissions Averaging Compliance Option
    To demonstrate continuous compliance with the emissions averaging 
provisions, you must continuously comply with the applicable operating 
requirements for add-on control systems (described in the previous 
subsection). You also must maintain records of your operating hours for 
each process unit included in the EAP. For each semiannual compliance 
period, you must demonstrate that the AMR equals or exceeds the RMR 
using your initial (or most recent) total HAP measurements for debit-
generating units, initial (or most recent) performance test results for 
credit-generating units, and the operating hours recorded for the 
semiannual compliance period.
4. Work Practice Requirements
    To demonstrate continuous compliance with the work practice 
requirements for dry rotary dryers and veneer redryers, you must 
operate all dry rotary dryers and veneer redryers so that they 
continuously meet the definitions of these process units in today's 
final rule. For dry rotary dryers, you must continuously monitor and 
maintain the inlet furnish moisture content at or below 30 percent and 
the inlet dryer operating temperature at or below 600[deg]F. You must 
also calibrate the moisture monitor based on the procedures specified 
by the moisture monitor manufacturer at least once per semiannual 
compliance period to verify the readings from the moisture meter. For 
veneer redryers, you must continuously monitor and maintain the inlet 
veneer moisture content at or below 25 percent.
    To demonstrate continuous compliance with the work practice 
requirements for softwood veneer dryers, you must follow the procedures 
in your operating plan for minimizing fugitive emissions from the green 
end and heated zones of the veneer dryer and maintain records 
documenting that you have followed your plan. For hardwood veneer 
dryers, you must continue to process less than 30 percent softwood 
veneer by volume and maintain records on veneer dryer production.
    To demonstrate continuous compliance with the work practice 
requirements for group 1 miscellaneous coating operations, you must 
keep records showing that you continue to use non-HAP coatings as 
defined in the final rule.

I. How Do I Demonstrate That My Affected Source Is Part of the Low-Risk 
Subcategory?

    For your affected source to be part of the delisted low-risk 
subcategory, you must have a low-risk demonstration approved by EPA, 
and you must then have federally enforceable conditions reflecting the 
parameters used in your EPA-approved demonstration incorporated into 
your title V permit to ensure that your affected source remains low-
risk. Low-risk demonstrations for eight facilities were conducted by 
EPA, and no further demonstration is required for them. They will, 
however, need to obtain title V permit terms reflecting their status. 
(We will provide these sources and their title V permitting authorities 
with the necessary parameters for establishing corresponding permit 
terms and conditions.) These facilities are listed in Table 2 to this 
preamble. Other facilities may demonstrate to EPA that their PCWP 
affected source is low risk by using the look-up tables in appendix B 
to 40 CFR part 63, subpart DDDD or conducting a site-specific risk 
assessment as specified in appendix B to subpart DDDD. Appendix B to 
subpart DDDD also specifies which process units and pollutants must be 
included in your low-risk demonstration, emissions testing methods, the 
criteria for determining if an affected source is low risk, risk 
assessment methodology (look-up table analysis or site-specific risk 
analysis), contents of the low-risk demonstration, schedule for 
submitting and obtaining approval of your low-risk demonstration, and 
methods for ensuring that your affected source remains in the low-risk 
subcategory. If you demonstrate that your affected source is part of 
the delisted low-risk subcategory of PCWP manufacturing facilities, 
then your affected source is not subject to the MACT compliance 
options, operating requirements, and work practice requirements in the 
final PCWP rule (subpart DDDD).
1. Low-Risk Criteria
    We may approve your affected source as eligible for membership in 
the delisted low-risk subcategory of PCWP sources if we determine that 
it is low risk for both carcinogenic and noncarcinogenic effects. To be 
considered low risk, the PCWP affected source must meet the following 
criteria: (1) The maximum off-site individual lifetime cancer risk at a 
location where people live is less than one in one million for 
carcinogenic chronic inhalation effects; (2) every maximum off-site 
target-organ specific hazard index (TOSHI) (or, alternatively, an 
appropriately site-specific set of 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 your affected source's 
HAP mixture) at a location where people live is less than or equal to 
1.0 for noncarcinogenic chronic inhalation effects; and (3) the maximum 
off-site acute hazard quotients for acrolein and formaldehyde are less 
than or equal to 1.0 for

[[Page 45954]]

noncarcinogenic acute inhalation effects. These criteria are built into 
the look-up tables included in appendix B to subpart DDDD. Facilities 
conducting site-specific risk assessments must explicitly demonstrate 
that they meet these criteria. Facilities need not perform site-
specific multipathway human health risk assessments or ecological risk 
assessments since EPA performed a source category-wide screening 
assessment which demonstrates that these risks are insignificant for 
all sources.
2. PCWP Affected Sources Delisted in Today's Action
    Eight PCWP affected sources are being delisted today as part of the 
low-risk subcategory. They are listed below in Table 2 of this 
preamble. If your affected source is part of the low-risk subcategory 
and you do not wish it to remain in the subcategory, you may notify us, 
in writing, and we will remove your affected source from the low-risk 
subcategory. Any affected sources removed from the low-risk subcategory 
are subject to the requirements of subpart DDDD, as applicable. Please 
address your written notification to Ms. Mary Tom Kissell (see FOR 
FURTHER INFORMATION CONTACT section).

Table 2. -- Low - Risk Affected Sources in the Low-Risk PCWP Subcategory
------------------------------------------------------------------------
        Name of Affected Source                      Location
------------------------------------------------------------------------
Georgia-Pacific Plywood Plant..........  Monroeville, AL.
Georgia-Pacific--Hawthorne Plywood Mill  Hawthorne, FL.
Oregon Panel Products (Lebanite).......  Lebanon, OR.
Hardel Mutual Plywood Corporation......  Chehalis, WA.
Hood Industries, Incorporated..........  Wiggins, MS.
Plum Creek Manufacturing, LP...........  Kalispell, MT.
Potlatch Corporation--St. Maries         St. Maries, ID.
 Plywood.
SierraPine Limited, Rocklin MDF........  Rocklin, CA.
------------------------------------------------------------------------

    We performed a risk assessment to determine the magnitude of 
potential chronic human cancer and noncancer risks and the potential 
for acute noncancer risks and adverse environmental impacts associated 
with the sources in the PCWP source category. The risk assessment was 
performed for 181 of the 223 major PCWP affected sources. Affected 
sources where available location data were ambiguous or where all of 
their site-specific information was requested to be treated as 
confidential were excluded from the analysis, leaving a total of 181 
affected sources in the assessment. For the risk assessment, we used 
our baseline emission estimates (developed using average emission 
factors and, if available, site-specific process throughput data) and 
model PCWP emissions release characteristics as inputs into our Human 
Exposure Model (HEM) to generate cancer and non-cancer risk estimates 
for the 181 PCWP affected sources. The risk assessment methodology is 
explained in detail in the supporting information for this final rule.
    Because our risk estimates include model emissions release 
information, they are not as rigorous as the risk demonstrations we are 
requiring PCWP affected sources to perform. Therefore, to ensure the 
affected sources listed in Table 2 of this preamble meet the low risk 
criteria in appendix B to subpart DDDD, we subjected them to more 
stringent standards than required for risk demonstrations based on 
better (i.e., site-specific) data. First, we increased the level of 
protection to human health by a factor of 10. Instead of using the 
criteria established in appendix B to subpart DDDD of one in 1 million 
risk for cancer and TOSHI of less than or equal to 1.0, PCWP affected 
sources with cancer risk greater than 0.1 in 1 million or a TOSHI 
greater than 0.1 were excluded. For the remaining PCWP affected 
sources, we estimated emission factors based on the highest emissions 
test data we had. We remodeled these PCWP affected sources using worst-
case (i.e. highest) emission factors and the January 2004 IRIS cancer 
URE for formaldehyde. From this analysis, affected sources with hazard 
index values greater than 0.2 or cancer risks greater than one in 1 
million were excluded. Of the remaining affected sources, we eliminated 
those that are closed, have pending enforcement actions, and that did 
not submit or claimed as confidential site-specific throughput data. We 
also consulted with an industry trade association and they removed 
various affected sources from the list for various reasons.
3. Determining HAP Emissions From the Affected Source
    You must include in your low-risk demonstration every process unit 
within the PCWP affected source that emits one or more of the following 
HAP: acetaldehyde, acrolein, arsenic, benzene, beryllium, cadmium, 
chromium, formaldehyde, lead, MDI, manganese, nickel, and phenol. You 
must conduct emissions testing using the methods specified in appendix 
B to subpart DDDD. For reconstituted wood product presses or 
reconstituted wood product board coolers, you must determine the 
capture efficiency of the capture device. If you use a control device 
for purposes of demonstrating that your affected source is part of the 
low-risk subcategory, then you must collect monitoring data and 
establish operating limits for the control system using the same 
methods specified in subpart DDDD.
4. Low-Risk Demonstrations
    Once you have conducted emissions testing, you may perform a lookup 
table analysis or site-specific risk analysis. Regardless of the type 
of risk analysis used, you must use the most recent EPA-approved dose-
response values as posted on our Air Toxics Website at http://www.epa.gov/ttn/atw/toxsource/summary.html to demonstrate that your 
affected source may be part of the low-risk subcategory. If you can 
demonstrate that your affected source is low-risk based on the look-up 
table analysis, then you need not complete a site-specific risk 
analysis. If your affected source is not low-risk based on the look-up 
table analysis, then you may elect to proceed with site-specific risk 
analysis. Appendix B to subpart DDDD specifies what your low-risk 
demonstration must contain.
    Look-up table analysis. You may use the look-up tables (Tables 3 
and 4 to 40 CFR part 63, subpart DDDD, appendix B) to determine if your 
affected source may be part of the low-risk subcategory. Table 3 to 
appendix B to subpart DDDD provides the maximum allowable toxicity-
weighted carcinogen emission rate, and Table 4 to appendix B to subpart 
DDDD provides the maximum allowable toxicity-weighted noncarcinogen 
emission rate that your affected source can emit. To use the look-up 
tables, you must determine your toxicity-weighted carcinogen and 
noncarcinogen emission rates using the equations in appendix B to 
subpart DDDD; the average stack height of all PCWP emission points at 
your affected source; and the minimum distance from any emission point 
to the nearest property boundary. If the total toxicity-weighted 
carcinogen and noncarcinogen emission rates for your affected source 
are less than or equal to the values in both look-up tables, then EPA 
may approve your affected source as part of the low-risk subcategory of 
PCWP affected sources.
    Site-specific risk assessment. You may use any scientifically-
accepted peer-reviewed risk assessment methodology to demonstrate to 
EPA that

[[Page 45955]]

your affected source may be low risk. An example 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 Reference Library.'' However, this approach may not be 
appropriate for all affected sources, and EPA may require that any 
specific affected source use an alternative approach. You may obtain a 
copy of the ``Air Toxics Risk Assessment Reference Library, Volume 2, 
Site-Specific Risk Assessment Technical Resource Document'' through 
EPA's air toxics website at www.epa.gov/ttn/atw.
    For EPA to approve your low-risk demonstration, you must 
demonstrate that: (1) The maximum off-site individual lifetime cancer 
risk at a location where people live is less than one in one million 
for carcinogenic chronic inhalation effects; (2) every maximum off-site 
TOSHI at a location where people live is less than or equal to 1.0 for 
non-carcinogenic chronic inhalation effects; and (3) the maximum off-
site acute hazard quotients for acrolein and formaldehyde are less than 
or equal to 1.0 for noncarcinogenic acute inhalation effects.
5. When Must I Submit Risk Demonstrations to EPA?
    You must submit your low-risk demonstration to EPA for approval. If 
you have an existing affected source, you must submit your low-risk 
demonstration no later than July 31, 2006. To facilitate the review and 
approval process, EPA encourages facilities to submit their assessments 
as soon as possible. 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 the effective date of subpart 
DDDD, then you must complete and submit for EPA approval your low-risk 
demonstration no later than July 31, 2006. 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 the 
effective date of subpart DDDD, then you must complete and submit for 
approval your low-risk demonstration no later than 12 months after you 
become a major source or after initial startup of your affected source 
as a major source, whichever is later.
    If you have a new or reconstructed affected source you must conduct 
the emission tests upon initial startup and use the results of these 
emissions tests to complete and submit your low-risk demonstration 
within 180 days following your initial startup date. If your new or 
reconstructed affected source starts up before the effective date of 
subpart DDDD, for EPA to find that you are included in the low-risk 
subcategory, your low-risk demonstration must show that you were 
eligible for the low-risk subcategory no later than the effective date 
of subpart DDDD. If your new or reconstructed source starts up after 
the effective date of subpart DDDD, for EPA to find that you are 
included in the low-risk subcategory, your low-risk demonstration must 
show that you were eligible for the low-risk subcategory upon initial 
startup of your affected source.
    Affected sources that are not part of the low-risk subcategory 
within 3 years after the effective date of subpart DDDD must comply 
with the requirements of 40 CFR part 63, subpart DDDD. Facilities may 
not request compliance extensions from the permitting authority if they 
fail to demonstrate they are part of the low-risk subcategory or to 
request additional time to install controls to become part of the low-
risk subcategory. All approved low risk sources must then obtain title 
V permit revisions including terms and conditions reflecting the 
parameters used in their approved demonstrations, according to the 
schedules in their applicable part 70 or part 71 title V permit 
programs.
6. Remaining in the Low-Risk Subcategory
    You must ensure that your affected source is low risk by 
periodically certifying your affected source is low risk, monitoring 
applicable HAP control device parameters, and by maintaining certain 
records. 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. Your certification must consider process 
changes that increase HAP emissions, population shifts, and changes to 
dose-response values. If your affected source commences operating 
outside of the low-risk subcategory, it is no longer part of the low-
risk subcategory. 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. You must be 
in compliance with all of the applicable requirements of 40 CFR part 
63, subpart DDDD beginning on the date when your affected source 
commences operating outside the low-risk subcategory if you had a 
process change that increases HAP emissions. If you are operating 
outside of the low-risk subcategory due to a population shift or change 
to dose-response values, then you must comply with all of the 
applicable requirements of 40 CFR part 63, subpart DDDD no later than 
three years from the date your affected source commences operating 
outside the low-risk subcategory.

III. Summary of Environmental, Energy, and Economic Impacts

A. How Many Facilities Are Impacted by the Final Rule?

    Facilities with estimated potential to emit 25 tons or more of 
total HAP or 10 or more tons of an individual HAP are major sources of 
HAP and are subject to the final rule. Approximately 223 PCWP major 
source facilities nationwide are expected to meet the applicability 
criteria defined in today's final rule. These major source facilities 
generally manufacture one or more of the following products: Softwood 
plywood, softwood veneer, medium density fiberboard (MDF), oriented 
strandboard (OSB), particleboard, hardboard, laminated strand lumber, 
and laminated veneer lumber. However, only 212 of these facilities have 
equipment that is subject to the control requirements of the final 
rule. In addition, there are approximately 34 major source sawmill 
facilities that produce kiln-dried lumber; although these major source 
sawmill facilities meet the applicability criteria in the final rule, 
there are no control requirements for any of the equipment located at 
the sawmills.
    The number of impacted facilities was determined based on the 
estimated potential to emit (i.e., uncontrolled HAP emissions) from 
each facility, whether each facility has any process units subject to 
the compliance options, whether or not the facility already operates 
control systems necessary to meet the final rule, and whether or not 
the affected source is currently eligible (or may later demonstrate 
eligibility) for inclusion in the delisted low risk subcategory. Of the 
223 major source facilities, an estimated 162 are expected to install 
add-on control systems to reduce emissions. The remaining facilities 
already have installed add-on controls, do not have any process units 
subject to the compliance options, are expected to comply with work 
practice requirements only, or are one of the eight facilities 
currently eligible for inclusion in the delisted low-risk subcategory. 
We estimate that eventually as many as 147 of the 223 major source PCWP 
facilities may demonstrate eligibility for the low-risk subcategory, 
leaving 58 facilities expected to install add-on control systems to 
reduce emissions. Some of the 147 facilities expected to eventually

[[Page 45956]]

be included the low-risk subcategory were not expected to install 
controls to meet MACT because they either already have the necessary 
controls or do not have process units subject to the compliance options 
in today's final rule.
    The environmental and cost impacts presented in this preamble 
represent the estimated impacts for the range of facilities, from 58 
facilities estimated to be impacted following completion of eligibility 
demonstrations for the low-risk subcategory, to 162 facilities 
estimated to be impacted today. The impact estimates were based on the 
use of RTO (or in some cases a combination WESP and RTO) because RTO 
are the most prevalent HAP emissions control technology used in the 
PCWP industry. However, technologies other than RTO could be used to 
comply with today's final rule. For a facility that we feel already 
achieves the emissions reductions required by today's final rule, only 
testing, monitoring, reporting and recordkeeping cost impacts were 
estimated.

B. What Are the Air Quality Impacts?

    We estimate nationwide baseline HAP emissions from the PCWP source 
category to be 17,000 Mg/yr (19,000 tons/yr) at the current level of 
control. We estimate that today's final rule will reduce total HAP 
emissions from the PCWP source category by about 9,900 Mg/yr (11,000 
tons/yr). In addition, we estimate that today's final rule will reduce 
VOC emissions (approximated as THC) by about 25,000 Mg/yr (27,000 tons/
yr) from a baseline level of 45,000 Mg/yr (50,000 tons/yr). Depending 
on the number of facilities eventually demonstrating eligibility for 
the low-risk subcategory, these emission reductions could change to 
5,900 Mg/yr (6,600 tons/yr) for HAP or 13,000 Mg/yr (14,000 tons/yr) 
for VOC.
    In addition to reducing emissions of HAP and VOC, today's final 
rule will also reduce emissions of criteria pollutants, such as carbon 
monoxide (CO) from direct-fired emission sources and particulate matter 
less than 10 microns in diameter (PM10). We estimate that 
today's final rule will reduce CO emissions by about 9,500 Mg/yr 
(10,000 tons/yr). We also estimate that the final rule will reduce 
PM10 emissions by about 11,000 Mg/yr (12,000 tons/yr). 
Depending on the number of facilities eventually demonstrating 
eligibility for the low-risk subcategory, these emission reductions 
could change to 7,600 Mg/yr (8,400 tons/yr) for CO and 5,300 Mg/yr 
(5,900 tons/yr) for PM10.
    Combustion of exhaust gases in an RTO generates some emissions of 
nitrogen oxides (NOX). We estimate that the nationwide 
increase in NOX emissions due to the use of RTO will be 
about 2,100 Mg/yr (2,400 tons/yr). This estimated increase in 
NOX emissions may be an overestimate because some plants may 
select control technologies other than RTO to comply with today's final 
rule. Depending on the number of facilities eventually demonstrating 
eligibility for the low-risk subcategory, the estimated NOX 
emission increase could fall to 1,100 Mg/yr (1,200 tons/yr).
    Secondary air impacts of today's final rule could result from 
increased electricity usage associated with operation of control 
devices. The secondary air emissions of NOX, CO, 
PM10, sulfur dioxide (SO2) depend on the fuel used to 
generate electricity and on other factors. The EPA believes SO2 
emissions may not increase from electric generation since that the 
requirements of the Acid Rain trading program will keep power plants 
from increasing their SO2 emissions. Furthermore, we believe that 
NOX emissions increases from power plants may be limited. 
The EPA expects the emissions trading program that is part of the 
NOX SIP call will likely keep NOX emissions in 
the eastern United States from increasing as result of additional power 
generation to operate RTOs.

C. What Are the Water Quality Impacts?

    Wastewater is produced from WESP blowdown, washing out of RTO, and 
biofilters. We based all of our impact estimates on the use of RTO 
(with or without a WESP upstream depending on the process unit). We 
estimate that the wastewater generated from WESP blowdown and RTO 
washouts will increase by about 100,000 cubic meters per year (m\3\/yr) 
(27 million gallons per year (gal/yr)) as a result of today's final 
rule. Depending on the number of facilities eventually demonstrating 
eligibility for the low-risk subcategory, the wastewater impacts could 
fall to 90,000 cubic meters per year (m\3\/yr) (24 million gallons per 
year (gal/yr)). According to the data in our MACT survey, this 
nationwide increase in wastewater flow is within the range of water 
flow rates handled by individual facilities. Facilities would likely 
dispose of this wastewater by sending it to a municipal treatment 
facility, reusing it onsite (e.g., in log vats or resin mix), or 
hauling it offsite for spray irrigation. In addition, we are amending 
the effluent limitations, guidelines for the timber products processing 
point source category to allow facilities (on a case-by-case basis) to 
obtain a permit to discharge wastewaters from APCD installed to comply 
with today's final rule.

D. What Are the Solid Waste Impacts?

    Solid waste is produced in the form of solids from WESP and by RTO 
or RCO media replacement. We estimate that 4,500 Mg/yr (4,900 tons/yr) 
of solid waste will be generated as a result of today's final rule. 
Depending on the number of facilities eventually demonstrating 
eligibility for the low-risk subcategory, the solid waste increase 
could change to 2,800 Mg/yr (3,000 tons/yr). Some PCWP facilities have 
been able to use RTO or RCO media as aggregate in onsite roadbeds. Some 
facilities have also been able to identify a beneficial reuse for wet 
control device solids (such as giving them away to local farmers for 
soil amendment).

E. What Are the Energy Impacts?

    The overall energy demand (i.e., electricity and natural gas) is 
expected to increase by about 4.3 million gigajoules per year (GJ/yr) 
(4.1 trillion British thermal units per year (Btu/yr)) nationwide under 
today's final rule. The estimated increase in the energy demand is 
based on the electricity requirements associated with RTO and WESP and 
the fuel requirements associated with RTO. Electricity requirements are 
expected to increase by about 711 gigawatt hours per year (GWh/yr) 
under today's final rule. Natural gas requirements are expected to 
increase by about of 44 million m\3\/yr (1.6 billion cubic feet per 
year (ft\3\/yr)) under the final rule. Depending on the number of 
facilities eventually demonstrating eligibility for the low-risk 
subcategory, these energy estimates could fall to 2.3 million GJ/yr 
(2.2 trillion Btu/yr) for overall energy demand, 378 GWh/yr for the 
increase in electricity requirements, and 24 million m\3\/yr (0.9 
billion ft\3\/yr) for the increase in natural gas requirements.

F. What Are the Cost Impacts?

    The cost impacts estimated for today's final rule represent a high-
end estimate of costs. Although the use of RTO technology to reduce HAP 
emissions represents the most expensive compliance option, we based our 
nationwide cost estimates on the use of RTO technology at all of the 
impacted facilities because: (1) RTO technology can be used to reduce 
emissions from all types of PCWP process units; and (2) we could not 
accurately predict which facilities would use emissions averaging or 
PBCO or install add-on control devices that are less costly to operate, 
such as RCO and biofilters. Therefore, our cost estimates are likely to 
be

[[Page 45957]]

overstated as we anticipate that owners and operators of impacted 
sources will take advantage of available cost saving opportunities.
    The high-end estimated total capital costs of today's final rule 
are $471 million. Depending on the number of facilities eventually 
demonstrating eligibility for the low-risk subcategory, the capital 
costs could fall to $240 million. These capital costs apply to existing 
sources and include the costs to purchase and install both the RTO 
equipment (and in some cases, a WESP upstream of the RTO) and the 
monitoring equipment, and the costs of performance tests. Wood products 
enclosure costs are also included for reconstituted wood products 
presses.
    The high-end estimated annualized costs of the final standards are 
$140 million. Depending on the number of facilities eventually 
demonstrating eligibility for the low-risk subcategory, the annualized 
costs could fall to $74 million. The annualized costs account for the 
annualized capital costs of the control and monitoring equipment, 
operation and maintenance expenses, and recordkeeping and reporting 
costs. Potential control device cost savings and increased 
recordkeeping and reporting costs associated with the emissions 
averaging provisions in today's final rule are not accounted for in 
either the capital or annualized cost estimates.

G. What Are the Economic Impacts?

    The economic impact analysis shows that the expected price 
increases for affected output would range from 0.4 to 1.3 percent as a 
result of the NESHAP for PCWP manufacturers. The expected change in 
production of affected output is a reduction of 0.06 to 0.4 percent for 
PCWP manufacturers as a result of today's final rule. No plant closures 
are expected out of the 223 facilities affected by the final rule. 
Therefore, it is likely that there is no adverse impact expected to 
occur for those industries that produce output affected by the final 
rule, such as hardboard, softwood plywood and veneer, engineered wood 
products, and other wood composites.

H. What Are the Social Costs and Benefits?

    Our assessment of costs and benefits of today's final rule is 
detailed in the ``Regulatory Impact Analysis for the Proposed Plywood 
and Composite Wood Products MACT.'' The Regulatory Impact Analysis 
(RIA) is located in Docket number A-98-44 and Docket number OAR-2003-
0048.
    It is estimated that 3 years after implementation of the final rule 
requirements, reductions of formaldehyde, acetaldehyde, acrolein, 
methanol, phenol and several other HAP from existing PCWP emission 
sources would be 5,900 Mg/yr (6,600 tons/yr) to 9,900 Mg/yr (11,000 
tons/yr), depending on how many affected sources are in the low-risk 
subcategory. The health effects associated with these HAP are discussed 
earlier in this preamble.
    At this time, we are unable to provide a comprehensive 
quantification and monetization of the HAP-related benefits of the 
final rule. Nevertheless, it is possible to derive rough estimates for 
one of the more important benefit categories, i.e., the potential 
number of cancer cases avoided and cancer risk reduced as a result of 
the imposition of the MACT level of control on this source category. 
Our analysis suggests that imposition of the MACT level of control 
would reduce cancer cases by less than one case per year, on average, 
starting some years after implementation of the standards. We present 
these results in the RIA. This risk reduction estimate is uncertain and 
should be regarded as an extremely rough estimate and should be viewed 
in the context of the full spectrum of unquantified noncancer effects 
associated with the HAP reductions.
    The control technologies used to reduce the level of HAP emitted 
from PCWP sources are also expected to reduce emissions of CO, 
PM10, and VOC. Depending on how many affected sources are in 
the low-risk subcategory, it is estimated that CO emissions reductions 
total approximately 7,600 Mg/yr (8,400 tons/yr) to 9,500 Mg/yr (10,000 
tons/yr), PM10 emissions reductions total approximately 
5,300 Mg/yr (5,900 tons/yr) to 11,000 Mg/yr (12,000 tons/yr), and VOC 
emissions reductions (approximated as THC) total approximately 13,000 
Mg/yr (14,000 tons/yr) to 25,000 Mg/yr (27,000 tons/yr). These 
estimated reductions occur from existing sources in operation 3 years 
after the implementation of the requirements of the final rule and are 
expected to continue throughout the life of the sources. Human health 
effects associated with exposure to CO include cardiovascular system 
and CNS effects, which are directly related to reduced oxygen content 
of blood and which can result in modification of visual perception, 
hearing, motor and sensorimotor performance, vigilance, and cognitive 
ability. The VOC emissions reductions may lead to some reduction in 
ozone concentrations in areas in which the affected sources are 
located. There are both human health and welfare effects that result 
from exposure to ozone, and these effects are listed in Table 3 of this 
preamble.

          Table 3.--Unquantified Benefit Categories From HAP, Ozone-Related, and PM Emissions Reductions
----------------------------------------------------------------------------------------------------------------
                                       Unquantified effects      Unquantified effect       Unquantified effect
                                     categories  associated    categories  associated    categories  associated
                                            with HAP                 with ozone                  with PM
----------------------------------------------------------------------------------------------------------------
Health Categories.................  Carcinogenicity            Airway responsiveness    Premature mortality
                                    Genotoxicity............  Pulmonary inflammation..  Chronic bronchitis
                                    Pulmonary function        Increased susceptibility  Hospital admissions for
                                     decrement.                to respiratory            chronic obstructive
                                    Dermal irritation.......   infection.                pulmonary disease,
                                    Eye irritation..........  Acute inflammation and     pneumonia,
                                    Neurotoxicity...........   respiratory cell damage.  cardiovascular
                                    Immunotoxicity..........  Chronic respiratory        diseases, and asthma
                                    Pulmonary function         damage/Premature aging   Changes in pulmonary
                                     decrement.                of lungs.                 function
                                    Liver effects...........  Emergency room visits     Morphological changes
                                    Gastrointestinal effects   for asthma.              Altered host defense
                                    Kidney effects..........  Hospital admissions for    mechanisms
                                    Cardiovascular             respiratory diseases.    Cancer
                                     impairment.              Asthma attacks..........  Other chronic
                                    Hematopoietic (Blood      Minor restricted           respiratory disease
                                     disorders).               activity days.           Emergency room visits
                                    Reproductive/                                        for asthma
                                     Developmental effects.                             Lower and upper
                                                                                         respiratory symptoms
                                                                                        Acute bronchitis
                                                                                        Shortness of breath
                                                                                        Minor restricted
                                                                                         activity days
                                                                                        Asthma attacks
                                                                                        Work loss days.

[[Page 45958]]

 
Welfare Categories................  Corrosion/Deterioration   Ecosystem and vegetation  Materials damage
                                    Unpleasant odors........   effects in Class I       Damage to ecosystems
                                    Transportation safety      areas (e.g., national     (e.g., acid sulfate
                                     concerns.                 parks)                    deposition)
                                    Yield reductions/Foliar   Damage to urban           Nitrates in drinking
                                     injury.                   ornamentals (e.g.,        water.
                                    Biomass decrease........   grass, flowers, shrubs,
                                    Species richness decline   and trees in urban
                                    Species diversity          areas).
                                     decline.                 Commercial field crops..
                                    Community size decrease.  Fruit and vegetable
                                    Organism lifespan          crops.
                                     decrease.                Reduced yields of tree
                                    Trophic web shortening..   seedlings, commercial
                                                               and non-commercial
                                                               forests.
                                                              Damage to ecosystems....
                                                              Materials damage........
                                                              Reduced worker
                                                               productivity.
----------------------------------------------------------------------------------------------------------------

    At the present time, we cannot provide a monetary estimate for the 
benefits associated with the reductions in CO. We also did not provide 
a monetary estimate for the benefits associated with the changes in 
ozone concentrations that result from the VOC emissions reductions 
since we are unable to do the necessary air quality modeling to 
estimate the ozone concentration changes. For PM10 , we did 
not provide a monetary estimate for the benefits associated with the 
reduction of the emissions, although these reductions are likely to 
have significant health benefits to populations living in the vicinity 
of affected sources.
    There may be increases in NOX emissions associated with 
today's final rule as a result of increased use of incineration-based 
controls. These NOX emission increases by themselves could 
cause some increase in ozone and particulate matter (PM) 
concentrations, which could lead to impacts on human health and welfare 
as listed in Table 3 of this preamble. The potential impacts associated 
with increases in ambient PM and ozone due to these emission increases 
are discussed in the RIA. In addition to potential NOX 
increases at affected sources, today's final rule may also result in 
additional electricity use at affected sources due to application of 
controls. As such, the final rule may result in additional health 
impacts from increased ambient PM and ozone from these increased 
utility emissions. We did not quantify or monetize these health 
impacts.
    Every benefit-cost analysis examining the potential effects of a 
change in environmental protection requirements is limited to some 
extent by data gaps, limitations in model capabilities (such as 
geographic coverage), and uncertainties in the underlying scientific 
and economic studies used to configure the benefit and cost models. 
Deficiencies in the scientific literature often result in the inability 
to estimate changes in health and environmental effects. Deficiencies 
in the economics literature often result in the inability to assign 
economic values even to those health and environmental outcomes which 
can be quantified. These general uncertainties in the underlying 
scientific and economics literatures are discussed in detail in the RIA 
and its supporting documents and references.
    In determining the overall economic consequences of the final rule, 
it is essential to consider not only the costs and benefits expressed 
in dollar terms but also those benefits and costs that we could not 
quantify. A full listing of the benefit categories that could not be 
quantified or monetized in our analysis is provided in Table 3 of this 
preamble.

IV. Summary of Responses To Major Comments and Changes to the Plywood 
and Composite Wood Products NESHAP

    We proposed the PCWP NESHAP on January 9, 2003 (68 FR 1276), and 
received 57 comment letters on the proposal during the comment period. 
In response to the public comments received on the proposed rule, we 
made several changes in developing today's final rule. Table 4 of this 
preamble provides a list of the major changes that we made to the final 
rule. The major comments and our responses are summarized in the 
following sections. A complete summary of the comments received during 
the comment period and responses thereto can be found in the background 
information document (BID) for the promulgated rule, which is available 
from several sources (see SUPPLEMENTARY INFORMATION section).

      Table 4.--Summary of Major Changes to Subpart DDDD of Part 63
------------------------------------------------------------------------
       Proposed section           Final section     Change from proposal
------------------------------------------------------------------------
Sec.   63.2231................  Sec.   63.2231...  Revised section to
                                                    state that subpart
                                                    DDDD does not apply
                                                    to facilities that
                                                    are part of the low-
                                                    risk subcategory of
                                                    PCWP manufacturing
                                                    facilities.
Sec.   63.2232(b).............  Sec.   63.2232(b)  Description of
                                                    affected source
                                                    revised to be
                                                    consistent with
                                                    revised definition.
Sec.   63.2240................  Sec.   63.2240...  Clarified application
                                                    of compliance
                                                    options to a single
                                                    process unit.
Sec.   63.2240(a).............  Sec.   63.2240(a)  Added wet control
                                                    device to the list
                                                    of devices that may
                                                    not be used to meet
                                                    the PBCO.
Sec.   63.2240(b).............  Sec.   63.2240(b)  Changed press
                                                    enclosure reference
                                                    from ``PTE'' to
                                                    ``wood products
                                                    enclosure.''

[[Page 45959]]

 
Sec.   63.2240(c)(1)..........  Sec.               Revised definition of
                                 63.2240(c)(1).     AMR and OCEPi in
                                                    emissions averaging
                                                    calculations to
                                                    clarify that sources
                                                    can receive partial
                                                    credits from debit-
                                                    generating process
                                                    units that are
                                                    undercontrolled;
                                                    revised definition
                                                    of CDi to address
                                                    test method for
                                                    biological treatment
                                                    units that do not
                                                    meet the definition
                                                    of biofilter.
Sec.   63.2240(c)(2)(iii).....  Sec.               Revised restriction
                                 63.2240(c)(2)(ii   on emissions average
                                 i).                related to process
                                                    units that are
                                                    already controlled.
                                Sec.   63.2241(c)  Added new section
                                                    that exempts dry
                                                    rotary dryers,
                                                    hardwood veneer
                                                    dryers, and veneer
                                                    redryers from work
                                                    practice
                                                    requirements if they
                                                    comply with more
                                                    stringent standards
                                                    in Sec.   63.2240.
Sec.   63.2250(a).............  Sec.   63.2250(a)  Revised section to
                                                    clarify that SSM
                                                    refers to both
                                                    process unit and
                                                    control device SSM.
Sec.   63.2250(d).............  Sec.   63.2250(a)  Moved and revised
                                                    section to
                                                    consolidate
                                                    explanation of SSM
                                                    provisions.
                                Sec.   63.2250(d)  Added specific
                                                    example of a
                                                    shutdown for direct-
                                                    fired burners and a
                                                    specific example of
                                                    a startup for direct-
                                                    fired softwood
                                                    veneer dryers.
Sec.   63.2250(e).............  .................  Removed requirement
                                                    to record control
                                                    device maintenance
                                                    schedule.
Sec.   63.2250(f).............  .................  Removed requirement
                                                    to maintain and
                                                    operate catalyst
                                                    according to
                                                    manufacturer's
                                                    specifications.
Sec.   63.2251(a).............  Sec.   63.2251(a)  Added partial list of
                                                    events eligible for
                                                    a routine control
                                                    device exemption;
                                                    clarified duty to
                                                    minimize emissions.
Sec.   63.2251(b)(1)..........  Sec.               Specified type of
                                 63.2251(b)(1).     strand dryer
                                                    controlled by a
                                                    control device
                                                    eligible for a
                                                    routine control
                                                    device maintenance
                                                    exemption of 3
                                                    percent of annual
                                                    uptime.
Sec.   63.2251(b)(2)..........  Sec.               Added conveyor strand
                                 63.2251(b)(2).     dryer to list of
                                                    process units
                                                    controlled by a
                                                    control device
                                                    eligible for a
                                                    routine control
                                                    device maintenance
                                                    exemption of 0.5
                                                    percent of annual
                                                    uptime.
Sec.   63.2251(e).............  Sec.   63.2251(e)  Removed requirement
                                                    to schedule control
                                                    device maintenance
                                                    at the beginning of
                                                    each semi-annual
                                                    period.
Sec.   63.2260(a).............  Sec.   63.2260(a)  Expanded exemption
                                                    from testing and
                                                    monitoring
                                                    requirements to all
                                                    combustion units
                                                    that introduce
                                                    process unit exhaust
                                                    into the flame zone.
Sec.   63.2262(d).............  Sec.               Added sampling
                                 63.2262(d)(1).     location
                                Sec.                requirements for
                                 63.2262(d)(2).     control devices in
                                                    sequence, process
                                                    units with no
                                                    control device, and
                                                    process units with a
                                                    wet control device.
Sec.   63.2262(g).............  Sec.               Reworded and
                                 63.2262(g)(1).     renumbered section
                                                    to allow for one
                                                    case in which non-
                                                    detect data is not
                                                    considered to be one-
                                                    half the method
                                                    detection limit.
                                Sec.               Added exception to
                                 63.2262(g)(2).     requirement to treat
                                                    non-detect data as
                                                    one-half the
                                                    detection limit.
Sec.   63.2262(k)(1)..........  Sec.               Clarified
                                 63.2262(k)(1).     requirements for
                                                    establishing the
                                                    minimum firebox
                                                    temperature for
                                                    thermal oxidizers.
Sec.   63.2262(k)(2)..........  .................  Removed sections on
Sec.   63.2262(k)(3)..........                      establishing
                                                    operating parameter
                                                    limits for static
                                                    pressure and stack
                                                    gas flow for thermal
                                                    oxidizers.
Sec.   63.2262(k)(4)..........  Sec.               Removed references to
                                 63.2262(k)(2).     static pressure and
                                                    gas flow rate
                                                    operating
                                                    parameters.
Sec.   63.2262(k)(5)..........  Sec.               Revised eligibility
                                 63.2262(k)(3).     criteria for
                                                    exemptions from
                                                    performance testing
                                                    and operating
                                                    requirements for
                                                    thermal oxidizers.
Sec.   63.2262(l)(1)..........  Sec.               Clarified
                                 63.2262(l)(1).     requirements for
                                                    establishing the
                                                    minimum catalytic
                                                    oxidizer
                                                    temperature.
Sec.   63.2262(l)(2)..........  .................  Removed sections on
Sec.   63.2262(l)(3)..........                      establishing
                                                    operating parameter
                                                    limits for static
                                                    pressure and stack
                                                    gas flow for
                                                    catalytic oxidizers.
Sec.   63.2262(l)(4)..........  Sec.               Removed references to
                                 63.2262(l)(2).     static pressure and
                                                    gas flow rate
                                                    operating
                                                    parameters.
Sec.   63.2262(m)(1)..........  Sec.               Revised requirements
Sec.   63.2262(m)(2)..........   63.2262(m)(1).     for establishing
                                Sec.                biofilter operating
                                 63.2262(m)(2).     limits (temperature
                                                    range).
Sec.   63.2262(n)(1)..........  Sec.               Revised monitoring
                                 63.2262(n)(1).     requirements for
                                                    process units that
                                                    meet compliance
                                                    options without the
                                                    use of an add-on
                                                    control device.
Sec.   63.2267................  Sec.   63.2267...  Added initial
                                                    compliance criteria
                                                    for a wood products
                                                    enclosure.
                                Sec.   63.2268...  Added criteria for
                                                    demonstration of
                                                    initial compliance
                                                    for a wet control
                                                    device.
Sec.   63.2268(a)(1)..........  Sec.               Revised continuous
                                 63.2269(a)(1).     parameter monitoring
                                                    system requirements.
Sec.   63.2268(a)(3)..........  Sec.   63.2270(d)  Revised and moved
Sec.   63.2268(a)(4)..........  Sec.   63.2270(e)   sections regarding
                                                    determination of
                                                    block averages and
                                                    valid data to
                                                    section on
                                                    continuous
                                                    compliance
                                                    requirements.
Sec.   63.2268(b)(2)..........  Sec.               Clarified temperature
Sec.   63.2268(b)(3)..........   63.2269(b)(2).     measurement
                                Sec.                requirements.
                                 63.2268(b)(3).
Sec.   63.2268(c).............  .................  Removed sections
Sec.   63.2268(d).............  .................   regarding pH,
Sec.   63.2268(e).............  .................   pressure, and flow
                                                    monitoring.

[[Page 45960]]

 
Sec.   63.2268(f)(1)..........  Sec.               Revised requirements
Sec.   63.2268(f)(2)..........   63.2269(c)(1).     for wood moisture
                                Sec.                monitoring.
                                 63.2269(c)(2).
                                Sec.               Added equation for
                                 63.2269(c)(5).     converting moisture
                                                    measurements from
                                                    wet basis to dry
                                                    basis.
Sec.   63.2270(c).............  Sec.   63.2270(c)  Added language to
                                                    specify that data
                                                    recorded during
                                                    periods of SSM may
                                                    not be used in data
                                                    averages and
                                                    calculations used to
                                                    report emission or
                                                    operating levels.
                                Sec.   63.2270(f)  Added requirement
                                                    that 75 percent of
                                                    readings recorded
                                                    and included in
                                                    block averages must
                                                    be based on valid
                                                    data.
Sec.   63.2280(f)(6)..........  Sec.               Revised EAP
                                 63.2280(f)(6).     submission
                                                    requirements to
                                                    include information
                                                    on debit-generating
                                                    process units.
                                Sec.   63.2282(e)  Added requirement to
                                                    keep records of
                                                    annual catalyst
                                                    activity checks and
                                                    subsequent
                                                    corrective actions
                                                    for catalytic
                                                    oxidizers.
Sec.   63.2291................  Sec.   63.2291...  Revised section to
                                                    state that EPA
                                                    retains authority to
                                                    review eligibility
                                                    demonstrations for
                                                    the low-risk
                                                    subcategory.
                                Sec.   63.2292...  Added definitions of
                                                    ``agricultural
                                                    fiber,''
                                                    ``combustion unit,''
                                                    ``conveyor strand
                                                    dryer,'' ``conveyor
                                                    strand dryer zone,''
                                                    ``flame zone,''
                                                    ``group 1
                                                    miscellaneous
                                                    coating
                                                    operations,'' ``non-
                                                    HAP coating,'' ``one-
                                                    hour period,''
                                                    ``partial wood
                                                    products
                                                    enclosure,''
                                                    ``primary tube
                                                    dryer,'' ``rotary
                                                    strand dryer,''
                                                    ``secondary tube
                                                    dryer,'' ``wet
                                                    control device,''
                                                    and ``wood products
                                                    enclosure.''
Sec.   63.2292................  .................  Removed definitions
                                                    of ``permanent total
                                                    enclosure,'' ``plant
                                                    site,'' and ``strand
                                                    dryer.''
Sec.   63.2292................  Sec.   63.2292...  Revised definitions
                                                    of ``affected
                                                    source,''
                                                    ``biofilter,''
                                                    ``deviation,''
                                                    ``fiber,''
                                                    ``fiberboard,''
                                                    ``hardboard,''
                                                    ``medium density
                                                    fiberboard,''
                                                    ``miscellaneous
                                                    coating
                                                    operations,''
                                                    ``particle,''
                                                    ``particleboard,''
                                                    ``plywood and
                                                    composite wood
                                                    products (PCWP)
                                                    manufacturing
                                                    facility,''
                                                    ``softwood veneer
                                                    dryer,'' and
                                                    ``thermal
                                                    oxidizer.''
Table 1A......................  Table 1A.........  Changed ``tube
                                                    dryers'' to
                                                    ``primary tube
                                                    dryers'' and added
                                                    ``secondary tube
                                                    dryers''; added PBCO
                                                    limit for secondary
                                                    tube dryers; revised
                                                    PBCO limit for
                                                    reconstituted wood
                                                    product board
                                                    coolers; changed
                                                    ``strand dryers'' to
                                                    ``rotary strand
                                                    dryers.''
Table 1B......................  Table 1B.........  Added ``rotary strand
                                                    dryers,'' ``conveyor
                                                    strand dryer zone
                                                    one (at existing
                                                    affected sources),''
                                                    and ``conveyor
                                                    strand dryer zones
                                                    one and two (at new
                                                    affected sources)''
                                                    to the list of
                                                    process units.
Table 2, Line 1...............  Table 2, Line 1..  Reduced thermal
                                                    oxidizer operating
                                                    requirements to
                                                    maintaining the
                                                    average firebox
                                                    temperature above
                                                    the minimum
                                                    temperature.
Table 2, Line 2...............  Table 2, Line 2..  Reduced catalytic
                                                    oxidizer operating
                                                    requirements to
                                                    maintaining the
                                                    temperature above a
                                                    minimum temperature
                                                    and checking the
                                                    activity level of a
                                                    representative
                                                    sample of the
                                                    catalyst every 12
                                                    months.
Table 2, Line 3...............  Table 2, Line 3..  Reduced biofilter
                                                    operating
                                                    requirements to
                                                    maintaining the
                                                    biofilter bed
                                                    temperature within a
                                                    range.
Table 2, Line 5...............  Table 2, Line 5..  Revised operating
                                                    requirements for
                                                    process units
                                                    without control
                                                    devices.
                                Table 3, Line 5..  Added work practice
                                                    requirements for
                                                    group 1
                                                    miscellaneous
                                                    coating operations.
Table 4, Line 9...............  Table 4, Line 9..  Revised the
                                                    performance test
                                                    criteria for
                                                    reconstituted wood
                                                    product presses and
                                                    reconstituted wood
                                                    product board
                                                    coolers.
Table 4, Line 11..............  Table 4, Line 11.  Revised text to
                                                    clarify that
                                                    performance test
                                                    requirements apply
                                                    to all process units
                                                    in an emissions
                                                    average plan.
Table 5, Line 7...............  Table 5, Line 7..  Removed minimum heat
                                                    input capacity
                                                    criterion for
                                                    combustion units.
                                Table 5, Line 8..  Added criteria for
                                                    performance testing
                                                    and initial
                                                    compliance
                                                    demonstrations for
                                                    wet control devices.
                                Table 6, Line 5..  Added initial
                                                    compliance
                                                    demonstration for
                                                    Group 1
                                                    miscellaneous
                                                    coating operations.
Table 7, Line 1...............  Table 7, Line 1..  Revised ``at or above
                                                    the maximum, at or
                                                    below the minimum''
                                                    to read ``at or
                                                    above the minimum,
                                                    at or below the
                                                    maximum.''
                                Table 7, Line 3..  Added continuous
                                                    compliance
                                                    requirements
                                                    (periodic testing)
                                                    for biofilters.
                                Table 7, Line 4..  Added continuous
                                                    compliance
                                                    requirements (annual
                                                    catalyst activity
                                                    check) for catalytic
                                                    oxidizers.
                                Table 7, Line 5..  Added continuous
                                                    compliance
                                                    requirements for
                                                    process units
                                                    achieving compliance
                                                    without an add-on
                                                    control device.
Table 8, Line 1...............  Table 8, Line 1..  Specified block
                                                    averages of 24 hours
                                                    for moisture and
                                                    temperature
                                                    measurements for dry
                                                    rotary dryers.
Table 8, Line 4...............  Table 8, Line 4..  Specified block
                                                    average of 24 hours
                                                    for moisture
                                                    measurements for
                                                    veneer dryers.
                                Table 8, Line 5..  Added continuous
                                                    compliance
                                                    requirements for
                                                    Group 1
                                                    miscellaneous
                                                    coating operations.
Table 10, Sec.   63.8(g)......  Table 10, Sec.     Added ``rounding of
                                 63.8(g).           data'' to
                                                    description of the
                                                    General Provisions
                                                    section.

[[Page 45961]]

 
Appendix A to Subpart DDDD....  Appendix A to      Made various
                                 Subpart DDDD.      revisions throughout
                                                    to reflect the
                                                    removal of a
                                                    permanent total
                                                    enclosure (PTE) as a
                                                    requirement for
                                                    reconstituted wood
                                                    products presses and
                                                    board coolers.
                                Appendix B to      Added appendix B to
                                 Subpart DDDD.      specify procedure
                                                    for demonstrating
                                                    that an affected
                                                    source is part of
                                                    the low-risk
                                                    subcategory.
------------------------------------------------------------------------

A. Applicability

1. Definition of Affected Source
    Comment: Several commenters requested that we clarify that the PCWP 
affected source includes refining and resin preparation activities such 
as mixing, formulating, blending, and chemical storage, and suggested 
that boilers be excluded. The commenters wanted to ensure that onsite 
resin preparation activities are specifically mentioned in and 
regulated by the final PCWP rule to avoid duplicate regulation of those 
activities under the Miscellaneous Organic Chemical Manufacturing 
NESHAP (subpart FFFF) or the Miscellaneous Coating Manufacturing NESHAP 
(subpart HHHHH). Commenters also recommended changing the proposed 
definition of affected source by revising the definition of ``plant 
site,'' which was used in the affected source definition at proposal. 
The commenters asked that we make the definition of ``plant site'' 
consistent with the definition of ``major source'' as defined for title 
V permitting in 40 CFR 70.2. According to the commenters, the proposed 
definition of ``plant site'' expanded the definition of a source beyond 
that used for title V permitting or MACT applicability in general.
    Response: We agree with the commenters that changes should be made 
to the definition of affected source, and the definition was adjusted 
in the final rule. We added resin preparation activities to the 
definition of ``affected source'' to clarify that these activities are 
part of the PCWP source category and are not subject to subpart FFFF to 
40 CFR part 63 or subpart HHHHH to 40 CFR part 63. Resin preparation 
includes any mixing, blending, or diluting of resins used in the 
manufacture of PCWP products which occurs at the PCWP manufacturing 
facility. We feel this change is appropriate because the MACT analysis 
for resin preparation activities was conducted under the PCWP final 
rulemaking. (As explained in the proposal BID and supporting 
documentation, we determined that MACT for new and existing blenders 
and resin storage/mixing tanks is no emissions reductions.) Subpart 
FFFF to 40 CFR part 63 and subpart HHHHH to 40 CFR part 63 exclude 
activities included as part of the affected source for other source 
categories. Thus, onsite resin preparation activities at a PCWP 
manufacturing facility are not subject to subpart FFFF to 40 CFR part 
63 or subpart HHHHH to 40 CFR part 63.
    We added refiners to the definition of affected source to clarify 
that these sources are part of the affected source and were part of the 
MACT analysis for the PCWP source category. (For new and existing 
pressurized refiners, we determined that MACT is based on the use of 
incineration-based control or a biofilter, and for new and existing 
atmospheric refiners, we determined that MACT is no emissions 
reductions.)
    We removed all references to ``plant site'' from the final rule and 
replaced references to ``plant site'' with the term ``facility'' to 
eliminate confusion regarding which emission sources constitute the 
affected source and which emission sources would be considered when 
making a major source determination. The term ``plant site'' was used 
only in the proposed definitions of ``affected source'' and ``plywood 
and composite wood products manufacturing facility.'' Inclusion of the 
term ``plant site'' in the proposed definition of affected source 
unintentionally broadened the definition such that emission sources not 
related to PCWP manufacturing could be construed as being part of the 
affected source. For example, under the proposed definitions of 
``affected source'' and ``plant site,'' if a company operated both a 
PCWP manufacturing facility and a wood building products surface 
coating facility at the same site, both operations might be considered 
to be part of the PCWP affected source because the ``plant site'' would 
encompass both operations, even though these two operations are 
regulated under separate NESHAP. We removed the term ``plant site'' 
from the final rule to clarify that the requirements in the final rule 
would only apply to the affected source, which is the PCWP 
manufacturing facility. However, we note that any major source 
determination would be based on total emissions from both operations 
since the two operations are colocated and under common control. (See 
definition of major source in the General Provisions (40 CFR part 63, 
subpart A).)
    We did not incorporate the commenters' suggestion to specifically 
exclude boilers from the definition of ``affected source'' because it 
is possible for a boiler to be subject to both the PCWP NESHAP and the 
Industrial/Commercial/Institutional Boilers and Process Heaters NESHAP 
(e.g., if a portion of the boiler exhaust is used to direct fire dryers 
while the remaining portion of the boiler exhaust is vented to the 
atmosphere). However, in most cases, combustion units would only be 
subject to one MACT. The overlap between the PCWP NESHAP and the 
Industrial/Commercial/Institutional Boilers and Process Heaters NESHAP 
is also discussed in this preamble.
2. Process Definitions
    Comment: Commenters recommended that a number of definitions 
included in the proposed rule be revised to better distinguish between 
particleboard, MDF and hardboard and/or to be consistent with 
definitions developed by the American National Standards Institute 
(ANSI).
    Response: We made changes to several of the proposed process-
related definitions including the definitions of particle, fiber, 
hardboard, MDF, and particleboard. These minor changes incorporate some 
of the wording in similar definitions used by ANSI but do not affect 
the scope or applicability of the final rule. We also added a 
definition of agricultural fiber recommended by commenters because the 
term ``agricultural fiber'' appears in the definition of plywood and 
composite wood products facility.
    Comment: Several commenters requested that the proposed definition 
of tube dryer be changed so that stages in multistage tube dryers would 
be considered as separate tube dryers. With this change, different 
control options could be applied to different dryer stages.
    Response: Under the proposed definition of tube dryer, a multistage 
tube dryer with more than one control

[[Page 45962]]

device and emissions point would be considered one process unit. In 
developing the proposed rule, we noted that the function of tube dryers 
is the same regardless of single-or multistage configuration and that 
distinguishing between dryer configurations would not change the 
results of the MACT floor analysis, despite the fact that the majority 
of the HAP emissions exhaust from the primary stage. Therefore, we made 
no distinction between single-stage and multistage tube dryers at 
proposal. However, we agree with the commenters that defining the 
stages of multistage tube dryers separately would allow facilities the 
flexibility of choosing different compliance options for each stage of 
the tube dryer, and we have included separate definitions of primary 
tube dryer and secondary tube dryer in the final rule. The MACT floor 
for both primary tube dryers and secondary tube dryers is the same 
(e.g., 90 percent reduction in emissions), but facilities may choose 
different control options for the primary and secondary tube dryers. 
For example, a facility with a multistage tube dryer could use an add-
on control device to reduce emissions from the primary tube dryer only 
and then use emissions averaging to offset the uncontrolled emissions 
from the secondary tube dryer.
3. Lumber Kilns
    Comment: We received comments from representatives of sawmills and 
wood treating facilities disagreeing with the inclusion of lumber kilns 
in the PCWP source category. The commenters stated that owners and 
operators of kilns that are not located at a PCWP facility may be 
subject to other requirements of the rule, as proposed, that do not 
truly apply to them, including costly monitoring, recordkeeping, and 
reporting. One commenter was concerned that the owners and operators of 
non-colocated lumber kilns could find themselves in violation of the 
May 15, 2002, case-by-case ``MACT Hammer'' deadline even though they 
did not anticipate being included in the rule, as proposed, and thus 
did not apply for the case-by-case consideration.
    Response: At proposal, we broadened the PCWP source category to 
include non-colocated lumber kilns (i.e., lumber kilns located at 
stand-alone kiln-dried lumber manufacturing facilities or at any other 
type of facility). In the preamble to the proposed rule, we noted that 
if non-colocated lumber kilns were not included in the PCWP NESHAP, 
then kiln-dried lumber manufacturing could be listed as a major source 
category under section 112(c) of the CAA in the future, requiring a 
separate CAA section 112(d) rulemaking and potentially becoming 
separately subject to the provisions of section 112(g) of the CAA as 
well. We felt it was reasonable to include non-colocated lumber kilns 
in the PCWP source category because the design and operation of lumber 
kilns are essentially the same regardless of whether the kilns are 
located at a sawmill or are colocated with PCWP or other types of 
manufacturing operations. At proposal, we noted that there are no 
currently applicable controls at any lumber kilns and that it would be 
both more efficient and expeditious to include all lumber kilns in the 
MACT analysis for the final PCWP rule than to separately address them 
in a rulemaking that likely would not result in meaningful emissions 
reductions from lumber kilns. In addition, we noted that including all 
lumber kilns in the final PCWP MACT results in placing them on a faster 
schedule for purposes of future residual risk analysis under CAA 
section 112(f).
    In an attempt to better understand the concerns of the commenters, 
we met with wood products industry representatives who requested that 
lumber kilns be included in the PCWP source category and with the 
commenters who disagreed that non-colocated lumber kilns should be 
included in the PCWP source category. After consideration of concerns 
expressed by all of the commenters on this issue, we maintain that it 
is more efficient for EPA, State regulators, and lumber kiln operators 
for EPA to include all lumber kilns in the final PCWP NESHAP. Because 
the MACT floor determination for lumber kilns is no emission reduction 
(as explained in the proposal preamble), there will not be a 
significant monitoring, recordkeeping, and reporting burden for 
facilities with only non-colocated lumber kilns. Only those facilities 
that are major sources of HAP emissions are subject to the final PCWP 
NESHAP. Facilities with non-colocated lumber kilns that are classified 
as major sources of HAP must submit an initial notification form 
required by the final PCWP NESHAP and the Part 1 ``MACT Hammer'' 
application required by section 112(j) of the CAA. We note that both of 
these forms simply ask the facilities to identify themselves to EPA. We 
acknowledge that operators of non-colocated lumber kilns were not aware 
that they were included in the PCWP source category until the proposed 
PCWP NESHAP was printed in the Federal Register on January 9, 2003, and 
therefore, would not have known to submit a Part 1 application by May 
15, 2002.
4. Regulated HAP
    Comment: One commenter objected to the fact that the proposed rule 
only set standards for six HAP. The commenter asserted that, according 
to the CAA and National Lime Ass'n v. EPA, 233 F.3d 625, 633-634 (D.C. 
Cir. 2000), we are required to set standards for every HAP listed in 
CAA section 112(b)(1) emitted by PCWP operations, not just the ones 
that are the easiest to measure. Other commenters disagreed and noted 
that a requirement that EPA impose an emission standard for every 
listed HAP, without regard to whether or not there are applicable 
methods for reducing HAP emissions or whether the MACT floor sources 
actually use such method, contradicts the plain language of the 
statute. These commenters contended that the statute specifically 
frames the inquiry in terms of degrees of reduction.
    Response: Today's final PCWP rule contains numerical emission 
limits in terms of methanol, formaldehyde, THC, or total HAP (which is 
defined in the final rule as the sum of six HAP including acrolein, 
acetaldehyde, formaldehyde, methanol, phenol, and propionaldehyde). The 
nationwide PCWP emissions of total HAP are 18,190 tons/yr, which is 96 
percent of the nationwide emissions of all HAP (19,000 tons/yr) emitted 
by PCWP facilities. The six HAP that comprise total HAP are found in 
emissions from all PCWP product sectors that contain major sources and 
in emissions from most process units. At proposal, when we stated that 
other HAP are emitted ``in low quantities that may be difficult to 
measure,'' we were referring to HAP that are often emitted at levels 
below test method detection limits (68 FR 1276, January 9, 2003). Our 
data clearly show that these other HAP are difficult or impossible to 
measure because they are either emitted in very low quantities or are 
not present. Such low quantities are not detectable by the applicable 
emission testing procedures (which are sensitive enough to detect HAP 
at concentrations below 1 part per million (ppm)). Many of these other 
HAP were detected in less than 15 percent of test runs, or for only one 
type of process unit.
    Based on our emissions data, we determined that methanol, 
formaldehyde, THC, or total HAP are appropriate surrogates for 
measuring all organic HAP measurably-emitted by the PCWP source 
category. The PBCO and emissions averaging compliance options in 
today's final PCWP rule are based on total HAP. Review of the emission

[[Page 45963]]

factors used to develop the emissions estimates for the PCWP source 
category indicates that uncontrolled emissions of HAP (other than the 
six HAP) are always lower than emissions of the six HAP for every 
process unit with MACT control requirements. Thus, process units 
meeting the PBCO based on total HAP also would have low emissions of 
other organic HAP. The emissions averaging provisions and add-on 
control device compliance options involve use of add-on APCD. The 
available data show that a reduction in one predominant HAP (or THC) 
correlates with a reduction in other HAP if the other HAP is present in 
detectable quantities and at sufficient concentration. The data also 
show that the mechanisms in RTO, RCO, and biofilters that reduce 
emissions of formaldehyde and methanol reduce emissions of the 
remaining HAP. In addition, an analysis of the physical properties of 
the organic HAP emitted from PCWP processes indicates that nearly all 
of the HAP would be combusted at normal thermal oxidizer operating 
temperatures. Today's standards are based on the use of add-on control 
devices because the available emissions data do not reveal any process 
variables that could be manipulated (without altering the product) to 
achieve a quantifiable reduction in emissions. Furthermore, nothing in 
the data suggests that process variables could be manipulated in a way 
that would alter the relationship between formaldehyde and methanol 
reduction and reduction of other HAP. We determined that it is 
appropriate for the final PCWP rule to contain compliance options in 
terms of total HAP, THC, formaldehyde, or methanol because the same 
measures used to reduce emissions of these pollutants also reduce 
emissions of other organic HAP.

B. Overlap With Other Rules

1. Overlap With Industrial/Commercial/Institutional Boilers and Process 
Heaters NESHAP
    Comment: Commenters expressed support for our proposal to regulate 
emissions from combustion units used to direct fire dryers and to 
exclude these emissions from the requirements of the Industrial/
Commercial/Institutional Boilers and Process Heaters NESHAP. However, 
the commenters expressed concern about potential NESHAP applicability 
questions that could arise during short periods when the exhaust gases 
from these combustion units are not exhausting through the dryers and 
would bypass any controls applied to these dryers. The commenters noted 
that in some of the combustion units associated with direct-fired 
dryers, a small percentage of combustion gas is routed to indirect heat 
exchange and then is normally and predominantly routed to direct-fired 
gas flow. According to the commenters, in these hybrid units, typically 
only a small fraction of combustion gas (e.g., less than 10 percent of 
total capacity) is routed to indirect heat exchange for hot oil/steam 
generation. This fraction of the combustion unit exhaust then generally 
exhausts through the direct-fired dryers and the emissions are treated 
by the add-on control device at the dryers' outlet. However, under 
certain circumstances (e.g., during startups, shutdowns, emergencies, 
or periods when dryers are down for maintenance but steam/thermal oil 
is still needed for plant and/or press heat), some systems may exhaust 
directly to the atmosphere without passing through the direct-fired 
dryers and the associated control systems. The commenters recommended 
that this small subset of combustion units be assigned a primary 
purpose (based on the predominant allocation of British thermal units 
per hour (Btu/hr) capacity and/or predominant mode of operation) and 
regulated accordingly. In the above example, the commenters assumed 
that the primary purpose is as a direct-fired dryer, such that the 
equipment would be subject to the final PCWP MACT and not to the 
Industrial/Commercial/Institutional Boilers and Process Heaters NESHAP.
    Response: In considering the commenters' request, we reviewed 
available information on direct-fired dryers and the associated 
combustion units at PCWP facilities. The available information 
indicates that there are many configurations of combustion units, 
dryers, and thermal oil heaters in the PCWP industry. While some 
systems have the hybrid configurations described by the commenters 
whereby a portion of the combustion gas is routed to indirect heat 
exchange, other systems retain all of the combustion gas within the 
direct-fired system. We do not have sufficient information (and no such 
information was provided by the commenters) to fully evaluate the need 
for a primary purpose designation for PCWP combustion units, to 
establish the percentage-of-operating-time or British thermal unit 
(Btu) limits for such a primary purpose designation, or to determine 
MACT for combustion units that would meet the primary purpose 
designation. For example, we do not know how many combustion units are 
configured to incorporate both indirect and direct heat exchange, and 
for these units we do not know the amount of time or the percentage of 
Btu allocation that is devoted to indirect heat exchange or the 
controls used to reduce emissions during indirect heat exchange. We 
expect that all of these factors vary substantially from facility to 
facility for those facilities that have these hybrid combustion units. 
We also lack information on the emissions reduction techniques (e.g., 
control devices) applied to combustion units associated with direct-
fired PCWP dryers that may bypass the dryers for some unknown 
percentage of time. Therefore, we feel it would be inappropriate for us 
to establish a primary purpose designation which could inadvertently 
allow facilities to configure their systems to direct a portion of 
their uncontrolled emissions to the atmosphere without these emissions' 
being subject to the Industrial/Commercial/Institutional Boilers and 
Process Heaters NESHAP. Also, we wish to clarify that the final PCWP 
rule regulates only that portion of emissions from a combustion unit 
that are routed through the direct-fired dryers. Any emissions from a 
combustion unit that are not routinely through the direct-fired dryers 
would be subject to the Industrial/Commercial/Institutional Boilers and 
Process Heaters NESHAP. Therefore, if the emissions from a combustion 
unit are split such that only a portion of the emissions are routed 
through a direct-fired dryer, then the combustion unit would be subject 
to both rules.
    For those occasions when a facility must shut down its direct-fired 
dryers but still wants to operate the combustion unit to heat oil for 
the press, the facility could propose in its startup, shutdown, and 
malfunction (SSM) plan to route exhaust through the thermal oil heater 
(and then to the atmosphere) during these periods. The permitting 
authority would then decide on a facility-specific basis if heating of 
the thermal oil heater (and the associated uncontrolled emissions) 
should be allowed during dryer SSM considering the amount of time that 
this condition occurs, the fraction of combustion unit Btu used to heat 
the thermal oil heater, and the type of control used to reduce 
combustion unit emissions.
2. Overlap With Wood Building Products (WBP) NESHAP
    Comment: Commenters on the proposed Wood Building Products (Surface 
Coating) rule (subpart QQQQ to 40 CFR part 63) asserted that neither 
asphalt-coated fiberboard nor ceiling tiles are coated with HAP-
containing

[[Page 45964]]

materials and that regulating such products would be burdensome. These 
commenters requested that we include asphalt coating of fiberboard and 
ceiling tiles in today's final PCWP rule by including these coating 
operations under the definition of miscellaneous coating operations 
(for which the proposed MACT was no emissions reductions), so that 
these operations would be subject to the final PCWP rule and not the 
WBP rule, as proposed.
    Response: In the proposed rule, we addressed overlap between the 
WBP and PCWP NESHAP by including specific surface coating activities 
(which occur onsite at a PCWP manufacturing facility) in the definition 
of ``miscellaneous coating operations.'' Inclusion of these activities 
in the definition of miscellaneous coating operations means that these 
activities are subject to the final PCWP rule and not to the WBP rule, 
as proposed. We made changes to the definition of miscellaneous coating 
operations in today's final rule in response to the public comments we 
received on the proposed WBP rule relating to asphalt-coated fiberboard 
and ceiling tiles.
    We evaluated the types of coatings and processes used to make 
asphalt-coated fiberboard and found that only a few facilities in the 
United States make these products, with varying manufacturing and 
coating processes. An asphalt emulsion can be added during the 
fiberboard forming process, or asphalt can be applied to the fiberboard 
substrate. Information we collected on asphalt coatings suggests that 
they contain no HAP. Depending on the company and the process, the 
coating can be applied before or after the final dryer with the product 
allowed to air dry. Ceiling tiles are usually coated using non-HAP 
slurries of titanium dioxide and various clays, and no organic solvents 
are used. Most of the coatings associated with these types of products 
are applied during the substrate forming process (i.e., to the wet mat 
being formed) or prior to the final substrate drying operation, 
fiberboard coating operations (including those used in the manufacture 
of asphalt-coated fiberboard and ceiling tiles). Because no HAP are 
contained in the above-mentioned coatings, the coatings are applied as 
part of the manufacturing process, and MACT for these coating processes 
is no emissions reductions, we changed the definition of miscellaneous 
coating operations to include ``application of asphalt, clay slurry, or 
titanium dioxide coatings to fiberboard at the same site of fiberboard 
manufacture.'' These products are not subject to the final WBP surface 
coating rule.

C. Amendments to the Effluent Guidelines for Timber Products Processing

    Comment: Several commenters requested that we address potential 
conflicts between the PCWP rule as proposed and the effluent guidelines 
for the Timber Products Processing Point Source Category. These 
commenters noted that the effluent guidelines state that ``there shall 
be no discharge of process wastewater pollutants into navigable 
waters.'' However, according to the commenters, at the time that 
statement was written, air pollution controls were not common, and EPA 
was not aware of the large volumes of water that can be produced by 
APCD. The commenters recommended that we address this issue by revising 
the effluent guidelines at 40 CFR part 429. Specifically, these 
commenters asked us to amend the definition of process wastewaters at 
40 CFR part 429.11(c) so that the discharge prohibition in 40 CFR part 
429 would not apply to wastewaters associated with APCD operation and 
maintenance when installed to comply with the final PCWP MACT rule. 
These commenters asserted that effluent limitations for these 
wastewaters should be developed by permit writers on a case-by-case 
basis based upon best professional judgment. These commenters noted 
that the language we included in the preamble to the proposed rule 
would generally accomplish this purpose with some minor changes (see 68 
FR 1276, January 9, 2003). The commenters also provided rationale and 
data to support their recommendation. The commenters contended that we: 
(1) Underestimated the volume of wastewater that would be generated by 
the application of MACT and as a result, underestimated the associated 
costs of disposing of this wastewater; (2) failed to address the 
achievability/feasibility of MACT if the discharge of air pollution 
control wastewaters is prohibited; and (3) did not consider wastewater 
from air pollution control devices when the Timber Products zero 
discharge effluent guidelines were originally developed. The commenters 
submitted several case studies to demonstrate the variability in the 
volume of wastewater generated at various PCWP facilities and to show 
how each facility currently recycles, reuses, and disposes of 
wastewater generated from the operation and maintenance of RTO, WESP 
and biofilters. The commenters also argued that the available data do 
not support a conclusion that wastewaters generated from MACT control 
devices can, with Best Available Technology (BAT), be managed in a way 
that does not involve a discharge.
    Response: At the time we proposed the PCWP rule, we indicated that 
we would consider amending the definition of process wastewater in 40 
CFR part 429 to exclude those wastewaters generated by APCD operation 
and maintenance when installed to comply with the proposed PCWP NESHAP. 
We indicated in the preamble to the proposal that we would amend the 
definition of process wastewaters if information and data were 
submitted to support the industry's assertions that PCWP facilities in 
certain subcategories would not be able consistently to achieve the 
effluent limitations guidelines and standards applicable to them if 
they were to comply with the proposed PCWP NESHAP. As part of the PCWP 
proposal, we described with specificity how we would revise 40 CFR part 
429 if we were convinced that such revisions were appropriate and 
solicited data and information.
    Based on the data and information submitted by the commenters, we 
have concluded that facilities subject to 40 CFR part 429, subpart B 
(Veneer subcategory), subpart C (Plywood subcategory), subpart D (Dry 
Process Hardboard subcategory), and subpart M (Particleboard 
Manufacturing subcategory) are unable to comply consistently with the 
existing 40 CFR part 429 effluent limitations guidelines and standards, 
which prohibit the discharge of process wastewater pollutants, because 
of the volume of wastewaters generated by APCD that are installed to 
comply with the final PCWP NESHAP and because the technology basis for 
those effluent limitations guidelines and standards is insufficient, in 
light of that wastewater volume and the pollutant content, to achieve 
the prohibition on process wastewater discharges for these NESHAP-
related APCD wastewaters. Therefore, we are excluding from the 
definition of process wastewaters in 40 CFR 29.11(c) the following 
wastewaters associated with APCD used by PCWP facilities covered by 
subparts B, C, D, and M to comply with 40 CFR 63.22: wastewater from 
washout of thermal oxidizers and catalytic oxidizers, wastewater from 
biofilters, and wastewater from WESP used upstream of thermal oxidizers 
or catalytic oxidizers.
    In addition, we agree with comments that we will need considerably 
more data and information to promulgate new effluent limitations 
guidelines and standards for the process wastewaters at issue today. In 
particular, we will need

[[Page 45965]]

information to adequately characterize the quantity and quality of 
wastewater that would be generated as result of compliance with the 
MACT standards. The volume and pollutant content of wastewater 
generated at these facilities are related to production processes, air 
pollution control equipment that generate wastewater, the extent of 
opportunities for internal recycling of wastewater, and the 
availability of other process uses for wastewater. Until we promulgate 
effluent limitations guidelines and standards for pollutants in these 
process wastewaters, Best Practicable Technology (BPT) and BAT effluent 
limitations should be established on a case-by-case basis under 40 CFR 
125.3. Thus, individual facilities seeking a discharge permit will have 
the opportunity, on a case-by-case basis, to characterize and obtain 
discharge allowances for their wastewaters from APCD installed to 
comply with the final PCWP NESHAP. The permit writer would be expected 
to determine, based upon best professional judgment (BPJ), the 
appropriate effluent limitations for these APCD wastewaters. (See 40 
CFR 125.3.) The permit writer can take into account facility-specific 
information on wastewater volumes and pollutants, available wastewater 
control and treatment technologies, costs and effluent reduction 
benefits, receiving water quality, and any applicable State water 
quality standards. At a later date, we expect to consider whether to 
amend the existing effluent limitations guidelines and standards for 
the Timber Processing Industry to cover these process wastewaters. Such 
an effort would involve gathering and analyzing the information and 
data necessary to establish revised categorical effluent limitations 
affecting subparts B, C, D, and M of 40 CFR part 429 for these APCD 
wastewaters generated in complying with the final PCWP NESHAP.
    Today's amendment to the final rule is based on regulatory language 
included in the preamble accompanying the proposed NESHAP for PCWP 
facilities (68 FR 1276, January 9, 2003). The preamble described the 
relationship of the proposed MACT rule to the amendment to 40 CFR part 
429 under consideration. The preamble explained that the entities 
affected by the proposed MACT rule would also be affected by the 
proposed amendment to 40 CFR part 429; presented both the terms and 
substance of the amendment under consideration; and described the 
subjects and issues involved. In addition, we solicited comments on 
whether to amend 40 CFR 429.11(c) and information relevant to that 
decision. While at that time we indicated that we were considering 
employing a direct final rule to promulgate any such amendment, we have 
concluded with support from commenters that that procedure was 
unnecessary and instead are taking final action on the amendment today 
without further process.

D. Existing Source MACT

1. OSB Strand Dryers
    Comment: One commenter requested that further consideration be 
given to the emission standards for low-temperature OSB conveyor strand 
dryers. The commenter stated that because these conveyor strand dryers 
emit less HAP than rotary strand dryers and have been recognized as 
best available control technology (BACT) in Minnesota, they should be 
exempted from control requirements in the final PCWP rule. The 
commenter noted that the 12 conveyor strand dryers used by their 
company have three drying zones, each with its own heating system and 
exhaust vent(s). When drying hardwoods, no VOC control is required; 
however, when drying pine the company controls emissions from zones 1 
and 2. Zone 3 serves as a final conditioning zone and is exhausted to 
the atmosphere without need for VOC control. The proposed PCWP rule 
would have required the sum of the emissions from all three zones to be 
reduced to MACT levels (e.g., 90 percent reduction).
    Response: The MACT analysis we conducted at proposal treated 
conveyor strand dryers as a separate equipment group from rotary strand 
dryers. We noted that rotary strand dryers operate at much higher inlet 
temperatures (e.g., often greater than or equal to 900[deg]F) than 
conveyor strand dryers (e.g., typically less than 400[deg]F) and that 
rotary dryers provide greater agitation of the wood strands than 
conveyor strand dryers. As a result, the emissions from conveyor strand 
dryers are lower than the emissions from rotary strand dryers. The 
emissions test data we have for conveyor strand dryers (only 
formaldehyde and THC data are available) indicate that formaldehyde 
emissions from conveyor strand dryers are 1 to 2 orders of magnitude 
lower than for rotary strand dryers. The THC emissions are also lower 
for conveyor strand dryers than for rotary dryers. Our MACT analysis 
for conveyor strand dryers at proposal concluded that three of the 
eight conveyor strand dryers used in the U.S. operated with process 
incineration. Because there are less than 30 conveyor strand dryers, 
the MACT floor was based on the control level achieved by the third 
best-controlled dryer. Thus, at proposal, we determined that the MACT 
floor control system for new and existing conveyor strand dryers was 
the emissions reductions achievable with incineration-based control. We 
included one definition of ``strand dryers'' in the proposed PCWP rule 
since MACT for both rotary and conveyor strand dryers was represented 
by incineration-based control.
    As pointed out by the commenter, conveyor strand dryers have 
distinct zones, with each zone having its own heating system and 
exhaust. We reviewed our MACT survey data and learned that all of the 
conveyor strand dryers in the U.S. have three zones. Upon further 
scrutiny of the MACT analysis at proposal, we learned that the three 
conveyor strand dryers that formed the basis for the MACT floor at 
proposal were routing the emissions from zone 1 only to an onsite 
combustion unit for incineration. The remaining five conveyor strand 
dryers have no HAP control. Thus, our conclusions regarding the MACT 
floor for conveyor strand dryers at proposal were overstated. The third 
best-controlled conveyor strand dryer has incineration-based control 
only on zone 1 as opposed to controls on all zones. Therefore, we 
revised our analysis to reflect that the MACT floor for existing 
conveyor strand dryers is the emissions reduction achievable with 
incineration-based control on zone 1. To implement this change, we 
added definitions for ``conveyor strand dryer'' and ``conveyor strand 
dryer zone'' to the final rule.
    The commenter mentioned operating 12 conveyor strand dryers. Six of 
these conveyor strand dryers are located at new plants that were not 
included in our pre-proposal MACT floor analysis. These six conveyor 
strand dryers route emissions from zones 1 and 2 to a closed-loop 
incineration system for emissions control. Given that newer facilities 
are incinerating conveyor strand dryer exhaust from zones 1 and 2, we 
determined that the MACT floor for conveyor strand dryers at new 
sources is the emissions reductions achievable with incineration-based 
control for exhausts from zones 1 and 2.
    As described in the promulgation BID and supporting documentation, 
we determined that the environmental benefit of controlling additional 
conveyor dryer zones would not justify the cost for existing or new 
conveyor strand dryers.

[[Page 45966]]

2. Wood Products Press Enclosures
    Comment: Many commenters argued that EPA Method 204 compliance 
should not be a part of the PCWP MACT floor for presses because most of 
the press enclosures that were described in the industry survey data as 
having permanent total enclosures (PTE) were never certified by Method 
204 criteria. The commenters noted that most of these enclosures were 
designed according to Method 204 design criteria; however, the permits 
for these facilities never required them to comply fully with Method 
204 certification. The commenters contended that, of the 26 presses 
identified as having PTE, only 2 had actually undergone Method 204 
certification.
    The commenters also argued that Method 204 cannot be applied 
practically to the hot presses that are used at PCWP facilities. The 
commenters stated that Method 204 was developed for applications where 
the emissions have consistent properties; however, the temperature and 
density of emissions from a typical multiple-opening batch wood 
products press are constantly changing as the press opens and closes, 
which creates layers of gases with different physical properties within 
the enclosure. According to the commenters, instead of mixing and 
exiting the enclosure, the layers of gases can accumulate. The layers 
of gas in the upper region of the enclosure have a higher temperature 
and pressure than the air outside the press, and the lower layers of 
gas have a lower temperature and pressure than the air outside the 
press. The commenters maintained that to force the gases outside the 
enclosure, the operator would have to increase the airflow through the 
system to a rate that is three to four times higher than would be 
necessary for an enclosure operating at a homogenous temperature and 
pressure. The commenters contended that, while many of the wood 
products presses were designed to follow the Method 204 design 
criteria, they were not designed to overcome this phenomenon and may 
not be able to certify that all of the emissions are captured and 
contained.
    The commenters recommended that we address the press capture 
efficiency issue by implementing work practice requirements for 
enclosures. The commenters suggested that we replace the proposed 
definition of PTE with a definition that includes four of the five 
design criteria found in EPA Method 204, and replaces the requirement 
that ``all VOC emissions must be captured and contained for discharge 
through a control device'' with a requirement that ``fugitive emissions 
shall be minimized through appropriate operation and maintenance 
procedures applied to the PTE system.''
    Response: At proposal, we stated that the MACT floor determination 
for reconstituted wood products presses was based, in part, on the 
assumption that a sufficient number of these presses had enclosures 
that had been certified as PTE according to EPA Method 204. Presses 
equipped with Method 204 certified PTE would be allowed to claim 100 
percent capture efficiency, and thus, the rule requirements (e.g., 90 
percent emissions reductions) would effectively apply only to the 
captured emissions.
    Based on our review of available permit information, we agree with 
the commenters' assessment that few permits have required full Method 
204 certification for reconstituted wood products press enclosures, 
even though many of these press enclosures were constructed based on 
the Method 204 design criteria. We also agree that the nature of the 
batch pressing operations in the PCWP industry can make Method 204 
certification difficult. Unlike in the printing and publishing 
industry, for which Method 204 was originally developed, batch PCWP 
presses are heated, cyclical operations. Because of the internal 
pressurization within PCWP press enclosures, small amounts of fugitive 
emissions may appear around the outside of these enclosures. The 
percentage of press emissions that may be escaping from some of these 
enclosures has not been quantified but is expected to be small based on 
available information. We understand the commenters' concern that, due 
to the presence of these small amounts of fugitive emissions, 
facilities cannot certify that their Method 204 designed press 
enclosure can achieve all the Method 204 criteria, in particular the 
criteria in Method 204 section 6.2 which states that ``All VOC 
emissions must be captured and contained for discharge through a 
control device.'' While we feel that PCWP press enclosures should be 
designed to capture emissions under normal operating conditions, we do 
not feel it is necessary for PCWP facilities to increase the flow rate 
from their press enclosures (and the size of their APCD) three to four 
times to overcome the pressurization within the press enclosure. For 
the PCWP industry, we feel it would be particularly inappropriate to 
require such a large increase in exhaust flow to the APCD because the 
exhaust flows from PCWP process equipment, including presses, are 
already high volume, low concentration emission streams. High volume, 
low concentration exhaust streams generally are more costly to treat 
than low volume, high concentration emission streams. The best-
performing press enclosures that defined the MACT floor surround heated 
presses and are all expected to have pressurization within the press 
enclosure. In addition, we note that board cooler exhaust is sometimes 
directed into press enclosures and that enclosures around board coolers 
have not been certified according to EPA Method 204.
    Therefore, instead of requiring EPA Method 204 certification of 
PCWP press and board cooler enclosures as proposed, today's final rule 
sets forth slightly different criteria for press and board cooler 
enclosures. These criteria are based on the design criteria for PTE 
included in EPA Method 204, as recommended by the commenters; however, 
the criterion to capture and contain all VOC emissions has been 
replaced with a requirement that the enclosure be ``designed and 
maintained to capture all emissions for discharge through a control 
device.'' To effect this change, we removed references to PTE in the 
final rule and replaced the proposed definition of PTE with a new 
definition of ``wood products enclosure'' that lists the design 
criteria that must be met to comply with MACT. Enclosures that meet the 
definition of wood products enclosure do not have to test to determine 
the capture efficiency of these enclosures, but can assume 100 percent 
capture, such that the control requirements (e.g., 90 percent 
reduction) apply only to the captured emissions (i.e., the small amount 
of fugitive emissions outside the enclosure is disregarded).
    We also replaced the proposed definition of ``partial enclosure'' 
with a slightly revised definition of ``partial wood products 
enclosure'' to eliminate any references to PTE in the final rule. 
Because the capture efficiency of partial wood products enclosures is 
unknown, today's final rule requires facilities to test the capture 
efficiency of partial wood products enclosures using EPA Methods 204 
and 204A-F (as appropriate), or using the alternative tracer gas 
procedure included in appendix A to subpart DDDD of 40 CFR part 63. In 
addition, facilities have the option of using other methods for 
determining capture efficiency subject to the approval of the 
Administrator. As was proposed and suggested by the commenters, today's 
final rule requires facilities using partial wood products enclosures 
to demonstrate a combined 90 percent capture and control efficiency for 
those facilities showing

[[Page 45967]]

compliance with the percent reduction requirements for APCD. If the 
partial wood products enclosure does not achieve high capture 
efficiency, then facilities must offset the needed capture efficiency 
by achieving a higher destruction efficiency or with emissions 
averaging (with the press being an under-controlled process unit).
    Comment: One commenter objected to the proposed MACT floor for 
continuous presses and questioned the applicability of EPA Method 204 
to continuous presses. The commenter requested that we divide 
continuous and batch presses into two different process unit groups for 
the purpose of determining the MACT floor. The commenter provided 
information from environmental engineering firms and press 
manufacturers regarding the fundamental differences between the two 
types of presses. The commenter noted that continuous presses are much 
longer than batch presses, reaching lengths of 200 feet (ft), which 
makes them difficult to completely enclose. The commenter was unaware 
of any continuous presses that have Method 204 certified PTE. The 
commenter stated that enclosing a continuous press would cause 
operational problems, such as heat build-up and impaired visibility, 
which can lead to mechanical failures and unscheduled downtime. The 
commenter also cited potential safety concerns, such as increased fire 
risk and the possibility of unhealthy levels of HAP trapped inside the 
enclosure. The commenter further noted that the capital and operating 
costs of PTE applied to continuous presses would exceed those 
associated with batch presses due to the large size of the enclosure 
and the increased maintenance costs resulting from heat build-up within 
the enclosure. In addition, the commenter provided VOC emissions data 
based on measurements made at different points along the length of one 
of their continuous presses to demonstrate that emissions from the 
front stages are minimal and that the majority of emissions are from 
the last 40 percent of the press length, referred to as the 
``decompression zone.'' The commenter contended that gathering the 
emissions from all stages of the continuous press will result in a more 
dilute stream, which will be less cost-effective to treat, and that the 
large volume of exhaust to be treated would likely preclude the use of 
biofilters, which are more practical for treating smaller volumes of 
air.
    To remedy the situation, the commenter recommended that we divide 
batch and continuous presses into two different process unit groups for 
the purpose of determining the MACT floor. Because there are fewer than 
30 continuous presses, the MACT floor for existing continuous presses 
would be determined based on the average emissions limitation achieved 
by the five best-performing continuous presses. The commenter provided 
information to support the commenter's contention that none of the 
continuous presses achieved 100 percent capture and suggested that the 
MACT floor for capture efficiency is 80 percent capture of emissions 
from the decompression stages.
    Response: As explained in the proposal preamble, we based the MACT 
floor determinations for PCWP equipment on process units that are 
similar with respect to design, operation, and emissions. We 
acknowledge that continuous presses have a different design than 
multiopening batch presses. However, continuous presses have emissions 
that are within the same range as those from batch presses on a lb/MSF 
of board basis. Therefore, we feel it is reasonable to group batch and 
continuous presses together for purposes of determining the MACT floor. 
The MACT floor for continuous presses would be the same as the MACT 
floor for batch presses regardless of whether batch and continuous 
presses were placed in separate equipment groups. As explained below, 
we disagree that the MACT floor capture efficiency for continuous 
presses is 80 percent, as suggested by the commenter.
    The commenter was incorrect in suggesting that there are no 
continuous presses with Method 204 certified PTE. The two existing 
press enclosures in the PCWP industry identified as being Method 204 
certified surround continuous presses. The lengths of these two 
continuous presses are 41.5 ft and 110 ft. Due to the presence of these 
presses plus additional continuous presses equipped with total 
enclosures not certified via Method 204, the MACT floor for new and 
existing continuous presses is still a total enclosure and 
incineration-based control or biofilter, regardless of whether or not 
batch and continuous presses are treated as separate equipment groups. 
In addition, there is a Method 204 certified PTE around a 181-ft 
continuous press at a newer PCWP facility (which was not included in 
original data collection efforts and the pre-proposal MACT floor 
determination); however, this press has had some operational problems 
associated with its PTE. It is not clear if the operational problems 
experienced by this 181-ft-long press are the result of poor PTE design 
or inherent technical difficulties associated with enclosing long 
continuous PCWP presses.
    Long continuous presses are generally being installed at new PCWP 
facilities, as opposed to being retrofit at existing facilities. Given 
that there is at least one long continuous press (110 ft) with a Method 
204 certified PTE that has not experienced operational problems with 
its press enclosure, we feel that wood products enclosures (as defined 
in today's final rule) can be designed around long continuous presses. 
We recognize that higher cost may be associated with wood products 
enclosures around long continuous presses than for batch presses, but 
the CAA does not allow us to consider cost at the MACT floor control 
level.
    We note that enclosures greater than 200 ft in length are common in 
the printing/publishing industry. However, we do recognize there are 
differences in the enclosures used in the printing/publishing industry 
and those in the PCWP industry. Although not cyclical in operation like 
batch presses, continuous presses are heated operations and may also 
have internal pressurization issues similar to those raised by the 
commenters for batch presses. Therefore, we feel it is appropriate for 
the same definition of wood products enclosure promulgated for batch 
presses to apply to long continuous presses as well (as opposed to 
Method 204 certification).
3. MACT Floor Determinations of No Emissions Reductions
    Comment: Industry commenters supported our proposed MACT floor 
determinations of no emissions reductions for some process units, 
arguing our approach was fully consistent with applicable case law in 
the U.S. Court of Appeals for the D.C. Circuit. EPA properly determined 
that the average of the best-performing 12 percent of certain existing 
PCWP process units did not reflect the use of any control technology, 
and that no other universally applicable variables would affect HAP 
emissions, industry commenters stated. The commenters also claimed that 
EPA looked at pollution prevention (P2) measures and other approaches 
to determining the MACT floor, found none that are universally 
applicable, and therefore was permitted to base a no emissions 
reduction floor on the PCWP record.
    Response: As explained in the proposal preamble and supporting 
documentation, for those process units not required to meet the control 
requirements in the PCWP rule as proposed, we determined that: (1) the 
MACT floor level of control is no

[[Page 45968]]

emissions reductions, and beyond-the-floor control options are too 
costly to be feasible; or (2) insufficient information is available to 
conclude that the MACT floor level of control is represented by any 
emissions reductions. We based our MACT floor determinations for PCWP 
emission sources on the presence or absence of an add-on air pollution 
control device because we are not aware of any demonstrated P2 
techniques that can be universally applied across the industry, and we 
have no information on the degree of emissions reduction that can be 
achieved through P2 measures. Therefore, to our knowledge the use of 
add-on controls is the only way in which PCWP sources can currently 
limit HAP emissions, and the only way to identify the MACT floor for 
these sources is to identify a level that corresponds to that achieved 
by the use of add-on controls. When determining the MACT floor, we 
ranked the process units by control device rather than by actual unit-
specific emissions reductions because we have limited inlet/outlet 
emissions data. Based on the available information, we are not aware of 
any significant design or operational differences among each type of 
control system evaluated that would affect the ranking of process 
units. Furthermore, we are not aware of factors other than the type of 
control system used that would significantly affect the ranking of 
process units. An analysis of the available emissions data does not 
reveal any process variables that can be manipulated (without altering 
the product) to achieve a quantifiable reduction in emissions. Ranking 
process units according to control device, we determined that the MACT 
floor is no emissions reductions for several process unit groups 
including press predryers, fiberboard mat dryers, and board coolers at 
existing affected sources; and dry rotary dryers, veneer redryers, 
softwood plywood presses, hardwood plywood presses, engineered wood 
products presses, hardwood veneer dryers, humidifiers, atmospheric 
refiners, formers, blenders, rotary agricultural fiber dryers, 
agricultural fiber board presses, sanders, saws, fiber washers, 
chippers, log vats, lumber kilns, storage tanks, wastewater operations, 
miscellaneous coating operations, and stand-alone digesters at new and 
existing affected sources. As explained in the promulgation BID and 
supporting documentation, we also determined that beyond-the-floor 
control options are too costly for these process unit groups.
    At proposal, we requested comment on whether no emissions 
reductions for miscellaneous coating operations and for wastewater 
operations is appropriate (68 FR 1276, January 9, 2003). We also 
requested that commenters on this issue submit any information they 
might have on HAP or VOC emissions from miscellaneous coating 
operations and wastewater operations. However, no additional 
information on these operations was received from any of the commenters 
on the proposed rule. Following proposal, we reviewed our MACT analyses 
for miscellaneous coating and wastewater operations, as described in 
the following paragraphs and in the promulgation BID and supporting 
documentation. For miscellaneous coating operations, we gathered some 
additional information and were able to revise our conclusions 
regarding MACT in the absence of specific information on the emissions 
reduction achieved. However, we have no more reason to feel now than we 
did at proposal that PCWP wastewater operations are in fact subject to 
any emission control measures.
    Based on the available information, we have no basis to conclude 
that the MACT floor for new or existing sources is represented by any 
emission reductions for several of miscellaneous coating processes 
(i.e., anti-skid coatings, primers, wood patches applied to plywood, 
concrete forming oil, veneer composing, and fire retardants applied 
during forming), and we determined that there are no cost-effective 
beyond-the-floor measures to reduce HAP from these coating processes. 
However, some facilities reported use of water-based (non-HAP) coatings 
in their MACT survey responses for other types of coatings (including 
edge seals, nail lines, logo paint, shelving edge fillers, and 
trademark/gradestamp inks). Other facilities reported use of solvent-
based coatings for these processes. In some instances, a few 
respondents provided information on the percent HAP content of a 
solvent-based coating. Solvent-based coatings do not always contain HAP 
(e.g., the solvent may be mineral oil which does not contain HAP), and 
water-based coatings typically do not contain HAP. Thus, many of the 
coatings reported in the MACT survey responses are non-HAP coatings. 
While the emission reduction achieved as a result of coating 
substitutions cannot be determined, it is clear that use of non-HAP 
coatings represents the MACT floor because of the large number of 
facilities reporting use of non-HAP coatings. Beyond-the-floor options 
were not considered for edge seals, nail lines, logo paint, shelving 
edge fillers, and trademark/gradestamp inks because no further 
emissions reductions can be achieved than through use of non-HAP 
coatings. Based upon our revised MACT analysis, the final PCWP rule 
requires use of non-HAP coating for processes identified as group 1 
miscellaneous coating processes.
    The definition of non-HAP coating included in the final rule was 
based on the description of non-HAP coatings in the final WBP NESHAP 
(subpart QQQQ to 40 CFR part 63). This definition allows for 
unavoidable trace amounts of HAP that may be contained in the raw 
materials used to produce certain coatings. Through the definition of 
group 1 miscellaneous coatings in the final rule, kiln-dried lumber is 
excluded from the requirement to use non-HAP coatings because 
application of coatings used at kiln-dried lumber manufacturing 
facilities is not part of the PCWP source category. Although 
trademarks/gradestamps are applied to kiln-dried lumber, lumber kilns 
are the only processes at kiln-dried lumber manufacturing facilities 
covered under the PCWP source category.
    For wastewater operations, we concluded that we had insufficient 
information to conclude that the MACT floor level of control is 
represented by any emissions reductions. The available information on 
wastewater operations collected as part of the MACT survey of the PCWP 
industry and information contained in State permits indicated that 
these sources of emissions were not the subject of control requirements 
and were not expected to be significant sources of HAP or VOC 
emissions. As stated above, we received no comments containing 
additional information on emissions reduction measures or HAP/VOC 
emissions from wastewater operations. Thus, we have no more reason to 
feel now than we did at proposal that PCWP wastewater operations are in 
fact subject to any control measures. As a result, since no information 
shows that these PCWP operations use add-on controls, there is no 
identifiable numerical emissions level that would correspond to a MACT 
floor level reflecting the use of controls, and the only floor level 
demonstrable based on current data is no emissions reduction. 
Furthermore, given that our best data show that the emissions from 
wastewater operations are less than 1 ton/yr, we concluded that 
application of the control measures mentioned above would not be cost 
effective beyond-the-floor options. In response to the commenter's 
objection to the incompleteness of the data set for these PCWP 
operations, we note that the D.C. Circuit does not require EPA to 
obtain complete data as long as we are able to otherwise estimate the 
MACT floor

[[Page 45969]]

(Sierra Club v. EPA, 167 F.3d 658,662 (D.C. Cir. 1999)). Unlike dryers 
and presses at PCWP plants, wastewater operations have not been 
subjected by permitting authorities to controls for HAP emissions. We 
expended much effort in the early stages of the project gathering 
complete and accurate information on the PCWP processes with the most 
potential for HAP emissions and the greatest potential for emission 
control (i.e., the processes that have been the focus of permit 
requirements limiting HAP/VOC emissions) and the final PCWP rule 
addresses emissions from these process units.
    Had we been given reason to feel that there were emissions control 
measures associated with wastewater operations, we would have gathered 
more information for these processes earlier in the project. Even 
though we have determined that the current MACT floor for these PCWP 
operations is no emission reduction, since available information 
indicates they are not controlled, the HAP emissions from wastewater 
operations (and other PCWP sources with MACT determinations reflecting 
no emissions reductions) will be considered further when we review 
residual risk as required under section 112(f).

E. New Source MACT

    Comment: One commenter objected to our determination that MACT is 
the same degree of control for new and existing sources for many 
process units based on the fact that the best technology is the same 
for new and existing sources (i.e., incineration-based controls or 
biofilters). The commenter pointed out that, according to the proposal 
BID, the maximum percent control efficiency is in the upper 90s for 
THC, formaldehyde, and methanol. The commenter noted that the CAA 
requires the MACT floor to be based on the degree of emissions 
reduction achieved in practice by the best-controlled similar source. 
Thus, the commenter requested that we revise the new source MACT 
requirements for process units based upon the greatest reductions 
recorded.
    Response: As explained in the preamble to the proposed rule and 
supporting documentation, the MACT floor for both new and existing 
sources is based on the estimate of the performance achieved through 
application of RTO, RCO, or biofilters. We acknowledge that some 
incineration-based controls and biofilters can achieve greater than 90 
percent reduction in HAP or THC during a single performance test or a 
test run within a performance test. However, we also recognize that the 
percent reduction achieved can vary according to pollutant inlet 
concentration, a factor that is not directly controllable from a 
process or control device standpoint. Other unknown factors may also 
cause variability in control system performance. For example, we have 
THC percent reduction data for an RTO used to control emissions from 
three tube dryers and a press at an MDF plant for two emission tests 
conducted at different times. In 1996, the RTO achieved 92.7 percent 
reduction of THC, and in 1998 the same RTO achieved 98.9 percent 
reduction of THC. In addition, we have emissions test data for the same 
process unit and control system for multiple years, and these data show 
different emission factors, indicating that variability is inherent 
within each process unit and control system combination. Thus, we 
estimate that the best MACT technology achieves 90 percent HAP 
reductions when variations in operations and measurements are 
considered.

F. Definition of Control Device

    Comment: Several commenters requested that we add scrubbers and 
adsorbers to the proposed definition of ``control device'' and that 
condensers be omitted from the definition. One of the commenters 
operates a particleboard press that is equipped with a condenser that 
condenses steam from the press exhaust and then routes the condensate 
to an onsite wastewater treatment system. The remaining noncondensed 
gases are combusted in an onsite boiler as supplemental fuel. This 
commenter would like to be able to comply with the PBCO for 
reconstituted wood products presses rather than demonstrate compliance 
with one of the add-on control system compliance options (e.g., 90 
percent emissions reduction) or emissions averaging provisions; 
however, the commenter noted that PBCO only apply to uncontrolled 
emission sources. Therefore, the commenter requested that the 
definition of control device be limited only to those add-on control 
systems that were designed with HAP removal as the primary goal.
    Response: We disagree with the commenters that the proposed 
definition of control device should be changed. The definition in the 
final rule does not include scrubbers or absorbers but does include 
condensers and combustion units that incinerate process unit exhausts. 
For purposes of MACT standards development, the reason a control device 
is installed is immaterial. All control devices or techniques that 
reduce HAP emissions are considered when setting MACT standards. We 
note that the PBCO were developed and included in the PCWP rule for 
inherently low-emitting process units or process units with P2 
techniques and not for process units with add-on control systems. 
Therefore, the particleboard press equipped with the condenser and 
combustion unit described by the commenter cannot comply using the 
PBCO.
    In the proposed PCWP rule, we intentionally omitted absorbers 
(e.g., wet scrubbers) from the list of potential control devices 
because these technologies generally are not reliable for reducing HAP 
emissions. These wet systems may achieve short-term reductions in THC 
or gaseous HAP emissions; however, the HAP and THC control efficiency 
data, which range from slightly positive to negative values, indicate 
that the ability of these wet systems to absorb water-soluble compounds 
(such as formaldehyde) diminishes as the recirculating scrubbing liquid 
becomes saturated with these compounds. We wished to limit the examples 
included in the definition of control device to those devices for which 
we have data to demonstrate that they are effective in reducing HAP 
emissions from PCWP facilities. However, we note that the definition 
includes the phrase ``but not limited to'' and does not exclude other 
types of controls. We are aware that new technologies (some of which 
may be adsorption-based or absorption-based) may be developed that 
effectively reduce HAP emissions from PCWP sources. The definition of 
control device does not prevent their development or use.
    Facilities using wet scrubbers or WESP to meet the add-on APCD or 
emissions averaging compliance options can petition the Administrator 
for approval of site-specific operating requirements to be used in 
demonstrating continuous compliance. Alternatively, facilities using a 
wet scrubber or WESP may use a THC CEMS to show that the THC 
concentration in the APCD exhaust remains below the minimum 
concentration established during the performance test. In addition, 
facilities using wet control devices (e.g., wet scrubber or WESP) as 
the sole means of reducing HAP emissions must submit with their 
Notification of Compliance Status a plan for review and approval to 
address how organic HAP captured in the wastewater from the wet control 
device are contained or destroyed to minimize re-release to the 
atmosphere such that the desired emission reduction is obtained. 
Because wet scrubbers or WESP are add-on

[[Page 45970]]

APCD and have variable effects on HAP emissions, today's final rule 
specifies that sources cannot use add-on control systems or wet control 
devices to meet PBCO. As part of this change, we added a definition of 
``wet control device'' to today's final rule. We note that PCWP 
facilities demonstrating compliance with the PBCO for process units 
equipped with any wet control device that effects HAP emissions must 
test prior to the wet control device.

G. Compliance Options

1. Add-On Control System Compliance Options
    Comment: We received a number of comments related to the six add-on 
control systems compliance options and how these options might be 
implemented at an actual PCWP facility. One commenter argued that the 
use of multiple compliance options for add-on control systems will make 
it difficult for State agencies to determine if a facility is actually 
in compliance. The commenter pointed out that, if a facility tested for 
two options but passed only one, it would still be in compliance. 
However, the commenter stated that the rule as proposed was unclear 
whether a facility would be in violation if the facility chose to test 
for one option, failed that test, and then conducted another test to 
determine compliance with a different option. The commenter contended 
that this would constitute a violation of the standard, and any 
retesting to determine compliance with a different option would not 
reverse the initial violation. Therefore, the commenter requested that 
we clarify that the option to use the most beneficial results of two or 
more test methods applies only when these tests are conducted during a 
single performance test. According to the commenter, any facility that 
chose to use only one test method during the compliance test would have 
to accept the results of that test.
    Other commenters argued that a facility should be able to switch 
among the six add-on control options as needed to maintain compliance. 
To illustrate the necessity of the ability to switch from one add-on 
control option to another, the commenters provided an example whereby 
the operator of a veneer dryer might want to demonstrate compliance 
with the 90 percent THC reduction option (option 1 in Table 1B to the 
final rule) under certain operating conditions and with the 20 parts 
per million by volume (ppmv) THC option (option 2 in Table 1B to the 
final rule) under other operating conditions. One of the commenters 
also noted that production starts and stops and minor malfunctions are 
common at PCWP facilities, and most of them do not affect the 
performance of the air pollution control device. However, frequent SSM 
events resulting in a low concentration to the inlet of the control 
device could affect a facility's ability to comply with the percent 
reduction option. In this case, the commenter stated that the freedom 
to switch compliance options would be valuable. For these reasons, the 
commenters requested that we explicitly state in the final PCWP rule 
that ``a facility only need comply with any one of the six options at 
any one time, and that it can change between them as needed to fit 
process operating conditions.''
    Response: We understand the commenters' concerns on this issue and 
have written the final rule to clarify our intentions regarding how the 
add-on control system compliance options should be implemented at PCWP 
facilities. The proposed rule states at 40 CFR 63.2240 that ``You 
cannot use multiple compliance options for a single process unit.'' We 
included this provision to prevent PCWP sources from partitioning 
emissions from a single process unit and then applying different 
control options to each portion of the emissions stream. The MACT floor 
determinations and compliance options were all based on the full flow 
of emissions from process units, and therefore, compliance options 
should be applied to the same mass of emissions to ensure that the 
required MACT floor emissions reductions are achieved. When including 
this restriction, we did not intend necessarily to limit PCWP 
facilities to only one of the six options for add-on control systems. 
We did assume that each source would likely select only one option, and 
that at any point in time for purposes of assessing compliance, the 
given compliance option would have been pre-selected and reflected as 
applicable in the source's permit. In fact, in discussions with 
industry representatives prior to proposal, they expressed concern that 
the final rule be written to make it clear that a source would only 
have to comply with one option and not all six.
    Based on available data, we expect that most facilities will be 
able to demonstrate compliance with more than one of the compliance 
options for add-on control systems. When developing the six compliance 
options for add-on control systems, we felt that PCWP facilities would 
conduct emissions testing (e.g., inlet and outlet testing for THC, 
methanol, and formaldehyde over a range of APCD operating temperatures) 
and then, based on the results of testing, select the option that 
provides them with the most operating flexibility as well as an 
acceptable compliance margin (i.e., select the option that they feel 
will be easiest for them to meet on a continuous basis under varying 
conditions). The operating parameter limit to be reflected in the 
source's permit (e.g., minimum temperature) would be based on the 
measurements made during the compliant test runs. For example, if test 
results show that a facility can achieve 90 percent reduction for 
formaldehyde, 92 percent reduction for methanol, and 94 percent 
reduction for THC, then the facility may decide to reduce THC emissions 
by 90 percent, since this option appears to provide the greatest 
compliance margin. The corresponding operating parameter level measured 
during the testing (e.g., minimum 15-minute RTO temperature during a 
three-run test) would then be set as the operating limit in the permit 
for that source. In this example, if the RTO operating temperature 
drops below the operating limit, that would be a deviation, and any 
subsequent retesting done by the facility would presumably be done 
based on the chosen compliance option (e.g., reduce THC emissions by 90 
percent). Determining compliance in this case is relatively 
straightforward. However, we are aware that State agencies may simply 
refer to a NESHAP as part of a permit and not stipulate which 
compliance option the facility must meet. In these cases, we agree with 
the commenter who was concerned that compliance can be complicated when 
the referenced NESHAP contains multiple options, and that such a broad 
reference would not be adequate to identify the particular option (and 
parameter operating limits) applicable to the source. We also agree 
that, if a facility selects multiple options under the compliance 
options for add-on control systems, it should be required to conduct 
all necessary testing associated with compliance with the selected 
options concurrently. In addition the facility should obtain permit 
terms reflecting these options as alternate operating scenarios that 
clearly identify at what points and under what conditions the different 
options apply, such that compliance can be determined during a single 
time frame. For example, if the source wishes to include options 1, 3, 
and 5 in their permit, then it must perform inlet and outlet testing 
for THC, methanol, and formaldehyde any time the State agency has 
reason to require a repeat performance test (if all three options are 
simultaneously applicable) or test for the single applicable option

[[Page 45971]]

that corresponds to the given time and condition (if the options apply 
as alternate operating scenarios under different conditions). With this 
approach, we would avoid situations where a facility retests to 
determine compliance with a compliance option, fails to demonstrate 
compliance with that option, and then conducts additional testing to 
determine compliance with other options that are not pre-established as 
applicable at a later date.
    The final rule clarifies our intentions regarding the use of 
multiple control options with respect to add-on control systems versus 
the combining of control options for a single process unit. The 
language in 40 CFR 63.2240 of the final rule has been modified to 
remove the proposed text stating that a source ``cannot use multiple 
compliance options for a single process unit'' and replace it with a 
statement that a source ``cannot combine compliance options in 
paragraphs (a) [PBCO], (b) [add-on control systems compliance options] 
or (c) [emissions averaging provisions] for a single process unit.'' We 
feel that this wording change clarifies our intention to prevent 
sources from applying different control options to different portions 
of the emissions from a single process unit, while leaving open the 
potential for PCWP facilities to be able to include multiple compliance 
options for add-on control systems (i.e., one option per defined 
operating condition) in a State permit. Although add-on controls are 
used in emissions averaging plans to achieve full or partial control of 
emissions from a given process unit, the emissions from a single 
process unit cannot be parceled such that a portion of the emissions 
meets one of the add-on control system compliance options and another 
portion is used as part of an EAP. The final rule continues to state 
that sources must meet at least one of the six options for add-on 
control systems.
2. PBCO Limits
    Comment: Several commenters requested that PCWP facilities be 
allowed to use add-on control methods to achieve the PBCO limits. The 
commenters argued that allowing compliance with the PBCO using APCD is 
consistent with other MACT rules and P2 approaches. According to the 
commenters, numerous NESHAP allow emissions limits to be reached using 
add-on controls, P2 techniques, or a combination of both. The 
commenters stated that there was no legal or policy basis for imposing 
restrictions on the use of PBCO in the PCWP MACT. The commenters also 
stated that using add-on controls to comply with PBCO will benefit 
facilities that have process units that emit low levels of HAP. 
According to the commenter, some companies have already implemented P2 
strategies that have been established as BACT in a prevention of 
significant deterioration (PSD) permit. Because these P2 strategies may 
fall short of the PBCO, companies implementing these strategies would 
be unable to achieve compliance with the proposed rule without 
abandoning the P2 strategy and installing full control. The commenters 
also stated that incorporating add-on controls in the PBCO would 
provide incentives to find low-energy pollution control equipment. The 
commenters gave an example whereby part of the emission unit exhaust 
could be used as combustion air for an onsite boiler. The commenters 
noted that in most cases, the boiler could only handle a portion of the 
exhaust from multiple dryer stacks. The commenters stated that by 
combining this type of partial control approach with low-temperature 
drying, a facility may be able to meet the applicable dryer PBCO limit. 
According to the commenters, in this case, allowing for partial control 
would exclude the need for RTO technology and would provide a net 
benefit to the environment with a reduction of collateral oxidizer 
emissions. The commenters gave another example in which a facility with 
a conveyor strand dryer could send the exhaust from the first dryer 
section to a burner and then send the heat back to the dryer; the 
emissions from the remaining dryer sections would be uncontrolled if 
the total emissions were below the PBCO limit. In a third example 
provided by the commenters, a facility would remove enough HAP to 
comply with the PBCO limit using a scrubber, which would require less 
energy than incineration.
    Response: As in the proposed rule, the final rule does not allow 
sources to comply with the PBCO through the use of add-on control 
systems. Our intention for including the PBCO was to provide an 
alternative to add-on controls (e.g., allow for and encourage the 
exploration of P2, which currently has not been demonstrated as 
achieved by PCWP sources) and not to create another compliance option 
for sources equipped with add-on control systems that could 
inadvertently allow add-on control equipped systems to not perform to 
expected control efficiencies. Sources equipped with add-on control 
systems already have six different compliance options from which to 
choose, in addition to the emissions averaging compliance option. We 
note that the six options for add-on control systems are based on 
emissions reductions achievable with MACT control devices and thus are 
a measure of the performance of MACT control devices. This might not be 
true if a source combined PBCO and add-on controls, as explained below.
    At proposal, we established PBCO limits for 10 process unit groups. 
Initially, we felt that we needed total HAP data for at least one 
process unit in each process unit group that was equipped with a 
control system in order to establish the PBCO limits. However, we had 
to discard this approach because controlled total HAP data are not 
available for half (5 of 10) of the process unit groups. We developed a 
number of other approaches to establishing PBCO, and then compared the 
results of these approaches, where possible, with actual emissions in 
the outlet of MACT control devices. The approach that yielded results 
closest to actual emissions in the control device outlets was an 
approach based on a 90 percent reduction from the average emissions 
each process unit group. Thus, this approach was the one that resulted 
in limits that would most closely represent an alternative to the six 
compliance options for add-on control systems. However, our intention 
was not to develop an alternative limit to the six limits already 
established for add-on control devices. Our intention was to develop an 
alternative for P2 techniques. We decided to select an approach that 
allows sources that develop P2 techniques (or are otherwise inherently 
low-emitting sources) to comply and that reduces HAP emissions without 
generating the NOX emissions associated with incineration-
based controls. As a result, we selected a 90 percent reduction from 
the highest data point within each process unit group, because the 
results appeared to be at levels that would not preclude the 
development of environmentally beneficial P2 options as MACT.
    If PBCO were allowed as another option for measuring the 
performance of add-on control devices, operators could run the APCD so 
that the APCD would not achieve MACT level emissions reductions, but 
would meet the PBCO. We note that we did not develop the methanol and 
formaldehyde add-on control options (options 4 and 6 in Table 1B to the 
final rule) based on typical or maximum levels of methanol and 
formaldehyde found in the outlet of the control devices, but instead 
looked at the performance of the MACT control devices in reducing these 
HAP, set the levels based on the method detection limits for these 
compounds, and

[[Page 45972]]

included a minimum inlet concentration requirement for the use of the 
outlet concentration options to ensure that HAP emissions reductions 
are achieved. Allowing the use of APCD to comply with PBCO could allow 
circumvention of such optimization, which could render the MACT control 
itself to be less effective than MACT.
    Regarding the other MACT standards referenced by the commenters, we 
agree that these other rules may allow facilities more flexibility in 
meeting a production-based option (e.g., ``lb/ton'' emission limit); 
however, we cannot allow add-on controls to be used to meet the PBCO in 
the final PCWP rule because doing so would render these limits not 
equivalent to the other compliance options. For example, consider a 
typical wood products press with an annual production rate of 100 
million square feet of board per year and a total HAP emission rate of 
1.0 pound per thousand square feet of board on a \3/4\-inch basis (lb/
MSF \3/4\''). On an annual basis, the example press emits 50 tons of 
HAP per year. If the example press complies with the 90 percent HAP 
reduction requirement, then the HAP emissions reductions achieved will 
be at least 45 tons/yr. However, if this same press were allowed to 
comply with the applicable PBCO limit (0.30 lb/MSF \3/4\'') using an 
APCD (e.g., RTO), then the emissions reductions achieved could be as 
little as 35 tons/yr if the APCD is only applied to a portion of the 
press' emissions or if the APCD is not operated at MACT-level 
efficiency. Not only would a significantly lower HAP emission reduction 
be achieved in this situation, but there also would not be any net 
benefit to the environment to justify the lower HAP reduction (i.e., 
NOX emissions would still be created). Therefore, we feel it 
is appropriate and in keeping with the MACT floor to require PCWP 
process units with uncontrolled HAP emissions above the PBCO thresholds 
to achieve the full 90 percent reduction in emissions. We also wish to 
clarify that a PCWP facility may use any number of compliance options, 
as long as these options are not combined for an individual process 
unit. For example, a facility may choose to meet the applicable PBCO 
limit for one dryer, control emissions from a blender to avoid 
controlling emissions on the remaining two dryers as part of an 
emissions average, and comply with one of the add-on control systems 
compliance options for the press.
    Regarding the examples cited by the commenter as candidates for a 
PBCO if add-on controls were allowed, we note that the final rule 
includes a revised MACT floor for existing conveyor strand dryers, such 
that existing conveyor strand dryers that send the emissions from the 
first dryer section back to the combustion unit that heats the dryer 
should be able to meet the rule requirements without additional 
controls. In addition, partial control (e.g., routing part of the 
emission stream from a process unit to an onsite combustion unit for 
incineration) is allowed as part of an EAP as long as the actual 
emissions reductions achieved are greater than or equal to the required 
emissions reductions. When partial control is used as part of an EAP, 
the overall reductions are equivalent to what would be achieved if a 
source elected to comply using the add-on control system compliance 
options; however, the same would not be true if partial control were 
used to comply with a PBCO limit. Therefore partial incineration 
control is not allowed in the PBCO.
    Regarding the use of scrubbers to comply with a PBCO, as stated 
earlier in this preamble, the PCWP industry's own data do not support 
wet scrubbers as a reliable control technology for HAP, and sources 
equipped with wet control devices will be required to test prior to the 
wet control device if they elect to comply with a PBCO.
    Comment: Several commenters stated that PCWP facilities should be 
allowed to neglect nondetect HAP measurements for PBCO calculations. 
The commenters argued that if a facility is forced to use values of 
one-half the detection limit for nondetect HAP, that facility may be 
unable to use PBCO because the mass of emissions attributed to 
undetected compounds may consume 50 percent or more of the PBCO limit. 
The commenters also noted that the detection levels measured in the 
field by the NCASI test method, NCASI IM/CAN/WP-99.01, generally range 
between 0.35 and 1 ppm, and the detection levels of the FTIR method 
averages about 1 ppm. According to the commenters, even at these low 
concentrations, using one-half the detection limit for nondetect 
compounds can put the PBCO out of reach for a high-flow-rate PCWP 
stream. The commenters also provided a sample calculation to 
demonstrate the effect that the detection level has on the compliance 
calculation.
    Response: In responding to this request, we reviewed the 
information supplied by the commenters and analyzed the potential 
effects of making the requested change using available emissions data. 
After reviewing the total HAP data used to establish the PBCO limits, 
we decided that sources should be able to treat nondetect measurements 
for an individual HAP as zero for the sole purpose of determining 
compliance with the PBCO, if, and only if, the following two conditions 
are met: (1) The detection limit for that pollutant is set at a value 
that is less than or equal to 1 ppmvd, and (2) emissions of that 
pollutant are nondetect for all three test runs. We included the first 
condition to prevent test contractors from setting the detection limits 
too high, and thus generating false zeroes. We selected 1 ppmvd as the 
maximum detection limit value because it matches the detection limits 
achievable with the test methods included in the final PCWP rule. We 
included the second condition to ensure that the source is truly low-
emitting, as evidenced by three nondetect test runs. If emissions of 
the HAP are detected during any one test run, then any nondetect runs 
must be treated as being equal to one-half the detection limit. The 
option to treat nondetect measurements as zero does not apply to the 
compliance options for add-on control systems because treating the 
outlet emissions from a control device as zero would artificially 
increase the calculated control efficiency for that pollutant to 100 
percent.
    To ensure that the PBCO limits were developed in a manner 
consistent with how they would be applied, the PBCO limits were 
recalculated using zero for nondetect measurements when all test runs 
were nondetect. As a result, the PBCO limit for reconstituted wood 
product board coolers changed from 0.015 to 0.014 lb/MSF \3/4\''. No 
other PBCO limits changed as a result of using zero for nondetects when 
calculating the PBCO limits.
    We added a new PBCO limit to the final rule for secondary tube 
dryers. This new limit corresponds to our decision to treat primary and 
secondary tube dryers as separate process units, as discussed 
previously in this preamble. The final rule also differentiates between 
rotary strand dryers and conveyor strand dryers, as discussed 
previously in this preamble; however, no new PBCO limits have been 
added for these two process units groups. The final PBCO limit for 
rotary strand dryers is the same as the proposed limit for strand 
dryers because the data used to establish the proposed PBCO limit was 
based on data from rotary strand dryers exclusively. We do not have the 
necessary data to establish a PBCO for conveyor strand dryers, and thus 
the final rule does not include a PBCO limit for that process unit 
group.
3. Emissions Averaging Provisions
    Comment: Industry commenters generally expressed support for the

[[Page 45973]]

inclusion of an emissions averaging program in the PCWP rule as 
proposed, but requested that the proposed provisions be modified to 
allow for broader use of emissions averaging at PCWP facilities. 
Requested modifications include allowing sources to receive credit for 
achieving emissions reductions greater than 90 percent; basing 
compliance on a single pollutant; allowing sources to combine emissions 
averaging with PBCO; and allowing sources to receive credit for P2 
alternatives as part of an EAP.
    Response: We included an emission averaging compliance option in 
the proposed rule as an equivalent, more flexible, and less costly 
alternative to the compliance options for add-on control systems. 
Unlike previous MACT standards with emissions averaging, the proposed 
(and final) emissions averaging provisions in the PCWP rule do not 
include (1) limits on the number of sources that can be included in an 
emissions average, (2) requirements for a hazard or risk analysis, or 
(3) application of a 10 percent discount factor to emissions credit 
calculations. In addition, the emissions averaging provisions in the 
final PCWP rule require that credits for emissions reductions be 
achieved using APCD, and that the EAP be based on emissions of the six 
predominant HAP emitted from PCWP process units, referred to as total 
HAP. Also, the emissions averaging provisions do not allow credit for 
reductions beyond 90 percent.
    We disagree with the commenters' request to allow credit for 
achieving greater than 90 percent control of HAP as part of an EAP. We 
note that the 90 percent MACT floor level (upon which the emissions 
averaging provisions are based) reflects the inherent variability in 
uncontrolled emissions from PCWP process units and the decline in 
performance of control devices applied to these process units. The data 
set used to establish the MACT floor is composed of point-in-time test 
reports, some of which show a greater than 90 percent control 
efficiency; however, we selected 90 percent as the MACT floor level of 
control to reflect inherent performance variability. Therefore, it 
would be inappropriate to allow PCWP facilities to receive credit for 
similar point-in-time performance tests showing greater than 90 percent 
control, considering that the same types of control technologies would 
be used.
    Regarding the commenters' request to allow credit for greater than 
90 percent control for those sources with no MACT control requirements, 
we maintain that this would be inappropriate because the same issues of 
emissions variability and control device performance apply to those 
emission sources, and they likely would share control devices with PCWP 
process units that do have MACT control requirements.
    We have rejected the commenters' suggestion to base the emissions 
averaging provisions on a single pollutant (e.g., THC, methanol or 
formaldehyde), and retained the requirement in the final rule that the 
EAP must be based on total HAP. The predominant HAP emitted from a 
given process unit varies, with some process units emitting methanol as 
the predominant HAP and others emitting formaldehyde or acetaldehyde as 
the predominant HAP. However, the predominant HAP will always be one of 
the six we have identified in the definition of total HAP in the final 
PCWP rule. If we based the EAP on only one pollutant, process units 
that emit the target HAP in small quantities will not be correctly 
accounted for in the EAP, resulting in potentially less stringent 
control and greater potential risk than would result with other control 
options. As noted above, we did not include a hazard/risk study as part 
of the proposed EAP because we were requiring that the emissions 
reductions be based on total HAP, and PCWP process units generally emit 
the same six primary HAP, although in different quantities and ratios. 
Basing the EAP on a single pollutant would eliminate our rationale for 
not requiring a risk analysis. We also note that, while THC emissions 
are an acceptable surrogate for monitoring the performance of an add-on 
control device (same control device mechanisms that reduce THC 
emissions reduce HAP emissions), THC emissions are not an accurate 
surrogate for establishing baseline HAP emissions for uncontrolled 
process units, and thus the EAP should not be based solely on THC 
emissions. Although all PCWP process units emit THC, uncontrolled THC 
emissions from softwoods are substantially higher than from hardwoods 
due to non-HAP compounds (e.g., pinenes) present in softwoods. 
Therefore, allowing sources without add-on controls to focus on THC 
reductions achieved by increasing hardwood usage might reduce THC 
emissions but would have a minimal impact on HAP emissions. For these 
reasons, we feel that, for the purpose of the final rulemaking, THC 
should only be used as a surrogate for HAP when assessing the 
performance of an add-on control device, and should not be used as a 
surrogate for establishing the required and actual mass removal of HAP 
as part of an EAP.
    We disagree with the commenters that combining the emissions 
averaging option and PBCO will result in equivalent emissions 
reductions. As we stated in our response to previous comments in this 
section regarding PBCO, we developed the PBCO limits to provide an 
option for sources that develop P2 techniques. The PBCO limits 
represent applicability cutoffs such that sources with emissions below 
the applicable PBCO thresholds are not required to further reduce those 
emissions below MACT levels. By combining PBCO limits with the EAP, as 
proposed by the commenter, we would be allowing higher-emitting sources 
(i.e., those that cannot meet a PBCO and which should be controlled) to 
escape controls by artificially lowering their emissions (using the 
credits from the EAP) to levels that would qualify as low-emitting 
(below PBCO limits). This is counter to the intent of the PBCO and 
would result in lower emissions reductions than would be achieved 
without combining these two compliance options; therefore, this does 
not represent an option that is equivalent to the MACT floor and is not 
allowed in the final rule.
    We also disagree with the commenters' suggestion to modify the 
emissions averaging provisions to allow sources to receive credit for 
P2 projects because: (1) Compliance options (i.e., PBCO) already exist 
for any P2 projects that prove feasible, and (2) inclusion of currently 
undemonstrated P2 projects within EAP would unnecessarily complicate 
these plans and hamper enforcement. As we noted previously in this 
preamble, the final rule allows PCWP facilities to use both P2 (i.e., 
the PBCO) and emissions averaging at the same facility; sources are 
only limited in that they cannot apply both options to the same process 
unit. We also disagree with the commenters' assertion that quantifying 
the emissions reductions from P2 projects would not be difficult. 
Quantifying the emissions reductions associated with P2 projects has 
historically been a contentious issue, especially when a baseline 
emission level must be established from which to calculate the 
emissions reduction. We feel that the same issues apply for PCWP 
facilities, especially given the fact that P2 techniques have not been 
widely used or documented in the PCWP industry. In contrast, emissions 
reductions achieved through the use of add-on control systems are 
easily documented. The PBCO were established to address the future 
development and implementation of P2 techniques; however, the resultant

[[Page 45974]]

PBCO limits do not require that emissions reductions be determined. 
Instead, sources simply demonstrate that they are below the PBCO limit 
and will continue to operate in a manner that ensures they will remain 
below the PBCO limit.
    Regarding the suggested P2 option of increasing a facility's use of 
hardwood species, in addressing other issues, commenters stressed the 
difficulties associated with maintaining a consistent wood material 
flow in terms of species, moisture content, etc., which would suggest 
that an operating condition based on maintaining a set level of wood 
species would be unworkable. Furthermore, for veneer dryers, where 
species identification (hardwood vs. softwood), and thus enforcement, 
is fairly straightforward from the standpoint of both visual inspection 
and end-product, we have already established separate MACT floors for 
softwood and hardwood veneer dryers (and require no further emissions 
reductions from hardwood veneer dryers). When the end product is 
particleboard or MDF, and the raw material is in the form of wood 
chips, planer shavings, or sawdust, determining how much of that 
material is softwood versus hardwood would be very difficult, and 
likely unenforceable. Because of commenters' concerns that an operating 
condition based on wood species is technically unworkable and the 
associated enforcement issues, we feel this option is not viable.
    Regarding process changes such as reformulation, lowering dryer 
temperature, and routing process unit exhaust to existing combustion 
devices, the final rule already includes compliance options that would 
accommodate all of these strategies. For example, product reformulation 
and lowering dryer temperature are potential P2 options, and the PBCO 
limits would apply if the P2 efforts sufficiently lower emissions. The 
final PCWP rule distinguishes between green (high temperature, high 
moisture) rotary dryers and dry (low temperature, low moisture) rotary 
dryers and requires no further emissions reductions from dry rotary 
dryers. Regarding the use of existing combustion units as control 
devices, the final rule allows sources to route emissions to onsite 
combustion units for incineration. The final rule also allows sources 
to control a portion of a process unit's emission stream as part of an 
emissions average. However, we disagree that incineration of emissions 
in onsite process units is a P2 measure. Therefore, compliance with the 
PBCO using process incineration is not allowed in the final rule. The 
add-on control system and emissions averaging compliance options are 
available for process units controlled by routing exhaust to an onsite 
combustion unit.
    The final PCWP rule does not allow production curtailment to be 
counted as part of an EAP. As stated in the preamble to the proposed 
rule (68 FR 1276, January 9, 2003), we do not have facility-wide 
uncontrolled emissions data and facility-wide controlled emissions data 
for each PCWP facility to determine the baseline emissions and percent 
reduction in HAP achieved by each facility. Therefore, the MACT floor 
is not based on facility-wide emissions and emissions reductions 
achieved during year ``x.'' Instead, the MACT floor is based on (1) the 
presence or absence of certain MACT controls (in place as of April 
2000) on certain types of process units and (2) test data showing that 
these controls reduce emissions by greater than or equal to 90 percent. 
We applied the MACT floor methodology at the process unit level because 
we had the most accurate data at the process-unit level, making this 
approach the most technically and legally sound. The PCWP industry is 
very dynamic, with frequent shutdowns of equipment for maintenance, and 
occasionally longer shutdowns (e.g., month-long), if demand drops. The 
final PCWP rule requires emissions from specified process units at 
impacted PCWP facilities to be reduced by 90 percent, regardless of 
what the levels of emissions are for those facilities in a particular 
year. Therefore, implementation of the final PCWP rule at individual 
PCWP facilities will result in greater emissions reductions in years of 
greater production and lesser emissions reductions during years of 
lower production. As mentioned in the response to the previous comment, 
the emissions averaging provisions must achieve emissions reductions 
that are greater than or equal to those that would be achieved using 
the add-on control system compliance options, which specify which 
process units must be controlled. If we allowed credit for production 
curtailments, the overall emissions reductions achieved through the 
emissions averaging provisions would not be equivalent to what would be 
achieved through the use of the add-on control system compliance 
options, and therefore, the EAP would not be a MACT-equivalent 
alternative. For example, if we allowed production curtailments to 
count toward an emissions average, then a facility that shuts down one 
of two parallel production lines (each of which includes dryers and a 
press, plus HAP-emitting equipment that does not have associated 
control requirements) may not be required to control the emissions from 
any of the dryers or press on the remaining production line. However, 
if the same facility opted to comply with the add-on control system 
compliance options, then it would be required to control the press and 
dryer emissions from the remaining production line by 90 percent 
regardless of whether or not the other production line was shut down. 
In order to maintain equivalency between the emissions averaging 
provisions and the add-on control system compliance options and to 
preserve the required HAP emissions reductions, the final PCWP rule 
does not allow production curtailment to be counted as part of an EAP.
    Comment: One commenter objected to the inclusion of the emissions 
averaging option in the rule primarily because of the lack of a 
requirement to conduct a hazard or risk study. This commenter asserted 
that removing a certain mass of HAP regardless of identity is not 
equivalent to the other compliance options, and when the dose-response 
and exposure data are examined, it should be obvious that trading one 
HAP for another to meet a RMR is not an acceptable option. The 
commenter noted that there are currently no methods for weighting the 
toxicity of HAP and that the effects of simultaneous exposure to 
several HAP also are unknown.
    Response: We disagree with commenter's assertion that inclusion of 
the emissions averaging provisions will potentially increase toxic 
emissions at certain PCWP process units. As stated in the preamble to 
the proposed rule (68 FR 1289, January 9, 2003), PCWP facilities have 
fewer pollutants of concern (as compared to HON facilities) and are 
likely to have similar HAP emissions from the emission points (process 
units) that would be used to generate debits and credits. The PCWP 
facilities emit six primary HAP, whereas HON facilities may emit over 
140 different HAP. The PCWP facilities choosing to comply through 
emission averaging must account for the emissions of the six primary 
HAP (total HAP), which represent greater than 96 percent of the mass of 
HAP emitted from PCWP process units. Because the MACT control 
technologies are effective in reducing the emissions of all six of 
these HAP, and the emissions averaging provisions require the use of 
add-on control technologies for credit-generating sources in an EAP, we 
feel that the emissions averaging provisions will achieve a hazard/risk 
benefit

[[Page 45975]]

comparable to what would be achieved through point-by-point compliance. 
Although the final rule does not require a hazard/risk study, States 
will still have the discretion to require a PCWP facility that 
requested approval of an EAP to conduct a hazard/risk study (or could 
preclude the facility from using emissions averaging altogether).
    Comment: Several commenters requested that we write the definitions 
of some of the variables used in the emissions averaging equations in 
the final rule to clarify that sources can take credit for emission 
reductions achieved through partial control of debit-generating process 
units.
    Response: We agree with the commenters' request and have written 
the definitions of some of the variables used in the emissions 
averaging equations in today's final rule to clarify that partial 
credits generated from debit-generating process units that are 
undercontrolled can be included in the calculation of the AMR. For 
example, a PCWP facility may decide to control 30 percent of the 
emissions from a green rotary dryer and 80 percent of the emissions 
from a blender as part of an EAP in order to achieve a HAP reduction 
that is the same as or greater than what the facility would have 
achieved by controlling the green dryer emissions alone by 90 percent. 
In this example, the green rotary dryer is a debit-generating unit 
because it has MACT control requirements; however, the green dryer can 
receive credit in the AMR calculation for any partial emissions 
reductions that are achieved.

H. Testing and Monitoring Requirements

1. Test Methods
    Comment: Several commenters noted that one of the NCASI test 
methods, NCASI IM/CAN/WP-99.01, has been updated, and requested that 
the final rule refer to the revised version. One of the commenters 
provided a revised version of the method, identified as NCASI IM/CAN/
WP-99.02. This commenter noted that the trained NCASI sampling team was 
able to get good consistent results with the original version of the 
method both in the laboratory and in the field, but that sampling 
contractors had difficulty obtaining valid results. The commenter 
maintained that the revised version is easier to understand, includes 
more details, and reflects the comments of the contractors that have 
experience with the original method. The commenter also stated that the 
quality assurance requirements were strengthened in the revised version 
to ensure good results. Several commenters also noted that NCASI is 
currently developing a new method for measuring the six HAP (total HAP) 
listed in the PCWP rule as proposed. Therefore, the commenters 
requested that we include language in the final rule that would allow 
PCWP facilities to use future methods once they have been reviewed by 
EPA and have passed Method 301 validation at a PCWP plant.
    Response: We reviewed the revised NCASI method IM/CAN/WP-99.02 
supplied by the commenter and agree that the revised method is 
appropriate for measurement of the six HAP that comprise ``total HAP;'' 
therefore, we have included NCASI IM/CAN/WP-99.02 in the today's final 
rule. Regarding the development of future test methods, if and when a 
new method for measuring HAP from PCWP sources is developed and 
validated via EPA Method 301, we will issue an amendment to the final 
rule to include the use of that method as an alternative to the methods 
included in the final rule for measuring total HAP (i.e., NCASI Method 
IM/CAN/WP/99.02 and EPA Method 320--Measurement of Vapor Phase Organic 
and Inorganic Emission by Extractive FTIR). In the meantime, if the new 
method is validated using Method 301, then the Method 301 results can 
be used to request approval to use the new method on a site-specific 
basis.
    Comment: Several commenters noted that the tracer gas method for 
determining capture efficiency, developed by a PCWP company and 
included in the proposed rule (68 FR 1276, appendix A to 40 CFR part 
63), is a work in progress. These commenters included with their 
comments a copy of field validation tests conducted at a PCWP facility. 
The commenters noted that future tests are planned using the tracer gas 
method and that the results of these tests should help EPA improve the 
use and application of the proposed tracer gas test.
    Response: We have reviewed the results of the first field 
validation test of the tracer gas method and note that the commenters 
did not provide any specific recommendations for modifying the tracer 
gas method as it was proposed. Therefore, other than a few minor 
wording changes, we did not make any substantive changes to the tracer 
gas method in the final rule. If the results of subsequent field tests 
demonstrate a need to (further) modify the tracer gas method, we will 
issue an amendment to the final rule to incorporate the necessary 
changes.
2. Sampling Locations
    Comment: Several commenters recommended that the final rule be 
reworded to clearly state that inlet sampling should take place at the 
functional inlet of a control device sequence or at the primary HAP 
control device inlet. For example, the commenters noted that the final 
rule needs to clarify that sampling should take place at the inlet of a 
WESP that precedes an RTO instead of between the two devices. The 
commenters noted that many WESP-RTO control systems are too closely 
coupled to allow for a sampling location in between that meets the 
requirements of Method 1 or 1A, 40 CFR 60, appendix A.
    Response: We agree with the commenters and have written the final 
PCWP rule to indicate that, for HAP-altering controls in sequence, such 
as a wet control device followed by a thermal oxidizer, sampling sites 
must be located at the functional inlet of the control sequence (e.g., 
prior to the wet control device) and at the outlet of the control 
sequence (e.g., thermal oxidizer outlet) and prior to any releases to 
the atmosphere. In addition, as discussed previously in this preamble, 
the final rule also clarifies that facilities demonstrating compliance 
with a PBCO limit for a process unit equipped with a wet control device 
must locate the sampling site prior to the wet control device.
3. Testing Under Representative Operating Conditions
    Comment: Several commenters objected to the proposed requirement to 
test process units under representative operating conditions. The 
commenters argued that, because the initial compliance tests determine 
the outer limits of compliance, those tests should be conducted at the 
boundaries of expected performance for the process and control units. 
These commenters noted that testing at representative conditions would 
not accurately simulate true operating conditions, and thus, the 
operating parameter limits would be too narrow. Therefore, the 
commenters contended that the final rule should specify that initial 
compliance tests should be conducted at the extremes of the expected 
operating range for the parameter and control device function. In 
addition, one of the commenters noted that the testing provisions 
should also address potential conflicts with traditional State 
requirements to test at maximum or design conditions.
    Response: The proposed rule defined representative operating 
conditions as

[[Page 45976]]

those conditions under which ``the process unit will typically be 
operating in the future, including use of a representative range of 
materials[* * *] and representative temperature ranges.'' We disagree 
that the proposed requirement to test under representative operating 
conditions will conflict with State requirements and result in 
operating parameter limits/ranges that are too narrow. We wish to 
clarify that the definition of representative operating conditions 
refers to the full range of conditions at which the process unit will 
be operating in the future. We expect that facilities will test under a 
variety of conditions, including upper and/or lower bounds, to better 
define the minimum or maximum operating parameter limit or broaden 
their operating limit ranges (where applicable). For example, if a 
facility generally operates a process unit (equipped with an RTO) under 
conditions that require the RTO to be operated at a minimum temperature 
of 1450[deg]F to ensure compliance with the standards, but at other 
times operates that process unit under conditions such that the minimum 
RTO operating temperature must be 1525[deg]F to ensure compliance, then 
the facility has two options. One option is for the facility to 
incorporate both of these operating conditions into their permit such 
that they are subject to two different operating parameter limits 
(minimum temperatures), one for each (defined) operating condition. As 
an alternative, the facility could decide to comply with the parameter 
limit associated with the worst-case operating conditions (most 
challenging conditions for the RTO), which in this example would 
correspond to maintaining a minimum RTO operating temperature of 
1525[deg]F, and thus, they could demonstrate continuous compliance 
regardless of the operating condition as long as they maintained the 
RTO temperature at or above 1525[deg]F. We have revised the monitoring 
requirements for process units without control devices to allow these 
sources to establish a range of compliant parameter values. In 
addition, those PCWP facilities operating biofilters must maintain 
their biofilter bed temperature within the range established during the 
initial performance test and, if available, previous performance tests. 
If the final PCWP rule required testing at maximum operating 
conditions, there would be no way for facilities to identify their 
operating parameter ranges. For these reasons, we maintain that the 
requirement to test at representative operating conditions is 
appropriate for the PCWP rule.
4. Process Incineration Monitoring Requirements
    Comment: Several commenters expressed approval for the proposed 
exemption from testing and monitoring requirements for those process 
units with emissions introduced into the flame zone of an onsite 
combustion unit with a capacity greater than or equal to 44 megawatts 
(MW) (150 million Btu/hr). In addition, several of these commenters 
requested that we expand upon this exemption in the final rule. First, 
the commenters requested that we extend the exemption to include 
situations where the process unit exhaust is introduced into the 
combustion unit with the combustion air. The commenters noted that we 
had included such exemptions in the HON (40 CFR part 63, subpart G) and 
in the Pulp and Paper Cluster Rule (40 CFR part 63, subpart S) in 
recognition of the fact that boilers greater than 44 MW typically had 
greater than \3/4\-second residence time, ran hotter than 1,500[deg]F, 
and usually had destruction efficiencies greater than 98 percent (see 
65 FR 3909, January 25, 2000, and 65 FR 80762, December 22, 2000, at 
Sec.  63.443(d)(4)(ii)). The commenters stated that the design and 
construction of PCWP boilers follow the same principles that would 
allow for these operating conditions. Second, the commenters requested 
that we also exempt smaller combustion units (less than 44 MW, or 150 
million Btu/hr) from the testing and monitoring requirements if the 
process unit exhaust is introduced into the flame zone of the 
combustion unit. The commenters noted that most of the combustion units 
associated at PCWP facilities are smaller units and that testing of 
these units can be complicated by their configuration and integration 
with other process units.
    Response: After reviewing available information on process 
incineration at PCWP facilities, we decided to include smaller 
combustion units in the exemption from testing and monitoring 
requirements if the process exhaust enters into the flame zone. As part 
of this change, we have included definitions of ``flame zone'' and 
``combustion unit'' in the final rule. However, we decided not to 
include an exemption for PCWP combustion units that introduce the 
process exhaust with the combustion air. As noted by the commenters, 
the HON and the final pulp and paper MACT I rule exempt from testing 
and monitoring requirements combustion devices with heat input capacity 
greater than or equal to 44 MW. The HON also exempts from testing and 
monitoring combustion devices with capacity less than 44 MW if the 
exhaust gas to be controlled enters with the primary fuel. If the 
exhaust gas to be controlled does not enter with the primary fuel, then 
testing and continuous monitoring of firebox temperature is required by 
the HON. Similarly, the final pulp and paper MACT I rule exempts from 
testing and monitoring requirements combustion devices (including 
recovery furnaces, lime kilns, boilers, or process heaters) with 
capacity less than 44 MW if the exhaust stream to be controlled enters 
into the flame zone or with the primary fuel. Similar to the HON and 
pulp and paper MACT I rules, the final PCWP rule extends the exemption 
from testing and monitoring requirements to combustion units with heat 
input capacity less than 44 MW, provided that the exhaust gas to be 
treated enters into the combustion unit flame zone. If the exhaust gas 
enters into the combustion unit flame zone, the required 90 percent 
control efficiency may be assumed. If the exhaust gas does not enter 
into the flame zone, then the testing and monitoring requirements for 
thermal oxidizers will apply.
    As noted by the commenter, the HON and the final pulp and paper 
MACT I rule exempted boilers (and recovery furnaces at pulp and paper 
mills) with heat input capacity greater than 44 MW from testing and 
monitoring requirements because performance data showed that these 
large boilers achieve at least 98 percent combustion of HAP when the 
emission streams are introduced with the primary fuel, into the flame 
zone, or with the combustion air. Lime kilns at pulp and paper mills 
were excluded from this provision because we did not have any data to 
show that lime kilns can achieve the required destruction efficiency 
when the HAP emission stream is introduced with the combustion air. 
Therefore, lime kilns at pulp and paper mills that accept HAP emission 
streams must introduce the stream into the flame zone or with the 
primary fuel. We do not have the data to show that the design and 
construction of large (greater than 44 MW) combustion units at PCWP 
plants would be similar to boilers found at pulp and paper mills. 
Furthermore, combustion units at PCWP plants with heat input capacity 
of greater than 44 MW are less prevalent than smaller (i.e., less than 
44 MW) PCWP combustion units, and many of these smaller combustion 
units are not boilers. As stated above, the final rule exempts these 
smaller combustion units from the testing and monitoring requirements

[[Page 45977]]

provided that the HAP emission stream is introduced into the flame 
zone. For these reasons, the final PCWP rule does not extend the 
exemption from testing and monitoring to those boilers greater than 44 
MW that introduce the HAP emission stream with the combustion air.
5. Selection of Operating Parameter Limits for Add-On Control Systems
    Comment: Several commenters stated that the inlet static pressure 
to a thermal or catalytic oxidizer is not a reliable indicator of the 
flow through the oxidizer, the destruction efficiency, or the capture 
efficiency. The commenters also noted that the preamble to the PCWP 
rule stated that monitoring the static pressure can indicate to the 
operator when there is a problem such as plugging. However, the 
commenters stated that static pressure is usually the last indicator of 
these types of control device problems. As discussed in the 
promulgation BID, the commenters agreed that measuring those parameters 
helps to assess the overall condition of the oxidizer but provided 
reasons why setting limits on these parameters is inappropriate. The 
commenters further noted that monitoring the static pressure helps to 
control the speed of the fan or the oxidizer dampers so that all the 
air flows are balanced. According to the commenters, static pressure is 
adjusted to avoid vacuum conditions in the ductwork of multiple-dryer 
systems treated by one control device when one dryer is shut down, to 
improve emission collection efficiency and prevent fugitive emissions, 
and to adjust the pressure drop across a bag filter as it fills with 
particulates, among other reasons. However, the commenters stated that, 
if operators are required to keep the static pressure within an 
operating range, it will limit their ability to maintain capture 
efficiency. The commenters expressed similar concerns regarding air 
flow rate monitoring and noted that numerous factors affect the air 
flow through the control device, including the rate of water removal in 
dryers, leakage of tramp air into the process, the number of processes 
operating for control units that receive emissions from multiple 
production units, and the overall production speed due to process 
adjustments. The commenters noted that, in those cases where air flow 
to the oxidizer is not constant, monitoring the air flow through the 
oxidizer will not be an accurate measure of capture efficiency.
    Response: After reviewing the information provided by the 
commenters, we agree that, while monitoring the static pressure or air 
flow rate helps to assess the overall condition of the oxidizer and 
provides an indication that emissions are being captured, setting 
operating limits on these parameters is not appropriate for the reasons 
given by the commenters. Therefore, today's final rule does not include 
the proposed requirement to monitor the static pressure or air flow 
rate for thermal and catalytic oxidizers.
    Comment: Several commenters requested that we modify the procedures 
for determining the minimum operating temperature (operating limit) for 
thermal and catalytic oxidizers. The commenters stated that, due to the 
normal variation in combustion temperatures, a facility will have to 
perform the initial compliance test at lower-than-normal temperature 
conditions to ensure that the minimum combustion temperature will be 
set at a level that they can continuously meet. The commenters 
requested that we allow facilities to operate the thermal oxidizers up 
to 50[deg]F lower than the average obtained by the performance test and 
allow facilities to operate RCO at a level that is 100[deg]F above the 
minimum operating temperature of the catalyst. The commenters also 
noted that, when the THC concentration in the inlet is high, the RCO 
will not need any additional heat and it can operate at temperatures 
higher than the set point. Therefore, if the initial compliance tests 
are conducted under these conditions, the operating temperature limit 
will be too high for production rates at less than full capacity.
    Commenters also stated that, for RCO, the thermocouple should be 
placed in a location to measure the temperature of the gas in the 
combustion chamber between the catalyst beds instead of in a location 
to measure the gas stream before it reaches the catalyst bed. The 
commenters noted that, because the gas flow reverses direction in RCO, 
the inlet temperature monitor will not consistently measure the gas at 
the same point in the process such that sometimes the gas temperature 
will be recorded after the catalyst beds instead of before. The 
commenters further noted that placement of the monitor inside the 
combustion chamber would eliminate the need for multiple monitors and 
avoid problems such as overheating and burnout of the catalyst media 
caused by the temperature delay between the burner and the RCO inlet.
    Response: We disagree with the commenters' request to include a 
50[deg]F margin around the minimum operating temperature established 
during the thermal oxidizer compliance test. In general, selection of 
the representative operating conditions for both the process and the 
control device for conducting the performance test is an important, and 
sometimes complex, task. We maintain that establishing the add-on 
control device operating limit at the level demonstrated during the 
performance test is appropriate. We note that the PCWP rule as proposed 
allows a facility to select the temperature operating limits based on 
site-specific operating conditions, and the facility is able to 
consider the need for temperature fluctuations in this selection. The 
PCWP rule as proposed requires that the operating limit be based on the 
average of the three minimum temperatures measured during a 3-hour 
performance test (rather than on the average temperature over the 3-
hour period, for example) to accommodate normal variation during 
operation and ensure that the minimum temperature established 
represents the lowest of the temperatures measured during the compliant 
test. For example, during a 3-hour, three-run performance test, the 
operating limit would be determined by averaging together the lowest 
15-minute average temperature measured during each of the three runs. 
However, continuous compliance with the operating limit is based on a 
3-hour block average. For a typical 3-hour set of data, this means that 
the 3-hour block average will be higher than the average of the three 
lowest 15-minute averages, so the temperature monitoring provisions 
already have a built-in compliance margin. In addition, the final rule 
allows PCWP facilities to conduct multiple performance tests to set the 
minimum operating temperature for RCO and RTO, so PCWP sources would 
have the option to conduct their own studies (under a variety of 
representative operating conditions) in order to establish the minimum 
operating temperature at a level that they could maintain and that 
would provide them with an acceptable compliance margin. We feel these 
provisions allow sufficient flexibility, and an additional tolerance 
for a 50[deg]F temperature variation is not necessary. Therefore, the 
final rule does not allow facilities to operate thermal oxidizers 
50[deg]F lower than the average temperature during testing.
    With regard to RCO, we agree with the commenters that when the THC 
concentration in the inlet is high, the RCO will not need any 
additional heat and it can operate at temperatures higher than the set 
point. Therefore, if the initial compliance tests are conducted under 
these conditions, the operating temperature limit will be too

[[Page 45978]]

high for production rates at less than full capacity. However, the 
final rule requires emissions testing under representative operating 
conditions and not maximum operating conditions. In addition, we do not 
agree with the commenter's solution to set the operating limit at 
100[deg]F above the minimum operating (design) temperature of the 
catalyst. As with RTO, we feel it is incumbent upon the facility to 
demonstrate performance and establish the operating limits during the 
compliance demonstration test. Therefore, the final rule requires the 
facility to establish the minimum catalytic oxidizer operating 
temperature during the compliance test. However, as noted below, we 
have provided more flexibility to the facility regarding temperature 
monitoring for RTO and RCO.
    We recognize that in a typical RTO and RCO the combustion chamber 
contains multiple burners, and that each of these burners may have 
multiple thermocouples for measuring the temperature associated with 
that burner. The final rule requires establishing and monitoring a 
minimum firebox temperature for RTO. In an RTO, the minimum firebox 
temperature is actually represented by multiple temperature 
measurements for multiple burners within the combustion chamber. Thus, 
the final rule clarifies that facilities operating RTO may monitor the 
temperature in multiple locations within the combustion chamber and 
calculate the average of the temperature measurements to use in 
establishing the minimum firebox temperature operating limit.
    Regarding RCO, we agree with the commenters that, because the gas 
flow reverses direction in RCO, the inlet temperature monitor will not 
consistently measure the gas at the same point in the process, such 
that sometimes the gas temperature will be recorded after the catalyst 
beds instead of at the inlet to the beds. We did not intend to require 
the separate measurement of each inlet temperature by switching the 
data recording back and forth to coincide with the flow direction into 
the bed. The intention is to monitor the minimum temperature of the gas 
entering the catalyst to ensure that the minimum temperature is 
maintained at the operating level during which compliance was 
demonstrated. This can be accomplished by measuring the temperature in 
the regenerative canisters at one or more locations. Measuring the 
inlet temperatures of each catalyst bed and then determining the 
average temperature for all catalyst beds is one approach. Even though 
some of the beds are cooling and others are heating, the average across 
all of the catalyst beds should not vary significantly. Another 
acceptable alternative is monitoring the combustion chamber 
temperature, as suggested by the commenters. The monitoring location(s) 
selected by the facility may depend on the operating conditions (i.e., 
THC loading to the unit) during the performance test and how the unit 
is expected to be operated in the future. The objective is to establish 
monitoring and operating limits that are representative of the 
conditions during the compliance demonstration test(s) and 
representative of the temperature to which the catalyst is exposed. We 
recognize the need for flexibility in selecting the temperature(s) to 
be monitored as operating limits for RCO. Therefore, the final rule 
provides flexibility by allowing facilities with RCO to choose between 
basing their minimum RCO temperature limit on the average of the inlet 
temperatures for all catalyst beds or the average temperature within 
the combustion chamber. If there are multiple thermocouples at the 
inlet to each catalyst bed, then we would expect facilities to average 
the measurements from each thermocouple to provide a representative 
catalyst bed inlet temperature for each individual catalyst bed.
    Finally, the final rule also includes an option (in lieu of 
monitoring oxidizer temperature) for monitoring and maintaining the 
oxidizer outlet THC concentration at or below the operating limit 
established during the performance test. Use of the THC monitoring 
option would eliminate the concerns regarding establishing and 
monitoring oxidizer operating temperatures (in effect, it provides 
facilities complete flexibility in operation of the control device, as 
long as the THC outlet concentration remains below the operating 
limit).
    Comment: One commenter recommended that we require sampling and 
testing of the catalyst activity level for RCO. The commenter stated 
that the proposed requirement to monitor inlet pressure may not be 
sufficient to detect catalyst problems such as poisoning, blinding, or 
degradation.
    Response: We agree with the commenter that a catalyst activity 
level check is needed because catalyst beds can become poisoned and 
rendered ineffective. An activity level check can consist of passing an 
organic compound of known concentration through a sample of the 
catalyst, measuring the percentage reduction of the compound across the 
catalyst sample, and comparing that percentage reduction to the 
percentage reduction for a fresh sample of the same type of catalyst. 
Generally, the PCWP facility would remove a representative sample of 
the catalyst from the catalytic oxidizer bed and then ship the sample 
to a testing company for analysis of its ability to oxidize organic 
compounds (e.g., by a flame ionization detector).
    In response to this comment, we added to the final rule a 
requirement for facilities with catalytic oxidizers to perform an 
annual catalyst activity check on a representative sample of the 
catalyst and to take any necessary corrective action to ensure that the 
catalyst is performing within its design range. Corrective actions may 
include washing or baking out the catalytic media, conducting an 
emissions test to ensure the catalytic media is resulting in the 
desired emissions reductions, or partial or full media replacement. 
Catalysts are designed to have an activity range over which they will 
reduce emissions to the desired levels. Therefore, the final rule 
specifies that corrective action is needed only when the catalyst 
activity is outside of this range. It is not our intention for 
facilities to replace catalyst if the catalytic media is not performing 
at the maximum level it achieved when the catalyst was new. Also, the 
final rule specifies that the catalyst activity check must be done on a 
representative sample of the catalyst to ensure that facilities that 
may have recently conducted a partial media replacement do not sample 
only the fresh catalytic media for the catalyst activity check.
    Comment: Several commenters stated that the proposed operating 
requirements for pressure drop across the biofilter bed should be 
removed from the final PCWP rule. The commenters contended that 
pressure drop is a good parameter to monitor voluntarily because it 
indicates the permeability and age of the biofilter bed, helping to 
determine maintenance and replacement needs; however, it is not an 
indicator of destruction efficiency. The commenters noted that, because 
of normal wear and tear, the pressure drop gradually increases over the 
2- to 5-year life span of the biofilter, so it would not be possible to 
maintain a constant operating pressure. The commenters further noted 
that the supporting materials in the project docket did not provide any 
information or data that would support the idea that pressure drop is 
an indication of HAP destruction efficiency, but only indicated that 
pressure drop was an indication of the age of the biofilter. For these 
reasons, the commenters argued

[[Page 45979]]

that setting an absolute limit on pressure drop was inappropriate.
    The commenters also requested that the proposed requirements to 
monitor the pH of the biofilter bed effluent be removed from the final 
PCWP rule. The commenters noted that pH is a good parameter to monitor 
voluntarily because it indicates the environmental conditions inside 
the biofilter bed and can indicate the presence of organic acids and 
THC decomposition products, but it is not a reliable indicator of 
destruction efficiency. According to the commenters, small fluctuations 
of pH are expected and have little effect on the biofilter performance; 
therefore, the narrow range of pH values that would be established as 
an operating range by the initial compliance tests should not be used 
alone to determine biofilter performance. The commenters also noted 
some problems associated with continuous measurement of pH. According 
to the commenters, some biofilter units operate with periodic 
irrigation of the bed, such that the effluent flow is not constant and 
continuous monitoring is not possible. The commenters also pointed to 
an NCASI survey that confirmed that continuous pH monitoring would be 
impractical for the facilities surveyed. The commenters stated that, 
because none of the PCWP facilities surveyed could find a link between 
pH alone and biofilter performance, none of those facilities currently 
have continuous pH monitors on their biofilters.
    In addition, several commenters requested changes to the proposed 
requirement to monitor the inlet temperature of the biofilter. These 
commenters agreed that temperature is a parameter that should be 
monitored for biofilters, but argued that the location of the 
temperature monitor should be changed from the biofilter inlet to the 
biofilter bed or biofilter outlet. The commenters noted that the 
biofilter bed temperature has the greatest impact on biological 
activity. According to the commenters, the biofilter inlet temperature 
is not a good indicator of bed temperature and can change very rapidly 
depending upon the operating rate of the press, the humidity, and the 
ambient temperature.
    Response: We agree with the commenters that increases in pressure 
drop will occur over time and will not necessarily equate to a 
reduction in control efficiency, making an absolute limit on pressure 
drop ineffective in demonstrating continuous compliance. Therefore, we 
have not included the requirement to monitor pressure drop in the 
operating requirements for biofilters in the final PCWP rule. We have 
also removed the requirement to monitor pH from the final rule. 
Although pH is an indicator of the health of the microbial population 
inside the biofilter, we agree with the commenters that including 
continuous pH monitoring as an operating requirement for biofilters may 
not be appropriate.
    We also agree with the commenters that the biofilter bed 
temperature has the greatest impact on biological activity and that the 
location for monitoring the biofilter temperature should be changed. We 
did not propose monitoring of biofilter bed temperature because we 
thought that monitoring of biofilter inlet temperature would be simpler 
because only one thermocouple would be required. The temperature inside 
the biofilter bed can change in different areas of the bed, and 
therefore, depending on the biofilter, multiple thermocouples may be 
necessary to get an accurate picture of the temperature conditions 
inside the biofilter bed. Prior to proposal we rejected the idea of 
monitoring the biofilter exhaust temperature because temperature 
measured at this location can be affected by ambient temperature 
(especially for biofilters with short stacks) more than the temperature 
inside the biofilter bed. We now conclude that there is no better, more 
representative way to monitor the temperature to which the biofilter 
microbial population is exposed than to directly monitor the 
temperature of the biofilter bed. According to our MACT survey data, 
most facilities with biofilters are already monitoring biofilter bed 
temperature. Therefore, the final rule requires continuous monitoring 
of the temperature inside the biofilter bed.
    The proposed rule would have allowed facilities to specify their 
own monitoring methods, monitoring frequencies, and averaging times for 
the proposed biofilter operating parameters (i.e., inlet temperature, 
effluent pH, and pressure drop). However, monitoring of temperature is 
not as subjective as monitoring biofilter effluent pH and pressure 
drop; therefore, as an outgrowth of our decision to not require 
monitoring of biofilter effluent pH and pressure drop, the final rule 
specifies the monitoring method, frequency, and averaging time for 
biofilter bed temperature monitoring. The final rule requires that each 
thermocouple be placed in a representative location and clarifies that 
multiple thermocouples may be used in different locations within the 
biofilter bed. The temperature data (i.e., average temperature across 
all the thermocouples located in the biofilter bed if multiple 
thermocouples are used) must be monitored continuously and reduced to a 
24-hour block average. A 24-hour block average was selected for 
biofilter temperature monitoring because we recognize that there may be 
some diurnal variation in temperature. Facilities wishing to reflect a 
diurnal temperature variation when establishing their biofilter 
temperature may wish to perform some test runs during peak daily 
temperatures and other test runs early in the morning, when 
temperatures are at their lowest.
    Facilities may choose to observe parameters other than biofilter 
bed temperature, but will not be required to record or control them for 
the final PCWP rule. We feel that many factors can affect biofilter 
performance, either alone (e.g., a media change) or in concert with one 
another (e.g., a loss of water flow results in a sharp change in 
temperature and pH). The factors that have the greatest effect on 
biofilter performance are likely to be site-specific. However, based on 
the comments we have received, we conclude that extensive biofilter 
parameter monitoring is not the best method for ensuring continuous 
compliance. To promote enforceability of the final PCWP rule, we have 
added a requirement to perform periodic testing of biofilters. The 
final rule requires facilities to conduct a repeat test at least every 
2 years and within 180 days after a portion of the biofilter bed is 
replaced with a new type of media or more than 50 percent (by volume) 
of the biofilter media is replaced with the same type of media. Each 
repeat test must be conducted within 2 years of the previous test 
(e.g., 2 years after the initial compliance test, or 2 years after the 
test following a media change). We are requiring repeat testing after a 
partial or wholesale change to another media type (considered a 
modification of the biofilter) because such a modification can impact 
the performance of the biofilter. Facilities that replace biofilter 
media with a new type of media (e.g., bark versus synthetic media) must 
also re-establish the limits of the biofilter bed temperature range. We 
feel that substantial replacement of the biofilter media (e.g., 
replacement of more than 50 percent of the media) with the same type of 
media may affect short-term performance of the biofilter while the 
replacement media becomes acclimated, and therefore, the final rule 
requires a repeat performance test following this type of media 
replacement. However, PCWP facilities that replace biofilter media with 
the same type of media are not required to re-establish the biofilter

[[Page 45980]]

bed temperature range. In the case of same-media replacements, we feel 
it is appropriate for PCWP facilities to be able to use data from 
previous performance tests to establish the limits of the temperature 
range. During repeat testing following replacement with the same type 
of media, facilities can verify that the biofilter remains within the 
temperature range established previously or establish a new compliant 
temperature range. Facilities using a THC CEMS that choose to comply 
with the THC compliance options (i.e., 90 percent reduction in THC or 
outlet THC concentration less than or equal to 20 ppmvd) may use the 
data from their CEMS in lieu of conducting repeat performance testing.
    Comment: Several commenters requested that the final rule allow new 
biofilters a longer period than 180 days to establish operating 
parameter levels. These commenters suggested a 1-year period, because 
that would be long enough to observe the full seasonal variation in 
parameters and find the true operating maxima and minima.
    Response: We disagree that more than 180 days is necessary to 
establish operating parameter limits for biofilters. As mentioned 
previously, we have eliminated the proposed requirement to establish 
operating limits for pH and pressure drop. Today's final rule contains 
two options for biofilter operating parameter limits: biofilter bed 
temperature range and outlet THC concentration. While allowing 1 year 
to establish the biofilter bed temperature operating range is 
reasonable due to seasonal temperature variations, 1 year is not 
necessary for establishing an outlet THC concentration limit. 
Furthermore, the final rule already allows facilities to expand their 
operating ranges (see Sec.  63.2262(m)(3)) through additional emissions 
testing.
    The compliance date for existing facilities is 3 years after 
promulgation of the final PCWP rule, and existing facilities are 
allowed 180 days following the compliance date to conduct performance 
testing and establish the operating parameter limits. If there is 
concern that 180 days is not long enough for a new biofilter 
installation to operate under the full range of biofilter bed 
temperatures, then existing facilities should begin operation of their 
biofilter well before the compliance date (e.g., 180 days prior to the 
compliance date if 1 year is needed). Facilities also have the option 
of testing their biofilter prior to the compliance date to establish 
one extreme of their biofilter bed temperature range. The compliance 
date for new PCWP facilities is the effective date of the rule (if 
startup is before the effective date) or upon initial startup (if the 
initial startup is after the effective date of the rule), and 
biofilters installed at new PCWP facilities would have up to 180 days 
following the compliance date to establish the operating parameter 
limits. To address situations where a new biofilter is installed at an 
existing facility more than 180 days after the compliance date (e.g., 
to replace an existing RTO), we have included section Sec.  
63.2262(m)(2) to the final PCWP rule, which allows existing sources 
that install new biofilters up to 180 days following the initial 
startup date of the biofilter to establish the operating parameter 
limits. Thus, new biofilter installations are given time for 
establishment of operating parameter limits regardless of where they 
are installed at new or existing sources.
    Comment: Multiple commenters supported the option to continuously 
monitor THC at control device outlets to demonstrate compliance, but 
suggested that either the procedure for determining the operating 
limits or the length of the averaging periods be altered. The 
commenters stated that THC concentration at a control device outlet is 
not a parameter that can be easily adjusted by operators over short 
periods of time. The commenters stated that 3 hours is not a long 
enough block to avoid deviations from compliance given the variability 
of the process. The commenters provided an analysis of THC data from a 
biofilter outlet that showed multiple deviations occurring over a two 
month period when a 3-hour block average was used and few to zero 
deviations when a 24-hour or 7-day block average was used for the 
operating limits. The commenters stated that because HAP destruction 
efficiency of biofilters does not vary much with time, the longer block 
average would not be environmentally harmful.
    Response: While THC emissions at the outlet of a biofilter may 
vary, the THC emissions at the outlet of a thermal or catalytic 
oxidizer should not vary greatly. Although, as stated by the 
commenters, the HAP destruction efficiency of biofilters is not subject 
to large short-term variations, the same is not true for thermal and 
catalytic oxidizers (e.g., a sudden significant decrease in temperature 
could result in a sudden decrease in HAP reduction). Therefore, we feel 
it is appropriate to maintain the 3-hour block averaging requirement 
for THC monitoring for thermal and catalytic oxidizers. However, we 
have expanded the THC averaging requirement for biofilters to a 24-hour 
block average to provide more flexibility. The THC operating limit for 
biofilters would be established as the maximum of three 15-minute 
recorded readings during emissions testing. We also note the continuous 
monitoring of THC is not required for all APCD, but is an alternative 
to continuous monitoring of temperature. Furthermore, facilities can 
conduct multiple performance tests at different operating conditions to 
increase their maximum THC concentration operating limit.
6. Selection of Monitoring Requirements for Uncontrolled Process Units
    Comment: Several commenters recommended that we change the title of 
proposed Sec.  63.2262(n) (How do I conduct performance tests and 
establish operating requirements?--Establishing uncontrolled process 
unit operating requirements) to ``Establishing operating requirements 
for production-based compliance option process units'' for the final 
rule. The commenters stated that the proposed title implied that no 
controls of any kind are being applied to these process units, when in 
fact facilities may be using P2 techniques to reduce emissions. The 
commenters also objected to wording within the proposed section that 
suggests that temperature is the only parameter affecting HAP emissions 
from the process units. The commenters suggested that the requirements 
be revised in the final rule to give sources more flexibility in 
identifying and documenting those process unit operating parameters 
that are critical to maintaining compliance with the PBCO limits.
    Response: At proposal, our intention was to establish operating 
requirements for those process units complying with rule requirements 
without the use of an APCD. There are two situations in the PCWP rule 
as proposed where process units may not have an add-on control device: 
(1) When process units meet the PBCO, or (2) when process units used to 
generate emissions averaging debits do not have an add-on APCD that 
partially controls emissions. To clarify this for the final rule and to 
address the commenters' concern regarding applicability of Sec.  
63.2262(n), we changed the title of the section to ``Establishing 
operating requirements for process units meeting compliance options 
without a control device.''
    We agree with the commenters that temperature alone is not 
necessarily the sole factor affecting HAP emissions from some process 
units. A variety of factors can affect HAP emissions, and the 
controlling parameter for one process unit may be different than the 
controlling parameter for another process unit. Therefore, the final 
rule

[[Page 45981]]

gives sources more flexibility in selecting and establishing operating 
limits for process units without add-on controls. The final rule 
requires facilities to identify and document the operating parameter(s) 
that affect HAP emissions from the process unit and to establish 
appropriate monitoring methods and monitoring frequencies. We recognize 
that it is not practical to continuously monitor every process-unit-
specific factor that could affect uncontrolled emissions (e.g., there 
is no way to monitor and determine a 3-hour block average of wood 
species mix for a particleboard plant). However, some parameters are 
suitable for continuous monitoring (e.g., process operating 
temperature, furnish moisture content) and are already monitored as 
part of normal operation but not for compliance purposes. We feel that 
daily records of most parameters would be sufficient to ensure ongoing 
compliance (e.g., daily average process operating temperature, furnish 
moisture, resin type, wood species mix) if the parameters do not 
deviate from the ranges for these parameters during the initial 
compliance test. Therefore, in the final PCWP rule, we have replaced 
the proposed 3-hour block average temperature monitoring requirements 
for process units without control devices with a requirement to 
maintain, on a daily basis, the process unit operating parameter(s) 
within the ranges established during the performance test. This gives 
facilities the flexibility to decide which parameters they will monitor 
and control, while providing enforcement personnel with records that 
can be used to assess and compare the day-to-day operation of the 
process unit to the controlling operating parameters. Facilities are 
also allowed to decide for each parameter the appropriate monitoring 
methods, monitoring frequencies, and averaging times (not to exceed 24 
hours for continuously monitored parameters such as temperature and 
wood furnish moisture). Also, to ensure that the HAP emissions measured 
during the compliance tests are representative of actual emissions, the 
final rule requires testing at representative operating conditions, as 
defined in the rule.
7. Data Collection and Handling
    Comment: Several commenters requested clarifications and changes to 
the proposed requirements related to data collection and handling for 
CPMS. The commenters stated that the requirement that a valid hour of 
data must include at least three equally spaced data values for that 
hour is ambiguous and should be revised. The commenters recommended 
that the final rule require facilities to average at least three data 
points taken at constant intervals, provided the interval is less than 
or equal to 15 minutes. The commenters further noted that a better 
approach would be to drop the concept of an hourly average altogether 
and simply calculate the block average as the average of all evenly 
spaced measurements in the block period with a maximum measurement 
interval of 15 minutes. The commenters also noted that the proposed 
rule did not specify how to calculate the 3-hour block average when one 
or more of the individual hours does not contain at least three valid 
data values.
    Commenters also requested that the final rule consolidate and 
clarify the requirements in proposed Sec. Sec.  63.2268 and 63.2270 
regarding data that should be excluded from block averages. The 
commenters recommended that the final rule explicitly state that any 
monitoring data taken during periods when emission control equipment 
are not accepting emissions from the production processes should be 
excluded from hourly or block averages. The commenters also noted 
inconsistencies in the proposed rule language that seemed to imply that 
data collected during production downtime and SSM events would be 
included in the hourly averages but not in the block averages. The 
commenters stated that, because SSM events occur when the process is 
not in operation, there is no need to collect data from these periods.
    Response: We agree with the commenters that the proposed rule 
language regarding acceptable data and data averaging was somewhat 
ambiguous and have revised the language accordingly. Following the 
commenters' recommendation, we removed the concept of an hourly average 
from the final rule to allow block averages to be calculated as the 
average of all evenly spaced measurements in the 3-hour or 24-hour 
block period with a maximum measurement interval of 15 minutes. In 
place of the requirement for a valid hourly average to contain at least 
three equally spaced data values for that hour, we added a minimum data 
availability requirement. The minimum data availability requirement 
specifies that to calculate data averages for each 3-hour or 24-hour 
averaging period, you must have at least 75 percent of the required 
recorded readings for that period using only recorded readings that are 
based on valid data. The minimum data availability requirement appears 
in Sec.  63.2270(f) of today's final rule. To clarify what constitutes 
valid data and how to calculate block averages, we rearranged proposed 
Sec. Sec.  63.2268 and 63.2270. We moved proposed Sec.  63.2268(a)(3) 
and (4) to final Sec.  63.2270 (now Sec.  63.2270(d) and (e)) of 
today's final rule. Rather than repeating which data should be excluded 
from data averages in Sec.  63.2270(d) and (e), these new sections now 
refer to Sec.  63.2270(b) and (c) when discussing data that should not 
be included in data averages. We also added data recorded during 
periods of SSM to the list of data that should be excluded from data 
averages in Sec.  63.2270. We feel these changes to the structure and 
wording of the rule should fully address the commenters' concerns.
    Comment: Several commenters noted that the proposed PCWP rule does 
not provide any alternatives to the definition of a 1-hour period found 
in the MACT general provisions (40 CFR 63.2), which states that a 1-
hour period is any 60-minute period commencing on the hour. These 
commenters requested that facilities be given the option of beginning a 
1-hour period at a time that is convenient depending on shift changes, 
employee duties at the end of a shift, and settings on the systems that 
record data.
    Response: We agree with the commenters and have included a 
definition of 1-hour period in today's final rule that omits the phrase 
``commencing on the hour.''
8. Performance Specifications for CPMS
    Comment: Several commenters requested that we write sections of the 
final rule language that address temperature measurement. The 
commenters stated that the phrase ``minimum tolerance of 0.75 
percent,'' found in proposed sections 63.2268(b)(2), 63.2268(c)(3), and 
63.2268(e)(2), should be revised to read ``accurate within 0.75 percent 
of sensor range.'' The commenters argued that, because tolerances 
usually refer to physical dimensions, this revision more accurately 
reflects the intent of the final PCWP rule. Commenters also recommended 
that the sensitivity for chart recorders be changed from a sensitivity 
in the minor division of at least 20[deg]F to minor divisions of not 
more than 20[deg]F. The commenters noted that the wording in the 
proposed rule means that minor divisions could be 30[deg]F or 50[deg]F, 
but assumed that we probably meant that 20[deg]F is the largest minor 
division that a facility can use, and therefore, stated that the 
suggested revision is more accurate.
    Response: We agree that the proposed temperature measurement 
requirements should be clarified. In today's final rule,

[[Page 45982]]

we wrote the requirement in Sec.  63.2269(b)(2) (formerly proposed 
Sec.  63.2268(b)(2)) to read ``minimum accuracy of 0.75 percent of the 
temperature value.'' We eliminated proposed sections Sec. Sec.  
63.2268(c) and 63.2268(e) from the final rule because we removed the 
requirements for monitoring of pressure or flow. We also wrote proposed 
Sec.  63.2268(b)(3) to state that ``If a chart recorder is used, it 
must have a sensitivity with minor divisions of not more than 
20[deg]F.''
    Comment: Several commenters requested changes to the proposed work 
practice requirements for dry rotary dryers and veneer redryers related 
to moisture monitoring. The commenters noted that the proposed 
requirement to use a moisture monitor with a minimum accuracy of 1 
percent was appropriate for rotary dry dryers in the 25 to 35 percent 
moisture content range. However, the commenters stated that less 
stringent accuracy requirements should be included for veneer redryers 
to better correspond with current practices at softwood plywood and 
veneer facilities. Specifically, the commenters requested that the 
final rule revise the proposed performance specifications for moisture 
monitors for veneer redryers to allow the use of monitors with an 
accuracy of 3 percent in the 15 to 25 percent moisture 
range. Several commenters also requested that the proposed calibration 
procedures for moisture monitors be revised in the final rule to 
eliminate grab sampling and to allow facilities to follow the 
calibration procedures recommended by the manufacturer. The commenters 
argued that the proposed grab sampling procedure is impractical and 
that obtaining a representative grab sample would be difficult.
    Response: We agree with the commenters that the proposed moisture 
monitoring requirements should be adjusted in the final rule and have 
made the requested changes to the accuracy requirements for moisture 
monitors used with rotary dry dryers and veneer redryers. We have also 
adjusted the calibration procedures in the final rule to eliminate grab 
sampling and to allow facilities to follow the manufacturer's 
recommended calibration procedures for moisture monitors.

I. Routine Control Device Maintenance Exemption (RCDME)

    Comment: Several commenters requested that the proposed 
requirements for the RCDME be modified in the final rule to give PCWP 
facilities more flexibility. First, the commenters requested that the 
proposed RCDME allowances (expressed as a percentage of the process 
unit operating hours) be increased. The commenters argued that the 
proposed downtime allowance periods are too short to allow for proper 
maintenance. The commenters noted that the NCASI survey that was used 
to set the downtime allowance only included data from 1999, and many 
facilities may have conducted nonannual maintenance and repairs in the 
years preceding or following that year. According to the commenters, 
the 1999 survey was also limited in that the majority of the RTO 
included in the survey were less than 5 years old, and as the equipment 
ages over a lifetime of 5 to 15 years, performance will degrade below 
the levels seen in the 1999 survey. Therefore, the commenters suggested 
that we reexamine the NCASI downtime data and use the 79th percentile 
instead of the 50th percentile to select downtime allowances that 
represent the time needed for nonannual events.
    Response: After reviewing our previous analysis of the downtime 
data, we maintain that the percentage downtime we proposed (3 percent 
for some process units and 0.5 percent for others) calculated on an 
annual basis is appropriate for the final PCWP rule. The downtime 
allowance allowed under the RCDME is intended to allow facilities 
limited time to perform routine maintenance on their APCD without 
shutting down the process units being controlled by the APCD. We 
included the downtime allowance in the proposed rule because we 
recognize that frequent maintenance must be performed to combat 
particulate and salt buildup in some RTO and RCO for PCWP drying 
processes. The downtime allowance is not intended to cover every APCD 
maintenance activity, only those maintenance activities that are 
routine (e.g., bakeouts, washouts, partial or full media replacements) 
and do not coincide with process unit shutdowns. Most APCD maintenance 
should occur during process unit shutdowns; the RCDME is a downtime 
allowance in addition to the APCD maintenance downtime that occurs 
during process unit shutdowns. We note that most PCWP plants do not 
operate 8,760 hours per year without shutdowns. For example, the MACT 
survey responses indicate that softwood plywood plants operate for an 
average 7,540 hours per year, which would allow 1,220 hours for control 
device maintenance without the RCDME. Furthermore, the RCDME is allowed 
in addition to APCD downtime associated with SSM events covered by the 
SSM plan (e.g., electrical problems, mechanical problems, utility 
supply problems, and pre-filter upsets). For these reasons, the final 
rule retains the RCDME allowances included in the proposed rule.
    Comment: Several commenters objected to the proposed requirement 
that the maintenance be scheduled at the beginning of the semiannual 
period. The commenters argued that scheduling maintenance activities at 
the beginning of each semiannual period is neither consistent with 
industry practice nor practical. The commenters noted that downtime for 
maintenance is scheduled as the need arises, and downtime schedules 
change with need and production requirements. The commenters stated 
that most facilities have a general idea of when they intend to conduct 
routine maintenance activities and will schedule those activities 
whenever possible to coincide with process downtime as it approaches. 
The commenters further noted that the proposed PCWP rule does not 
clarify what would happen if maintenance were necessary before the 
scheduled date. Therefore, the commenters concluded that deleting the 
requirement to set the maintenance schedule at the beginning of each 
semiannual period would eliminate confusion and better represent 
industry practice.
    Response: We agree with the commenters and have removed the 
requirement to record the control device maintenance schedule for the 
semiannual period from the final rule. We agree that the proposed 
requirement would be impractical because process unit shutdowns are not 
scheduled semiannually. Also, the SSM provisions do not require 
scheduling of maintenance, and therefore, requiring scheduling of 
routine maintenance covered under the RCDME would be more restrictive 
than the requirements for SSM. To the extent possible, APCD maintenance 
should be scheduled at the same time as process unit shutdowns. Thus, 
today's final rule retains the requirement that startup and shutdown of 
emission control systems must be scheduled during times when process 
equipment is also shut down.
    Comment: Commenters also requested that the proposed RCDME 
requirement that facilities must minimize emissions to the greatest 
extent possible during maintenance periods be revised to require that 
facilities make reasonable efforts to minimize emissions during 
maintenance. The commenters stated that this revision is necessary 
because the proposed wording could be interpreted to mean that sources 
should limit production or shut down entirely

[[Page 45983]]

during maintenance periods, which is contrary to the intent of the 
RCDME.
    Response: We agree with the commenters and have modified the 
referenced requirement as suggested by the commenters.

J. Startup, Shutdown, and Malfunction (SSM)

    Comment: Several commenters noted inconsistencies between the 
proposed rule and the NESHAP General Provisions (40 CFR part 63, 
subpart A) and requested that these inconsistencies be resolved by 
making the final PCWP rule consistent with the latest version of the 
General Provisions.
    Response: Approximately 1 month prior to publication of the 
proposed PCWP rule, we published proposed amendments to the NESHAP 
General Provisions concerning SSM procedures (67 FR 72875, December 9, 
2002) and promulgated them in May 2003 (68 FR 32585, May 30, 2003). Due 
to the timing of the these rulemakings, the proposed PCWP rule language 
did not reflect our most recent decisions regarding SSM. To avoid 
confusion and promote consistency, we have written the final rule to 
reference the NESHAP General Provisions directly, where applicable, and 
to be more consistent with other recently promulgated MACT standards. 
Although the amendments to the NESHAP General Provisions regarding SSM 
plans are currently involved in litigation, the rule requirements 
promulgated on May 30, 2003, apply to the final PCWP NESHAP unless and 
until we promulgate another revision. In response to suggestions made 
by commenters, we also consolidated several sections to clarify the 
requirements related to SSM and to eliminate redundancies in the final 
rule. Specifically, we combined proposed Sec.  63.2250(d) with proposed 
Sec.  63.2250(a) and revised the resulting Sec.  63.2250(a) to clarify 
that the SSM periods mentioned in proposed Sec.  63.2250(a) apply to 
both process units and control devices and to clarify when the 
compliance options, operating requirements, and work practice 
requirements do and do not apply. We also removed proposed Sec.  
63.2250(e) from the final rule because it was a duplication of proposed 
Sec.  63.2251(e) regarding control device maintenance schedules. In 
addition, we removed proposed Sec.  63.2250(f) related to RCO catalyst 
maintenance because this section was misplaced and is not consistent 
with the RCO monitoring requirements in today's final rule.

K. Risk-Based Approaches

1. General Comments
Risk-Based Approaches
    Comment: Numerous commenters encouraged EPA to incorporate risk-
based options which would exclude facilities that pose no significant 
risk to public health or the environment. Commenters stated that 
inclusion of risk provisions has the potential to achieve overall 
environmentally superior results in a cost-effective manner, 
particularly in cases where criteria pollutants from control devices 
(i.e., incinerators) may result in greater impacts that the HAP 
emissions that they control. In particular, the commenter referred to 
EPA's projection that adoption of MACT floor level controls would 
result in increased emissions of NOX, a precursor to ozone 
and PM. According to the commenter, the proposed rule (without risk 
provisions) would work against the industry's voluntary commitment to 
reduce the emissions of greenhouse gases by 12 percent over the next 10 
years. The commenter concluded that, in its proposed form, the rule 
would impose significant additional cost with virtually no gain to 
either the environment or the health. The commenter stated that 
facilities wishing to take advantage of the risk-based exemption would 
take a federally-enforceable permit limit that would guarantee that 
their emissions remain below the risk-based emission standard. This 
would constitute an emission limitation, within the statutory 
definition of the term, and it would allow facilities to forego the 
installation of incinerators where they are not warranted by public 
health and environmental considerations, the commenter claimed.
    Some commenters argued that the risk-based options are legally 
justified, protective of human health and the environment, and 
economically sensible. These commenters stated that the risk-based 
options are supported under the CAA, through EPA's authority under 
sections 112(d)(4) and 112(c)(9) to set emission standards other than 
MACT for certain low-risk facilities and delist technology-defined low-
risk subcategories, respectively, and through what they claimed is 
EPA's inherent de minimis authority to avoid undertaking regulatory 
action in the absence of meaningful risk. One commenter pointed out 
that, by meeting the stringent health benchmarks necessary to qualify 
for the risk-based compliance approaches, facilities already would have 
satisfied the residual risk provisions 8 years ahead of the statutory 
requirements set forth in section 112(f) of the CAA.
    Two commenters believed that the risk-based approach would 
particularly benefit small mills located in rural areas with timber-
dependent economies. One commenter stated that, by offering 
manufacturers an opportunity to apply for subcategorization on a site-
specific basis, facilities that are remotely located, or which were 
originally planned and sited with thorough consideration of airshed 
impacts, would not be unduly burdened with MACT requirements which 
yield little or no public health benefits.
    Some commenters argued that such low-risk facilities should not be 
burdened with the requirements of MACT. One commenter noted that the 
regulatory framework exists within their State to implement a risk-
based approach. Another commenter agreed with the concept of a risk-
based approach but stated that it would not be appropriate for State 
and local programs to determine which facilities should be exempted 
from MACT. Another commenter suggested that exemptions be provided on a 
case-by-case basis to individual facilities that are able to 
demonstrate that they pose no significant risk to public health or the 
environment.
    Several commenters opposed the risk-based exemptions. Two 
commenters stated that the use of risk-based concepts to evade MACT 
applicability is contrary to the intent of the CAA and is based on a 
flawed interpretation of section 112(d)(4) written by an industry 
subject to regulation. One commenter added that the CAA requires a 
technology-based floor level of control and does not provide exclusions 
for risk or secondary impacts in applying the MACT floor. The other 
commenter was concerned about industry's unprecedented proposal to 
include de minimis exemptions and cost in the MACT standard process. 
The commenter stated that including case-by-case risk-based exemptions 
would jeopardize the effectiveness of the national air toxics program 
to adequately protect public health and the environment and to 
establish a level playing field. A third commenter noted that 
subcategorization and source category deletions under CAA section 
112(c) have been implemented several times since the MACT program 
began.
    Some commenters pointed out that they have not been able to comment 
on the technical merit of the risk analysis employed by the EPA. They 
argued that, until the residual risk analysis procedures have been 
implemented via the CAA section 112(f) process, risk

[[Page 45984]]

analysis should not be used in making MACT determinations pursuant to 
CAA section 112(d)(4). Also, risk analysis could never be used to 
establish a MACT floor.
    One commenter pointed out that, in separate rulemakings and 
lawsuits, EPA adopted legal positions and policies that they claimed 
refute and contradict the very risk-based and cost-based approaches 
contained in the proposal. In these other arenas, EPA properly rejected 
risk assessment to alter the establishment of MACT standards. The EPA 
also properly rejected cost in determining MACT floors and in denying a 
basis for avoiding the MACT floor.
    Response: We feel that the assertions by one commenter about the 
environmental disbenefits of the PCWP rule as proposed are overstated. 
We disagree that the PCWP industry as a whole poses a small-to-
insignificant risk to human health and the environment. However, we 
acknowledge that there are some PCWP affected sources that pose little 
risk to human health and the environment. Consequently, we have 
included an option in today's final PCWP rule that would allow 
individual affected sources to be found eligible for membership in a 
delisted low-risk subcategory if they demonstrate that they do not pose 
a significant risk to human health or the environment. The low-risk 
subcategory delisting in today's final PCWP rule is based on our 
authority under CAA sections 112(c)(1) and (9). The statute requires 
that categories or subcategories meet specific risk criteria in order 
to be delisted. To determine whether source categories and 
subcategories, and their constituent sources, meet these criteria, 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. Section 112(d)(1) of the CAA gives us the authority to 
distinguish among classes, types, and sizes of sources within a 
category, and CAA section 112(c)(1) does not restrict our authority to 
base categories and subcategories on other appropriate criteria. As 
discussed in more detail elsewhere in this notice, we feel these 
provisions of the CAA allow us to define a subcategory of sources in 
terms of risk. Thus, the low-risk subcategory of PCWP affected sources 
is defined in terms of risk, not cost. We are not subcategorizing or 
determining MACT floors based on cost. Furthermore, because most 
affected sources will make their low-risk demonstrations following 
promulgation of today's final PCWP rule, the MACT level of emissions 
reduction required by today's final rule is not affected by affected 
sources becoming part of the low-risk subcategory.
    We are not pursuing the risk-based exemptions based on CAA section 
112(d)(4). We do not feel that a risk-based approach based on section 
112(d)(4) is appropriate for the PCWP industry because PCWP facilities 
emit HAP for which no health thresholds have been established and 
because the legislative history of the 1990 Amendments to the CAA 
indicates that Congress considered and rejected allowing us to grant 
such source-specific exemptions from the MACT floor. We also are not 
relying on de minimis authority. Legal issues associated with the risk-
based provisions are addressed elsewhere in this preamble.
    In today's final PCWP rule, we are identifying the criteria we will 
use to identify low-risk PCWP affected sources and requesting that any 
candidate affected sources, in addition to the affected sources already 
identified as low risk in today's action, submit information to us 
based on those criteria so that we can evaluate whether they might be 
low-risk. Today's final PCWP rule also establishes a low-risk PCWP 
subcategory based on the criteria (and including several identified 
affected sources) and delists the subcategory based on our finding that 
no source that would be eligible to be included in the subcategory 
based on our adopted criteria emits HAP at levels that exceed the 
thresholds specified in section 112(c)(9)(B) of the CAA. To be found 
eligible to be included in the delisted source category, affected 
sources will have to demonstrate to us that they meet the criteria 
established by today's final PCWP rule and assume federally enforceable 
limitations that ensure their HAP emissions do not subsequently 
increase to exceed levels reflected in their eligibility 
demonstrations.
    The criteria defining the low-risk subcategory of PCWP affected 
sources are included in appendix B to subpart DDDD of 40 CFR part 63. 
The criteria in the appendix were developed for and apply only to the 
PCWP industry and are not applicable to other industries. Today's final 
PCWP rule provides two ways that an affected source may demonstrate 
that it is part of the low-risk subcategory of PCWP affected sources. 
First, look-up tables allow affected sources to determine, using a 
limited number of site-specific input parameters, whether emissions 
from their sources might cause a hazard index (HI) limit for 
noncarcinogens or a cancer benchmark of one in a million to be 
exceeded. Second, a site-specific modeling approach can be used by 
those affected sources that cannot demonstrate that they are part of 
the low-risk subcategory using the look-up tables.
    The low-risk subcategory delisting that is included in today's 
final PCWP rule is intended to avoid imposing unnecessary controls on 
affected sources that pose little risk to human health or the 
environment. Facilities will have to select controls or other methods 
of limiting risk and then demonstrate, using appendix B to subpart DDDD 
of 40 CFR part 63 and other analytical tools, such as the ``Air Toxics 
Risk Assessment Reference Library,'' if appropriate in a source's case, 
that their emissions qualify them to be included in the low-risk 
subcategory, and, therefore, to not be subject to the MACT compliance 
options included in today's final PCWP rule.
    Comment: Several commenters objected to EPA using the preambles of 
individual rule proposals as the forum for introducing significant 
changes in the way that MACT standards are established. The commenter 
believed that allowing risk-based exemptions requires statutory 
changes. A third commenter expressed concern that other parties may 
miss commenting on the risk-based exemptions because they are contained 
within six separate proposals. The commenter added that to give the 
issue full consideration, the risk provisions should not be adopted 
within any of the final rules but should be addressed in one place, 
such as in revisions to the General Provisions of 40 CFR part 63, 
subpart A.
    Response: The discussion of risk-based provisions in MACT was 
included in individual proposals for several reasons. First, we 
recognize that such provisions might only be appropriate for certain 
source categories, and our decision-making process required source 
category-specific input from stakeholders. Second, the 10-year MACT 
standards, which are now being completed, are the last group of MACT 
standards currently planned for development, and for any risk 
provisions to be useful, the provisions must be finalized in a timely 
manner. We do not agree that statutory changes are necessary because of 
the discretion provided to the Administrator under CAA section 
112(d)(1) to distinguish among classes, types, and sizes of sources 
within a category and under CAA section 112(c)(1) to base categories 
and subcategories on any appropriate criteria. We consider low-risk 
affected

[[Page 45985]]

sources to be an appropriate subcategory of sources within the PCWP 
source category.
    Comment: Several commenters stated that the risk-based exemption 
proposal removes the level playing field that would result from the 
proper implementation of technology-based MACT standards. According to 
the commenters, establishing a baseline level of control is essential 
to prevent industry from moving to areas of the country that have the 
least stringent air toxics programs, which was one of the primary goals 
of developing a uniform national air toxics program under section 112 
of the 1990 CAA amendments. The commenters argued that risk-based 
approaches would jeopardize future reductions of HAP in a uniform and 
consistent manner across the nation. One commenter stated that National 
Air Toxics Assessment (NATA) data show that virtually no area of the 
country has escaped measurable concentrations of toxic air pollution. 
The NATA information indicates that exposure to air toxics is high in 
both densely populated and remote rural areas.
    One commenter disagreed with the assertion that the level playing 
field would be removed. The commenter pointed out that the argument 
that EPA should impose unnecessary and potentially environmentally 
damaging controls for the sole purpose of equalizing control costs 
across facilities would be at odds with the stated purpose of the CAA. 
According to the commenter, the claim that the risk-based approach 
would favor facilities located away from population centers is 
incorrect. As contemplated, the risk-based approaches to the NESHAP 
would be keyed to the comparison of health benchmarks with reasonable 
maximum chronic and acute exposures. According to the commenter, the 
presence or absence of human populations would have no effect on 
whether facilities would qualify.
    Response: We agree that one of the primary goals of developing a 
uniform national air toxics program under section 112 of the 1990 CAA 
amendments was to establish a level playing field. We do not feel that 
defining a low-risk subcategory in today's final PCWP rule does 
anything to remove the level playing field for PCWP facilities. Today's 
final PCWP rule and its criteria for demonstrating eligibility for the 
delisted low-risk subcategory apply uniformly to all PCWP facilities 
across the nation. Today's final PCWP rule 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. 
The criteria for the low-risk subcategory are not dependent on local 
air toxics programs. Therefore, concerns regarding facilities moving to 
areas of the country with less-stringent air toxics programs 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).
    Comment: One commenter stated that the dockets for the MACT 
proposals that contain the risk approaches make it clear that the White 
House Office of Management and Budget (OMB) and industry were the 
driving forces behind the appearance of these unlawful approaches in 
EPA's proposals. The commenter condemned the industry-driven agenda 
that it claimed is being promoted by the White House OMB.
    A second commenter stated that the accusations that EPA succumbed 
to industry lobbying and internal pressures are entirely unfounded.
    Response: We are required by Executive Order 12866 to submit to OMB 
for review all proposed and final rulemaking packages that would have 
an annual effect on the economy of $100 million or more. The comments 
we received from OMB reflect their position that low-risk facilities do 
not warrant regulation. However, the commenter is incorrect in implying 
that we have not exercised our independent judgment in addressing these 
issues. Our rationale for adopting the risk-based approach in this PCWP 
rulemaking is that such an approach is fully authorized under the CAA. 
This rule reflects the EPA Administrator's appropriate use of 
discretion to use CAA section 112(c)(9) to delist a low-risk 
subcategory.
Effects on MACT Program
    Comment: Several commenters expressed concern about the impact of a 
risk-based approach on the MACT program. Some commenters stated that 
the proposal to include risk-based exemptions is contrary to the 1990 
CAA Amendments, which calls for MACT standards based on technology 
rather than risk as a first step. The commenters pointed out that 
Congress incorporated the residual risk program under CAA section 
112(f) to follow the MACT standards, not to replace them. One commenter 
added that risk-based approaches would be used separately to augment 
and improve technology-based standards that do not adequately provide 
protection to the public.
    Another commenter believed that CAA section 112(d)(4) and the 
regulatory precedent established in over 80 MACT standards reject the 
inclusion of risk in the first phase of the MACT standards process. The 
commenter argued that the use of risk assessment at this stage of the 
MACT program is, in fact, directly opposed to title III of the CAA.
    Response: We disagree that inclusion of a low-risk subcategory in 
today's final PCWP rule is contrary to the 1990 CAA Amendments. The 
PCWP MACT rule is a technology-based standard developed using the 
procedures dictated by section 112 of the CAA. The only difference 
between today's final PCWP rule and other MACT rules is that we used 
our discretion under CAA sections 112(c)(1) and (9) to subcategorize 
and delist low-risk affected sources, in addition to fulfilling our 
duties under CAA section 112(d) to set MACT. The CAA requires that 
categories or subcategories meet specific risk criteria, 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. We feel that today's 
final PCWP rule is particularly well-suited for a risk-based option 
because of the specific pollutants that are emitted by PCWP sources. 
For many affected sources, the pollutants are emitted in amounts that 
pose little risk to the surrounding population. However, the cost of 
controlling these pollutants is high, 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 today's final PCWP rule defining the delisted low-
risk subcategory are based on sufficient information to develop health-
protective estimates of risk and will provide ample protection of human 
health and the environment.
    Inclusion of a low-risk subcategory in today's final PCWP rule does 
not alter the MACT program or affect the schedule for promulgation of 
the remaining MACT standards. We recognize that such provisions are 
only appropriate for certain source categories, and our decision-making 
process required source category-specific input from stakeholders. The 
10-year MACT standards, which are now being completed, are the last 
group

[[Page 45986]]

of MACT standards currently planned for development, and for any risk 
provisions to be useful, the provisions must be finalized in a timely 
manner.
    Comment: Several commenters stated that the inclusion of a risk-
based approach would delay the MACT program and/or promulgation of the 
PCWP MACT standard. If the proposed approaches are inserted into 
upcoming standards, the commenters feared the MACT program (which is 
already far behind schedule) would be further delayed.
    One commenter stated that they were strongly opposed to returning 
to the morass of risk-based analysis in an attempt to preempt the 
application of technology-based MACT standards and exempt facilities. 
The commenter stated that designing a risk-based analysis procedure 
would also take significant resources, as evidenced by the fact that it 
took five plus pages in the Federal Register to discuss just the basic 
issues to be considered in the analysis. The commenter indicated that 
the demand on government resources could cause a delay in the 
application of MACT nationwide. The commenter stated that EPA should 
also consider the issue of fairness since the rest of the industrial 
sector whose NESHAP have already been promulgated did not have a risk-
based option.
    Another commenter stated that it is evident that the proposed risk-
based exemptions would require extensive debate and review in order to 
launch, which would further delay promulgation of the remaining MACT 
standards. The commenter stated that delays could be exacerbated by 
litigation following legal challenges to the rules, and such delays 
would trigger the CAA section 112(j) MACT hammer provision, which would 
unnecessarily burden the State and local agencies and the industries. 
The commenter concluded that, obviously, further delay is unacceptable. 
Another commenter agreed, stating that it is imperative that EPA meet 
the new deadlines for promulgating the final MACT standards.
    Two commenters stated that EPA's proposal to improperly incorporate 
risk assessment into the technology-based standard process would 
cripple a MACT program already in disarray. The commenters argued that 
the risk-based approach could exacerbate the delay in HAP emissions 
reductions required by CAA section 112. One commenter noted that EPA's 
Office of Inspector General recently found that EPA is nearly 2 years 
behind in fulfilling its statutory responsibilities for implementing 
Phase 1 MACT standards. According to the commenter, this delay 
potentially harms the public and environment. The inclusion of risk-
based exemptions in 10-year MACT standards would only further delay 
this process. The other commenter noted that EPA lacks adequate 
emissions and exposure data, source characterization data, and health 
and ecological effects information to conduct this process anyway. This 
commenter believed that the air toxics program is flawed and failing to 
protect public health and the environment and argued that it was 
irresponsible for EPA to pursue a deregulatory agenda that would 
further weaken the effectiveness of the air toxics program. The 
commenter noted that EPA acknowledged the complexity and delays 
associated with the proposed risk-based approaches in deciding not to 
adopt the approaches in the final BSCP rule.
    Response: We disagree that identification and delisting of a low-
risk subcategory in today's final PCWP rule will alter the MACT program 
or affect the schedule for promulgation of the remaining MACT 
standards, especially the PCWP MACT rule. In fact, it has not caused 
such a delay for the final rule. We do not anticipate any further 
delays in completing the remaining MACT standards. The delisting of a 
low-risk subcategory in today's final PCWP rule affects only the PCWP 
rule, and not any other MACT standards.
    We feel that the final PCWP rule is particularly well-suited for a 
risk-based option because of the specific pollutants that are emitted. 
For many affected sources, the pollutants are emitted in amounts that 
pose little risk to the surrounding population. However, the cost of 
controlling these pollutants is high and may not be justified by 
environmental benefits for these low-risk facilities. Only those PCWP 
affected sources that demonstrate that they are low risk are eligible 
for inclusion in the delisted low-risk subcategory. The criteria 
defining the delisted low-risk subcategory are based on sufficient 
information to develop health-protective estimates of risk and will 
provide ample protection of human health and the environment.
    The final PCWP NESHAP is being promulgated by the February 2004 
court-ordered deadline. Any delays in implementation of the final PCWP 
NESHAP caused by legal challenges, which could and often do occur for 
any MACT standard we promulgate without a risk-based approach, are 
beyond our control.
2. Legal Authority
Section 112(d)(4) of the CAA
    Comment: We received multiple comments stating that CAA section 
112(d)(4) provides EPA with authority to exclude sources that emit 
threshold pollutants from regulation. We also received multiple 
comments disagreeing that CAA section 112(d)(4) can be interpreted to 
allow exemptions for individual sources. Several commenters supported 
the use of a CAA section 112(d)(4) applicability cutoffs for both 
threshold and non-threshold pollutants.
    Response: We feel that section 112(d)(4) does not give us the 
authority to exempt affected sources or emission points from MACT 
limitations on non-threshold pollutant emissions. All PCWP facilities 
emit carcinogens (e.g., formaldehyde), that are currently considered 
non-threshold pollutants. Therefore, we are not using section 112(d)(4) 
authority to create risk-based options for PCWP.
    We are not setting a risk-based emission limit, but, rather, we are 
using our CAA section 112(c)(9) authority to delist affected sources 
that demonstrate they meet the risk and hazard criteria for being 
included in this low-risk subcategory.

De minimis

    Comment: Some commenters attempted to identify a source of 
authority for risk-based approaches under the de minimis doctrine 
articulated by appellate courts. The commenters cited case law which 
they believe holds EPA may exempt de minimis sources of risk from MACT-
level controls because the mandate of CAA section 112 is not 
extraordinarily rigid and the exemption is consistent with the CAA's 
health-protective purpose. The commenters argued that CAA sections 
112(c)(9) and 112(f)(2) indicate that Congress considered a cancer risk 
below one in a million to be de minimis and, therefore, insufficient to 
justify regulation under section 112. The commenters stated that EPA's 
exercise of de minimis authority has withstood judicial challenge, and 
that application of de minimis authority is based on the degree of risk 
at issue, not on the mass of emissions to be regulated.
    Other commenters argued that de minimis authority does not exist to 
create MACT exemptions on a facility-by-facility or category-wide 
basis. The commenters stated that EPA lacks de minimis authority to 
delist subcategories based on risk. The commenters further noted that 
EPA has not revealed any administrative record

[[Page 45987]]

justifying a de minimis exemption, to demonstrate that compliance with 
MACT would yield a gain of trivial or no value.
    Response: We are not relying on de minimis principles for today's 
action, and therefore, do not need to respond to these comments.
Section 112(c)(9) of the CAA
    Comment: Two commenters opposed using subcategorization as a 
mechanism to exempt facilities. One of the commenters stated that 
subcategorization is a tool that should be used in the standard setting 
process, and using it to exempt facilities would have a detrimental 
effect on the stringency of the MACT floor and would generally degrade 
the standard. According to the commenter, the two-step 
subcategorization proposal is inconsistent with how subcategorization 
has been done in numerous previous NESHAP.
    The other commenter argued that EPA's subcategorization theories 
are unlawful. According to the commenter, CAA section 112(c)(9) does 
not authorize EPA to separate identical pollution sources into 
subcategories that are regulated differently to weed out low-risk 
facilities or reduce the scope/cost of the standard. The commenter 
stated that subcategories based solely on risk do not bear a reasonable 
relationship to Congress' technology-based approach or the statutory 
structure and purposes of CAA section 112, and are not authorized by 
the CAA. According to the commenter, categories and subcategories are 
required to be consistent with the categories of stationary sources in 
CAA section 111. The commenter was not aware of any instance in which 
EPA has established categories or subcategories based on risk. The 
commenter stated that EPA routinely defines subcategories based on 
equipment characteristics (e.g., technical differences in emissions 
characteristics, processes, control device applicability, or 
opportunities for P2). According to the commenter, EPA has not offered 
any explanation for why reinterpreting the statute to ignore nearly 12 
years of settled practices and expectations under the MACT program is 
reasonable, nor why reducing the applicability of HAP emission 
standards serves Congress's goals in enacting the 1990 CAA Amendments.
    The commenter noted that EPA's discussion of the risk-based 
exemptions was contained in a preamble section entitled, ``Can We 
Achieve the Goals of the Proposed Rule in a Less Costly Manner,'' which 
strongly suggests that EPA's motivation for considering these risk-
based approaches is consideration of cost. The commenter cited prior 
EPA documentation and stated that EPA in the past has rejected the 
notion that cost should influence MACT determination, and this prior, 
consistently applied interpretation better serves the purposes of CAA 
section 112. The commenter argued that subcategorizing to set a no-
control MACT floor is the same as refusing to set a MACT standard 
because the benefits would be negligible, which is unlawful.
    The commenter also stated that CAA section 112(c)(9)(B)(i) does not 
authorize EPA to delist subcategories. According to the commenter, 
section 112(c)(9)(B) contains two subsections: subsection (i) refers 
only to categories, and subsection (ii) refers to both categories and 
subcategories. The commenter argued that the absence of the term 
``subcategories'' in section 112(c)(9)(B)(i) indicates a Congressional 
choice not to permit the Administrator to delist subcategories of 
sources under section 112(c)(9)(B). The commenter stated that this is 
consistent with Congress' decision to require a higher standard to 
delist categories that emit carcinogens. According to the commenter, 
the section 112(c)(9)(B)(ii) requirement of less than one in a million 
lifetime cancer risk for the most exposed individual is a higher and 
more specific standard than the standard for other HAP.
    To the contrary, two commenters stated that EPA has ample authority 
under CAA sections 112(c)(1) and 112(c)(9) to create and delist low-
risk categories or subcategories. According to the commenters, section 
112(c)(1) provides the Administrator with significant flexibility to 
create categories and subcategories as needed to implement CAA section 
112. One commenter stated that there is nothing in the statute that 
limits the criteria the Administrator can use in establishing 
categories and subcategories. The commenter added that there is also 
nothing in the history of EPA's interpretation of section 112(c) that 
precludes subcategorization based on risk. In addition, EPA has stated 
that emission characteristics are factors to be considered when 
defining categories.
    The commenter stated that application of statutory authority to 
exclude sources from regulation under section 112(d)(3) is also 
supported by relevant case law, e.g., in the Vinyl Chloride case. (NRDC 
v. EPA, 824 F.2D 1126 (D.C. Cir. 1987)) According to the commenter, the 
court in that case established a range of acceptable levels of risk in 
establishing limits under prior language in section 112, and the 
establishment of an acceptable level of risk could be used to create a 
low-risk subcategory that could be delisted. The commenter stated that 
technological or operational differences among sources may also help 
discriminate between low-risk and high-risk sources. The commenter 
stated that effective use of section 112(c)(1) authority to create 
risk-based subcategories would significantly improve the cost-
effectiveness of the section 112 program without undermining its role 
in protecting public health and the environment.
    Both commenters noted that CAA section 112(c)(9)(B) provides EPA 
with broad authority to remove from MACT applicability those categories 
and subcategories of facilities whose HAP emissions are sufficiently 
low as to demonstrate a cancer risk less than one in a million to the 
most exposed individual in the population (for non-threshold 
carcinogens) and no adverse environmental or public health effect (for 
threshold HAP). (The commenter asserted that Congress used the terms 
category and subcategory interchangeably, indicating that either one 
can be delisted.) One commenter suggested that sources able to 
demonstrate a basis for inclusion in the delisted category on a case-
by-case basis would then be exempted from the MACT, subject to possible 
federally-enforceable conditions designed by EPA. The commenter stated 
that the new category could include the following: all low-risk 
facilities, facilities producing wood products found to pose no 
expected risk to human health (i.e., fiberboard, medium density 
fiberboard and plywood), facilities with acrolein emissions below a 
certain threshold, or facilities selected on the basis of some other 
risk criterion. The commenter suggested that the low-risk category be 
included in the final rule and delisted within 6 months following 
publication of the final rule. The delisting notices would designate 
health benchmarks and facilities would be required to submit evidence 
(e.g., tiered dispersion modeling) demonstrating that their emissions 
result in exposures that fall below the benchmarks. Following delisting 
of the category, an affected source could apply to EPA for a 
determination that it qualifies for inclusion in the low-risk category. 
After evaluating the source's petition, EPA would issue a written 
determination of applicability based on the petition that would be 
binding on the permitting authority (unless the petition was found to 
contain significant errors or omissions) and appealable by the affected 
source or interested parties.

[[Page 45988]]

The EPA could require all facilities that qualify for inclusion in the 
delisted category to comply with federally-enforceable conditions, 
similar to the conditions established in permits for synthetic minor 
sources (e.g., limits on potential to emit, production limits).
    The commenter also responded to objections regarding the 
subcategorization and delisting of low-risk facilities. The commenter 
stated that the contrasting of the terms category and subcategory 
offered a distinction that in no way limited EPA's authority to delist 
low-risk facilities. According to the commenter, the argument that EPA 
cannot create subcategories based on risk is contradicted by the 
statutory language, which expressly states that the categories and 
subcategories EPA creates under CAA section 112 need not match those 
created under CAA section 111. Furthermore, prior EPA statements do 
nothing to detract from EPA's broad discretion to establish categories 
and subcategories. The subcategorization factors previously discussed 
by EPA justify subcategorization based on risk. The authority cited by 
one commenter does not establish that EPA's discretion to alter 
subcategorization is limited in any way, and even if it were, EPA is 
not bound by any prior position. The arguments that EPA may not delist 
subcategories for carcinogens (or sources emitting carcinogens) rest on 
a formalistic distinction that EPA previously has rejected as 
meaningless, and that, at any rate, can be remedied with a simple 
recasting of a subcategory as a category. The commenter stated that 
doing so is undisputedly within EPA's authority.
    Three commenters addressed the issue of subcategorizing PCWP 
facilities based on characteristics other than risk. One commenter 
stated that the only option that appears consistent with the CAA, does 
not create excessive work for State and local agencies, and may be able 
to be based on science, is the subcategorization and delisting 
approach. However, the commenter added that the subcategories should be 
based on equipment or fuel use, not risk. The commenter stated that a 
subcategory based on site-specific risk creates a circular definition 
and does not make sense. The commenter also stated that subcategory 
delisting should occur before the compliance date so that facilities do 
not put off compliance in the hope or anticipation of delisting.
    The second commenter stated that EPA requested comment on the 
establishment of PCWP subcategories ostensibly based on physical and 
operational characteristics, but in reality based on risk. According to 
the commenter, this indirect approach is just a variation on the 
approach (direct reliance on risk) that it claims EPA itself notes 
would disrupt and weaken establishment of MACT floors, and is 
accordingly unlawful. The commenter stated that, even if these 
approaches were lawful, to the extent that EPA's proposal could be read 
to suggest that facilities could be allowed to become part of the 
allegedly low-risk subcategory in the future without additional EPA 
rulemaking, this too would be unlawful. According to the commenter, CAA 
section 112(c)(9) provides the EPA Administrator alone the authority to 
make delisting determinations, and such authority may not be delegated 
to other government authorities or private parties. The commenter 
stated that EPA's proposal suggests an approach entirely backward from 
the statute-allowing sources to demonstrate after-the-fact that they 
belong in a subcategory that has been delisted under section 112(c)(9), 
when the statute requires that EPA determine that no source in the 
category emits cancer-causing HAP above specified levels, or that no 
source in the category or subcategory emit non-carcinogenic HAP above 
specified levels, by the time EPA establishes the standard. The 
commenter stated that EPA has provided no explanation of how the 
suggested approaches would be lawful or workable.
    The third commenter indicated that low risk is an adequate and 
appropriate criterion for categorization. The commenter disagreed that 
EPA should create and delist categories on a technology basis when the 
intent is delisting of low-risk facilities. The commenter believed that 
seeking a technology-based surrogate for risk is unnecessary within the 
statutory framework. The commenter noted that the Congressional intent 
was ``to avoid regulatory costs which would be without public health 
benefit.'' (S. Rep. No. 228, 101st Cong., 1st. Sess. 175-6 (1990)) 
Nevertheless, the commenter described some technology-based criteria 
that they believed could be used to develop low-risk groups of PCWP 
facilities.
    Four commenters addressed the impact that creation of a low-risk 
subcategory under CAA section 112(c)(9) could have on the establishment 
of MACT floors for the PCWP category. Two commenters argued that such 
subcategorization would have a negative effect. One commenter stated 
that this situation provided a valid reason for EPA not to mix risk-
based and technology-based standards development. The commenter added 
that EPA also did not address how the ``once in, always in'' policy 
would apply in such a situation. The other commenter stated that this 
situation was another compelling reason why the suggested section 
112(c)(9) subcategorization approach was unlawful and arbitrary. The 
commenter stated that the flaw was so obvious, inherent, and contrary 
to the MACT floor provisions of CAA section 112 and its legislative 
history, that it proves the undoing of the suggested section 112(c)(9) 
exemption. According to the commenter, EPA cannot simultaneously 
exercise its source category delisting authority consistent with 
section 112(c)(9), establish appropriate MACT floors under CAA section 
112(d), and establish subcategory exemptions in the manner suggested by 
EPA, because the latter approach contravenes both section 112(c)(9) and 
the section 112(d) floor-setting process. The commenter stated that CAA 
section 112's major source thresholds and statutory deadlines make 
clear that sources meeting MACT by the time EPA is required to issue 
MACT standards must install MACT controls and may not subsequently 
throw them off or be relieved from meeting the MACT-level standards. 
While the CAA section 112(f) residual risk process allows EPA to 
establish more stringent emissions standards, there is nothing in the 
CAA that suggests EPA possesses authority to relax promulgated MACT 
standards.
    The third commenter indicated that dilution of the MACT floor would 
not occur if low-risk category delisting occurred as follows: (1) 
Propose low-risk category with final PCWP rule, (2) promulgate low-risk 
category 6 months after proposal, and (3) delist facilities prior to 
MACT compliance deadline. If EPA issued the final PCWP rule-thereby 
setting the MACT floor-before it allowed affected sources to apply for 
inclusion in the low-risk category to be delisted, then every affected 
source would be considered in the establishment of the MACT floor. 
Thus, as a result of this timing, the MACT floor could not be diluted 
because no sources would be exempted from MACT before the MACT floor is 
set.
    The fourth commenter believed that a MACT floor reevaluation would 
be appropriate and would further ensure that only facilities posing 
significant risk are required to install expensive controls.
    Response: We feel that establishing a low-risk PCWP subcategory 
under CAA section 112(c)(1) and deleting that subcategory under CAA 
section 112(c)(9) best balances Congress' dual

[[Page 45989]]

concerns that categories and subcategories of major sources of HAP be 
subject to technology-based (and possible future risk-based) emission 
standards, but that undue burdens not be placed on groups of sources 
within the PCWP source category whose HAP emissions are demonstrated to 
present little risk to public health and the environment. We do not 
contend that the CAA specifically directs us to establish categories 
and subcategories of HAP sources based on risk, and we recognize that, 
at the time of the 1990 CAA Amendments, Congress may have assumed that 
we would generally base categories and subcategories on the traditional 
technological, process, output, and product factors that had been 
considered under CAA section 111. However, when properly considered, it 
becomes apparent that Congress did not intend the unduly restrictive- 
and consequently over-regulatory-reading of the CAA that some 
commenters urge regarding low-risk PCWP facilities.
    Numerous CAA section 112 provisions evidence Congress' intent that 
we be able to find that sources, such as those in the PCWP category 
whose HAP emissions are below identified risk levels, should not 
necessarily be subject to MACT. These provisions, together with other 
indications of Congressional intent regarding the goals of section 112, 
must all be considered in determining whether we may base a PCWP 
subcategory on risk and delist that group of sources, without requiring 
additional HAP regulation that would be redundant for purposes of 
meeting Congress' risk-based goals.
    While it is true that CAA section 112(c)(1) provides that ``[t]o 
the extent practicable, the categories and subcategories listed under 
this subsection shall be consistent with the list of source categories 
established pursuant to section 111 and part C[,]'' the provision also 
states that ``[n]othing in the preceding sentence limits the 
Administrator's authority to establish subcategories under this 
section, as appropriate.'' Therefore, by its plain terms, section 
112(c)(1) does not preclude basing subcategories on criteria other than 
those traditionally used under section 111 before 1990, or those used 
after 1990 for sections 111 and 112. Moreover, while after 1990 we have 
principally used the traditional criteria to define categories and 
subcategories, such use in general does not restrict how we may define 
a subcategory in a specific case, ``as appropriate,'' since each HAP-
emitting industry presents its own unique situation and factors to be 
considered. (See, e.g., Sierra Club v. EPA, D.C. Cir. No. 02-1253, 2004 
U.S. App. LEXIS 348 (decided Jan. 13, 2004).)
    Even assuming for argument that the language of section 112(c)(1) 
may initially appear to restrict our authority to define subcategories, 
section 112(c)(1) cannot be read in isolation. A broad review of the 
entire text, structure, and purpose of the statute, as well as 
Congressional intent shows that, applied within the context of CAA 
section 112(c)(9), our approach of defining a low-risk subcategory of 
PCWP affected sources is reasonable, at the very least as a way to 
reconcile the possible tension between the arguably restrictive 
language of section 112(c)(1) and the Congressional intent behind 
section 112(c)(9). (See, e.g., Virginia v. Browner, 80 F.3d 869, 879 
(4th Cir. 1996).) Alternatively, even if the language is clear on its 
face in restricting our ability to define subcategories, we feel that, 
as a matter of historical fact, Congress could not have meant what the 
commenter asserts it appears to have said, and that as a matter of 
logic and statutory structure, it almost surely could not have meant 
it. (See, e.g., Engine Mfrs. Ass'n v. EPA, 88 F.3d 1075, 1089 (D.C. 
Cir. 1996).)
    Our interpretation of the CAA is a reasonable accommodation of the 
statutory language and Congressional intent regarding the relationship 
of the statutory categorization and subcategorization, delisting, MACT 
and residual risk provisions that apply to the PCWP category. This 
becomes clear in light of the issue addressed by commenters, which is 
whether we may delist a subcategory of low-risk PCWP affected sources 
only if such a group of sources is defined by criteria we have 
traditionally used to define categories and subcategories for 
regulatory, rather than delisting purposes. Our approach implements 
Congressional intent to avoid the over-regulatory result that flows 
from an overly rigid reading of the CAA. When the CAA is read as a 
whole, it is apparent that Congress-which in 1990 likely did not fully 
anticipate the policy considerations that come into play in regulating 
HAP emissions from PCWP affected sources-has not spoken clearly on the 
precise issue. Our interpretation is necessary to fill this statutory 
gap and prevent the thwarting of Congressional intent not to 
unnecessarily burden low-risk PCWP facilities by forcing them to meet 
stringent MACT controls when they already meet the risk-based goals of 
section 112. Our interpretation thus lends symmetry and coherence to 
the statutory scheme.
    While we do not feel that CAA section 112(c)(1) actually restricts 
our authority to establish a low-risk PCWP subcategory, even if the 
language is so restrictive, it must be read within the context of 
Congress' purpose in allowing us to delist categories and subcategories 
of low-risk sources that are defined according to the traditional 
criteria under CAA section 111. It is beyond dispute that Congress 
determined that certain identifiable groups or sets of sources may be 
delisted if, as a group and without a single constituent source's 
exception, they are below the enumerated eligibility criteria of CAA 
section 112(c)(9). There is no apparent reason why such a group or set 
of sources must be limited to those defined by traditional 
categorization or subcategorization criteria. This is because, first, 
Congress in section 112(c)(1) clearly did not absolutely prohibit us 
from basing categories and subcategories on other criteria generally; 
and, second, the underlying characteristic of an eligible set or group 
of sources under section 112(c)(9)-that no source in the set or group 
presents risks above the enumerated levels-can be applied under several 
approaches to defining categories and subcategories and is not 
dependent upon such set or group being traditionally defined in order 
to implement the purpose of section 112(c)(9). Put another way, there 
is nothing apparent in the statute that precludes us from delisting a 
discernible set of low-risk PCWP affected sources just because that set 
cannot also be defined according to other traditional criteria that 
have nothing to do with the question of whether each of the constituent 
PCWP affected sources is low risk. As a matter of logic and statutory 
structure, Congress almost surely could not have meant to require that 
every identifiable group of low-risk PCWP affected sources, no matter 
how large in number or in percentage with respect to higher-risk 
affected sources in the PCWP category, must remain subject to CAA 
section 112, simply because that group could not be subcategorized as 
separate from the higher risk PCWP affected sources by application of 
traditional subcategorization criteria.
    Where Congress squarely confronted the issue, it explicitly 
provided relief for categories and subcategories, defined by 
traditional criteria, that also happen to present little risk. (See CAA 
sections 112(d)(4), 112(c)(9), and 112(f)(2).) These CAA provisions 
addressing risk-based relief from, or thresholds for, HAP emissions 
regulation evidence

[[Page 45990]]

Congressional concern that the effects of such pollution be taken into 
account, where appropriate, in determining whether regulation under CAA 
section 112 is necessary. At the time of the 1990 Amendments, Congress 
did not consider it necessary to provide express relief for additional 
groups such as low-risk PCWP facilities, beyond those defined by 
traditional category and subcategory criteria, because it assumed we 
could implement a comprehensive regulatory scheme for air toxics that 
would both address situations where technology-based standards were 
needed to reduce source HAP emissions to levels closer to the risk-
based goals of section 112, and avoid unnecessary imposition of 
technology-based requirements on groups of sources that were already 
meeting those goals. Congress enacted or revised various CAA air toxics 
provisions--including sections 112(c), (d) and (f)--to that end. Had 
events unfolded in that anticipated fashion, in the case of each 
industrial category and subcategory, there would have been a perfect 
correlation between the traditional criteria for defining categories 
and subcategories and the facts showing whether those groups are either 
high-or low-risk HAP sources.
    This context turned out to be more complex than Congress 
anticipated, and in the case of PCWP facilities there is no clear 
differentiation between high-versus low-risk sources that corresponds 
to our traditional approach for identifying source categories and 
subcategories. Nevertheless, as in the case of a low-risk source group 
defined by traditional category or subcategory criteria, for the PCWP 
industry, we are able to identify a significant group of sources whose 
HAP emissions pose little risk to public health and the environment, 
applying the same section 112(c)(9) delisting criteria that would apply 
to any traditionally-defined source group. We feel it is reasonable to 
conclude that Congress would not have intended to over-regulate the 
low-risk PCWP affected sources due to the inability to define such a 
group by traditional criteria and thereby frustrate the coherent scheme 
Congress set forth of ensuring that HAP sources ultimately meet common 
risk-based goals under section 112.
    The commenter's assertion that we are inappropriately altering our 
interpretation of the applicable statutory provisions and departing 
from the traditional categorization and subcategorization criteria in 
addressing low-risk PCWP facilities is thus unfounded. As explained 
above, the complexity of the air toxics problem and the relationship 
between the traditional criteria and what might be groups of low-risk 
sources, a context not fully understood by either Congress or EPA at 
the time of the 1990 Amendments, provides adequate justification for 
any unique applications of the our approach for low-risk PCWP 
facilities.
    Our approach does not equate to one that Congress considered and 
rejected that would have allowed source-by-source exemptions from MACT 
based on individualized demonstrations that such sources are low risk. 
This is because, contrary to that approach, we rely upon the 
application of specific eligibility criteria that are defined in 
advance of any source's application to be included in the low-risk PCWP 
subcategory, in much the same way as any other applicability 
determination process works. Moreover, in response to the assertion 
that our approach nevertheless conflicts with legislative history 
rejecting a similar (but not identical) approach Congress considered 
under CAA section 112, this legislative history is not substantive 
legislative history demonstrating that Congress voted against relief 
from MACT in this situation-there is no such history. The commenters 
point to a provision in the House bill that was not enacted but that 
would have provided in certain situations for case-by-case exemptions 
for low-risk sources. There is no evidence that this provision was ever 
debated, considered, or voted upon, so its not being enacted is not 
probative of congressional intent concerning our ability to identify 
and delist a group of low-risk PCWP affected sources. Instead, it is 
reasonable to assume that, had Congress been aware in 1990 of the 
possibility that an identifiable group of PCWP affected sources is low 
risk, while that group does not correspond to traditional criteria 
differentiating categories and subcategories, Congress would have 
expressly, rather than implicitly, authorized our action here.
    Moreover, the commenters are unable to cite any provision in CAA 
section 112 that would prevent us from being able to add individual or 
additional groups of low-risk PCWP affected sources to the group we 
initially identify in our final delisting action, as those additional 
low-risk PCWP affected sources prove their eligibility for inclusion in 
the delisted group over time. In fact, the approach we are taking for 
identifying additional low-risk PCWP affected sources is fully 
consistent with the approach we have long taken in identifying, on a 
case-by-case basis and subject to appropriate review, whether 
individual sources are members of a category or subcategory subject to 
standards adopted under CAA sections 111 and 112.
    Regarding the comment that Congress did not expressly provide 
relief for carcinogen-emitting low-risk groups of sources within the 
PCWP category other than as an entire category, we construe the 
provisions of CAA section 112(c)(9) to apply to listed subcategories as 
well as to categories. This construction is logical in the context of 
the general regulatory scheme established by the statute, and it is the 
most reasonable one because section 112(c)(9)(B)(ii) expressly refers 
to subcategories. Under a literal reading of section 112(c)(9)(B), no 
subcategory could ever be delisted, notwithstanding the explicit 
reference to subcategories, since the introductory language of section 
112(c)(9)(B) provides explicit authority to only delist categories. 
Such a reading makes no sense, at the very least because Congress 
plainly assumed we might also delist another collection of sources 
besides either categories or subcategories, even in the case of sources 
of carcinogens. Both sections 112(c)(9)(B)(i) and (ii) refer 
additionally to groups of sources in the case of area sources as being 
eligible for delisting, even though only a category of sources is 
specifically identified as eligible for delisting in the introductory 
language of section 112(c)(9)(B). In light of the broader congressional 
purpose behind the delisting authority, we interpret the absence of 
explicit references to subcategories in this introductory language and 
in section 112(c)(9)(B)(i) as representing nothing more than a drafting 
error.
    Regarding the comments about establishing PCWP subcategories based 
on characteristics other than risk, the criteria for the low-risk 
subcategory we are delisting are based solely on risk and not on 
technological differences in equipment or emissions. We performed an 
analysis to determine which major source PCWP affected sources may be 
low-risk affected sources. Whether affected sources are low risk or not 
depends on the affected source HAP emissions; and affected source HAP 
emissions are a function of the type and amount of product(s) produced, 
the type of process units (e.g., direct-fired versus indirect-fired 
dryers) used to produce the product, and the emission control systems 
in place. Our analysis indicates that the affected sources which show 
low risk could include affected sources producing various products such 
as particleboard, molded particleboard, medium density fiberboard, 
softwood plywood, softwood veneer, fiberboard, engineered wood 
products, hardboard, and oriented strandboard. However, there are also 
major sources that

[[Page 45991]]

produce these products that are not low risk, and, therefore, product 
type cannot be used to define the low-risk subcategory. There is no 
correlation between production rate and low-risk affected sources 
(e.g., when affected sources are sorted by production rate for their 
product, the low-risk affected sources are not always at the lower end 
of the production rate range), so production rate cannot be used as 
criteria for defining the low-risk subcategory. The low-risk affected 
sources use a variety of process equipment (e.g., veneer dryers at 
softwood plywood plants and tube dryer at MDF plants). This same 
equipment is used at PCWP plants that are not low risk, and, therefore, 
there is no process unit type distinction that can be used to define 
the low-risk subcategory. The pollutant that drives the risk estimate 
can vary from affected source to affected source because of the 
different types of process units at each affected source. There is no 
clear distinction among low-risk and non-low-risk affected sources when 
ranked by emissions of individual pollutants because of other factors 
that contribute to affected source risk such as presence of a co-
located PCWP facility or variability in the pollutants emitted. Thus, 
there is no emissions distinction that can be used to define the low-
risk subcategory. There is no technological basis for creating a 
subcategory of PCWP affected sources that are low risk. The commonality 
between all of the low-risk PCWP affected sources is that they are low 
risk, and, therefore, we have established the low-risk subcategory 
based on risk.
    We do not agree with the commenters' assertions that our approach 
for the low-risk PCWP subcategory undermines our ability to identify 
the MACT floor for the larger PCWP category, either in today's final 
PCWP rule or in any future consideration of technological development 
under CAA section 112(d)(6). This is because, while low-risk PCWP 
affected sources will literally be part of a separate subcategory, 
there is nothing in the CAA that prevents us from including them in any 
consideration of what represents the best controlled similar source in 
the new source MACT floor context, and because it is not unprecedented 
for us to look outside the relevant category or subcategory in 
identifying the average emission limitation achieved by the best 
controlled existing sources if doing so enables us to best estimate 
what the relevant existing sources have achieved. In fact, EPA has 
taken this very approach in the Industrial Boilers MACT rulemaking, in 
order to identify the MACT floor for mercury emissions. Moreover, the 
unique issues presented by the low-risk PCWP subcategory show that it 
would be unreasonable to exclude any better-performing low-risk PCWP 
sources from the MACT floor pool for the larger PCWP category. 
Traditionally, EPA has based categories and subcategories partly on 
determinations of what pollution control measures can be applied to the 
relevant groups of sources in order to effectively and achievably 
reduce HAP. In other words, EPA has identified subcategories for 
purposes of identifying the MACT floor in a way that accounts for the 
differences of sources types in their abilities to control HAP 
emissions. But whether a PCWP source is a low-risk source does not 
necessarily turn on such a distinction--two sources might have 
identical abilities to control HAP emissions, but the unique 
circumstances of one source regarding the impacts of its HAP emissions 
will determine whether or not it is a low-risk PCWP source. (In fact, 
it is theoretically possible that between two sources the better 
performing source will be a high-risk source, and the worse-performing 
source will be a low-risk source, based on circumstances that are 
unrelated to the question of what abilities the sources have to control 
HAP emissions through application of MACT, such as the sources' 
locations vis a vis exposed human populations.) Therefore, EPA feels 
that not only is it appropriate to include any better-performing low 
risk PCWP sources in the MACT floor determinations for the larger PCWP 
category, but that excluding such sources simply based on the unique 
facts of the impacts of their emissions, with there being no difference 
in the abilities of high-risk and low-risk sources to apply HAP 
emission control measures, could result in an undesirable weakening of 
the MACT floor for the larger PCWP category. To that end, the MACT 
floors established for PCWP process units today are in no way affected 
by our establishment of the low-risk PCWP subcategory.
    Finally, we disagree with the argument by one commenter that the 
low-risk PCWP subcategory approach represents an impermissible cost-
based exemption from MACT or factor in determining MACT. Certainly it 
is true that costs may not be considered in setting the MACT floor. 
However, there is nothing in the CAA that prevents us from noting the 
cost impacts, beneficial or adverse, of our actions in setting MACT 
floors, assessing possible beyond-the-floor measures, or conducting 
risk-based actions under CAA section 112. In fact, we routinely 
evaluate the costs of our regulatory actions, even when cost factors 
may not be used to influence the regulatory decision itself, in order 
to comply with applicable Executive Order and statutory administrative 
review requirements. Simply because there is a cost benefit to some 
members of the PCWP category in our establishing a low-risk PCWP 
subcategory does not make that action impermissible, provided that our 
subcategorization and delisting are otherwise properly based on the 
appropriate risk-based criteria under CAA section 112(c)(9). Section 
112 by its own terms does not forbid the goal of achieving 
environmental protection in a less costly manner. Similarly, it is 
appropriate for EPA to note the beneficial air pollution-related 
impacts of not requiring low-risk PCWP sources to, for example, install 
criteria pollutant emission-producing RTOs. While it is true that such 
air quality-related impacts could not constitute non-air quality health 
and environmental impacts that EPA must consider when setting MACT 
under CAA section 112(d)(2), nothing in the CAA prevents EPA from 
taking account of such impacts in developing its policy regarding 
whether it is appropriate to delist a subcategory under section 
112(c)(9) when that subcategory otherwise meets the statutory criteria 
for delisting. Therefore, EPA does not agree with commenters who claim 
that its approach to delisting the low risk PCWP subcategory conflicts 
with how it has argued issues regarding either de minimis authority, 
cost-based exemptions from MACT, or the treatment of non-air quality 
impacts and the consideration of risk in setting the actual MACT 
standard before the U.S. Court of Appeals for the D.C. Circuit. Nor 
does our approach contravene any of that Court's rulings on these 
issues.
3. Criteria for Demonstrating Low Risk Dose-response Values
    Comment: Two commenters suggested that EPA incorporate into the 
PCWP rule the findings of the nationwide wood products risk assessment, 
which they claim demonstrates that the vast majority of wood products 
sources cause no meaningful risk to human health or the environment at 
current emission levels. The commenters stated that the risk assessment 
used existing air dispersion modeling studies of 34 wood products 
facilities throughout the U.S. to estimate the maximum annual off-site 
HAP concentrations at wood products facilities nationwide. According to 
the commenters, the risk assessment indicates that large

[[Page 45992]]

subgroups of facilities that are affected sources under the PCWP rule 
as proposed (i.e., fiberboard, medium density fiberboard, and plywood 
facilities) generally are expected to pose insignificant risks to human 
health, based on a comparison of predicted off-site concentrations with 
applicable health benchmarks. One of the commenters stated that many of 
the facilities with low off-site concentrations will likely be smaller 
plants that would not be able to justify installation of (additional) 
emission controls and may face closure without a risk-based compliance 
option. The other commenter stated that a comparison of off-site 
concentrations of formaldehyde and acetaldehyde with benchmarks 
reflecting the latest toxicological evidence indicates that exposures 
to those HAP are well below levels of concern. Acrolein was the only 
HAP with potential exposures at some affected sources (i.e., subset of 
fiberboard, medium density fiberboard and plywood affected sources) 
that exceeded the health benchmark. However, the commenter stated that 
the acrolein findings may not represent an actual risk to human health 
because exceedences of the benchmark may be attributable to EPA 
averaging a large number of non-detects at one-half the detection 
limit, thereby artificially increasing predicted acrolein emissions. 
Based on these overall findings, the commenter concluded that the wood 
products risk assessment indicates that incinerator control is not 
warranted on the basis of human health concerns for a large number of 
facilities.
    Response: We acknowledge receipt of the industry-sponsored 
nationwide wood products MACT risk assessment submitted by the 
commenter. However, we conducted our own risk analysis to evaluate the 
merits of including and delisting a low-risk subcategory in today's 
final PCWP rule. The methodology used in our risk analysis differed 
widely from the methodology used in industry's risk assessment. For 
example, industry's risk assessment was based on previously conducted 
air dispersion modeling studies for 34 PCWP facilities, while our 
analysis used emission estimates developed for each PCWP affected 
source expected to be a major source of HAP. We used different 
(generally more protective) human health benchmarks in our risk 
assessment than were used in industry's risk assessment. We also 
considered all HAP (including metal HAP) in our risk analysis, whereas 
industry's risk assessment considered only methanol, formaldehyde, 
acetaldehyde, acrolein, phenol, and propionaldehyde.
    Based on our risk analysis, we conclude that HAP emissions from 
some PCWP affected sources pose little risk to human health and the 
environment. Therefore, we have included a subcategory of low-risk PCWP 
affected sources in today's final PCWP rule, and are delisting that 
subcategory. Appendix B to subpart DDDD of 40 CFR part 63 includes 
procedures that facilities may use to demonstrate that they are part of 
the delisted low-risk subcategory, and, therefore, are not subject to 
the compliance options included in today's final PCWP MACT rule. To 
demonstrate eligibility for the low-risk subcategory, facilities must 
first conduct emissions testing for up to 13 HAP (five organic HAP from 
all process units, seven metal HAP from direct-fired process units, and 
MDI from presses processing product containing MDI resin). The 
rationale for selection of these 13 HAP is described elsewhere in this 
section and in the supporting documentation for the final rule. 
Facilities must use the results from emissions testing to preliminarily 
demonstrate, subject to EPA approval, that they are part of the low-
risk subcategory using either a look-up table analysis (based on the 
look-up tables included in appendix B to subpart DDDD of 40 CFR part 
63) or site-specific risk assessment methodology (described in appendix 
B to subpart DDDD of 40 CFR part 63 and other analytical tools, such as 
the ``Air Toxics Risk Assessment Reference Library'' if appropriate for 
the specific source) and risk benchmarks (described in appendix B to 
subpart DDDD of 40 CFR part 63).
    Regarding acrolein, the commenter is correct in that, when 
developing AP-42 emission factors, we used a value of one-half the 
detection limit for all non-detect sample runs if acrolein was detected 
in any sample runs from the applicable source category. Acrolein has 
been detected in process unit emissions from all sectors of the PCWP 
industry, except for hardwood plywood manufacturing. When using 
emission factors to estimate emissions from PCWP facilities, we did not 
estimate emissions of a pollutant when all of the emissions test runs 
were non-detect. However, we did use emission factors that included a 
mixture of detectable values and values based on one-half of the method 
detection limit (MDL) when acrolein was detected at least once for a 
particular type of process unit. We maintain that this approach to 
handling non-detects is appropriate for the purposes that we used the 
emissions data. Facilities will conduct emissions tests instead of 
using emission factors to demonstrate eligibility for the low-risk 
subcategory. To prevent facilities from including HAP that are not 
detected in their low-risk demonstrations, appendix B to subpart DDDD 
of 40 CFR part 63 states that facilities may use zero for non-detects 
when all of the emission test runs are below the MDL, provided that 
certain criteria are met to ensure that emissions testing and analysis 
procedures are adequate to detect low concentrations of HAP.
    Comment: One commenter stated that CAA section 112(d)(4) is 
particularly ill-suited to the PCWP and industrial boiler source 
categories. The commenter stated that, even if EPA had authority to 
create individualized MACT exemptions based on health thresholds, it 
could not do so if there is insufficient evidence on the pollutants 
emitted to establish a NOEL. According to the commenter, section 
112(d)(4) does not apply for chemicals that do not have a well-defined 
threshold based on reliable science. The commenter stated that 
available evidence does not establish a no-effect threshold for 
acetaldehyde, acrolein, benzene, carbon tetrachloride, chloroform, 
formaldehyde, manganese, methylene chloride, and phenol. As rationale, 
the commenter presented a summary of the available health effects data 
for each of these pollutants.
    Response: As stated elsewhere in this preamble, we are not pursuing 
establishment of a threshold emission rate for the PCWP source category 
under CAA section 112(d)(4) because PCWP affected sources emit non-
threshold pollutants. Therefore, this comment is irrelevant in the 
context of the PCWP rule. Comments pertaining to the Industrial/
Commercial/Institutional Boilers and Process Heaters NESHAP are 
addressed in the comment-response document for that rule. (See Docket 
ID No. OAR-2002-0058.)
    Comment: Two commenters expressed concern about the health 
benchmark data sources that EPA used. The first commenter argued that 
the proposal inappropriately used draft guidelines and toxicity 
profiles that had not been subject to public review and/or were not 
publicly available. The commenter was particularly concerned with the 
use of non-linear carcinogenic risk values and toxicity profiles (for 
HAP) that have not been finalized and are not available for review by 
the public.
    The second commenter argued that EPA should not rely solely on the 
health benchmarks in its Integrated Risk Information System (IRIS) 
database. The commenter stated that IRIS, while useful for obtaining 
information about the health effects of chemicals, is far

[[Page 45993]]

from definitive, as EPA resource constraints have resulted in many 
chemical summaries that are significantly outdated and do not reflect 
the most recent scientific developments. Moreover, the commenter stated 
that the IRIS database is a non-statutory, in-house EPA activity, and 
IRIS entries are not subject to formal notice and comment. The 
commenter noted that EPA management has repeatedly emphasized in 
directives that other information must be considered, in addition to 
the IRIS database, when evaluating the health effects of chemicals in a 
regulatory context. The commenter concluded that EPA must use a 
scientifically appropriate health benchmark based on a consideration of 
all relevant information to ensure that the health benchmark is up-to-
date and scientifically credible, even if that means departing from the 
value in IRIS.
    A third commenter agreed with EPA's choice to derive their data 
from IRIS, California EPA (CalEPA), and Agency for Toxic Substances and 
Disease Registry (ATSDR) for its documentation for establishing risk 
based threshold and non-threshold values. The commenter added that 
almost all HAP are being reviewed and reevaluated on a regular basis, 
and it would be inappropriate to single out formaldehyde and 
acetaldehyde at this time. The commenter stated that EPA can only rely 
on what is currently published and has undergone either peer review or 
EPA review. According to the commenter, the issue of changing health-
based guideline values will always be a concern once health-based 
regulations are promulgated.
    Response: We agree with the first two commenters that we should use 
the best available sources of health effects information for risk or 
hazard determinations. As we have stated previously, we will not be 
relying exclusively on IRIS values, but will be considering all 
credible and readily available assessments.\1\ 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 
internal and external peer review steps and represent EPA consensus 
values. When adequate toxicity information is not available in IRIS, we 
consult other sources in a default hierarchy that recognizes the 
desirability of these qualities in ensuring that we have consistent and 
scientifically sound assessments. Furthermore, where the IRIS 
assessment substantially lags the current scientific knowledge, we have 
committed to consider alternative credible and readily available 
assessments. For our use, these alternatives need to be grounded in 
publicly available, peer-reviewed information. Formaldehyde is an 
example of this situation. We are not using information that does not 
meet these requirements. We also agree with the third 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. Facilities conducting low-risk 
demonstrations should refer to appendix B to subpart DDDD of 40 CFR 
part 63 and other analytical tools, such as the ``Air Toxics Risk 
Assessment Guidance Reference Library'' (if appropriate for the 
specific source) for guidance on choosing appropriate dose-response 
values.
---------------------------------------------------------------------------

    \1\ 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: With the support of several others, one commenter pointed 
out that the science with respect to formaldehyde and acetaldehyde has 
changed since EPA's initial IRIS entries for those pollutants were 
completed. Consequently, the commenter believed it would be 
inappropriate for EPA to rely on the unit risk factors for those 
pollutants in the IRIS database in establishing a property line 
concentration threshold in the PCWP rule as proposed. The commenter 
supported EPA's efforts in revising its formaldehyde and acetaldehyde 
IRIS assessment and noted that both revisions are expected to be 
finalized before the final PCWP rule is published in 2004. Regarding 
formaldehyde, the commenter noted that EPA plans on using the model 
from the Chemical Industry Institute of Technology (CIIT) to revise its 
formaldehyde IRIS assessment and encouraged this action. The commenter 
pointed out that the CIIT model has been recognized by several 
authoritative bodies (e.g., Health Canada/Environment Canada, 
Organization for Economic Coordination and Development, and World 
Health Organization) as providing the most scientifically defensible 
analysis of formaldehyde. (Another commenter added that the IRIS risk 
criteria for formaldehyde clearly cause formaldehyde risk estimates to 
be overstated but argued that, even using the very conservative IRIS 
numbers, risks are still low. A third commenter urged EPA not to use 
the formaldehyde values in ATSDR, stating that they are fundamentally 
flawed, as detailed in their comment.) Regarding acetaldehyde, the 
commenter recommended that EPA use a health benchmark between 27 and 
390 micrograms per cubic meter ([mu]g/m3) and included their 
rationale in an attachment to their comment. If EPA is unable to 
complete its reassessments before the PCWP rule is finalized, the 
commenter encouraged EPA not to revert to the original IRIS unit risk 
factors for formaldehyde and acetaldehyde. Instead, the commenter 
recommended that EPA use the CIIT model (or alternatively defer to 
Health Canada/Environment Canada) for formaldehyde and, at a minimum, 
use the IRIS reference concentration (RfC) of 9 [mu]g/m3 for 
acetaldehyde.
    Response: With the exception of formaldehyde, we are using the 
human health values currently used by EPA's air toxics program and 
available at: http://www.epa.gov/ttn/atw/toxsource/summary.html. These 
dose response values come from several sources including EPA's IRIS, 
the Centers for Disease Control's ATSDR, and California EPA. See the 
supporting information for this rulemaking for a summary of the human 
health values we used in our assessment.
    For formaldehyde, we do not use the dose-response value reported in 
IRIS. The dose-response value in IRIS is based on a 1987 study, and no 
longer represents the best available science in the peer-reviewed 
literature. Since that time, significant new data and analysis have 
become available. We based the dose-response value we used for 
formaldehyde on work conducted by the CIIT Centers for Health Research 
(formerly, the Chemical Industry Institute of Toxicology). In 1999, the 
CIIT published a risk assessment which incorporated mechanistic and 
dosimetric information on formaldehyde that had been accumulated over 
the past decade. The risk assessment analyzed carcinogenic risk from 
inhaled formaldehyde using approaches that are consistent with EPA's 
draft guidelines for carcinogenic risk assessment. The CIIT model is 
based on computational fluid dynamics (CFD) models of airflow and 
formaldehyde delivery to the relevant parts of the rat and human 
respiratory tract, which are then coupled to a biologically-motivated 
two-staged clonal growth model that allows for incorporation of 
different biological

[[Page 45994]]

effects. These biological effects, such as interaction with DNA and 
cell proliferation, are processes by which formaldehyde may contribute 
to development of cancer at sites exposed at the portal of entry (e.g., 
respiratory tract). The two-staged model is a much more advanced 
approach for examining the relevance of tumors seen in animal models 
for human populations.
    We believe that the CIIT modeling effort represents the best 
available application of the available mechanistic and dosimetric 
science on the dose-response for portal of entry cancers due to 
formaldehyde exposures. We note here that other organizations, 
including Health Canada, have adopted this approach. Accordingly, we 
have used risk estimates based on the CIIT airflow model coupled to a 
two-staged clonal growth model as the basis for the dose-response 
values for this analysis. This model incorporates state-of-the-art 
analyses for species-specific dosimetry, and encompasses more of the 
available biological data than any other currently available model. As 
with any model, uncertainties exist, and this model is sensitive to the 
inputs, but we believe it represents the best available approach for 
assessing the risk of portal-of-entry cancers due to formaldehyde 
exposures.
    Currently, the CIIT information and other recent information, 
including recently published epidemiological studies, are being 
reviewed and considered in the reassessment of our formaldehyde unit 
risk estimate (URE). We plan to bring this reassessment to the Science 
Advisory Board in the summer of 2004. The feasibility of delisting a 
subgroup of affected sources based on risk is not compromised by the 
existing formaldehyde dose-response value because some affected sources 
would qualify for delisting based on this current value. We are moving 
forward with the final PCWP rule at this time because there is a court-
ordered deadline, and we are including the low-risk PCWP subcategory 
delisting and basing our review of sources's eligibility on the CIIT 
model for formaldehyde. We disagree with the statement by one of the 
commenters that risks are still low using the current IRIS number for 
formaldehyde. Our analysis has demonstrated that not all PCWP affected 
sources can be considered low risk when either the current IRIS or CIIT 
URE for formaldehyde is employed.
    While we recognize the similarities between acetaldehyde and 
formaldehyde with regard to suggested modes of action, the reassessment 
of acetaldehyde is lagging behind that of formaldehyde. The 
formaldehyde reassessment is further along because of the preponderance 
of data specific to formaldehyde and the potentially greater impact of 
a change in potency to our regulatory decisions. Unlike for 
formaldehyde, an alternative, peer-reviewed, publicly available 
assessment does not currently exist for acetaldehyde, leaving us with 
the current IRIS assessment. We do not feel it is necessary to wait for 
our acetaldehyde reassessment to be completed, due to the court-ordered 
deadline for the final PCWP MACT rule, and due to the fact that until 
otherwise concluded the IRIS values for acetaldehyde reflect the best 
available source of health effects information. Therefore, we are 
relying on the IRIS values for acetaldehyde in both cancer and non-
cancer risk assessments for the final rule.
    Affected sources conducting low-risk demonstrations should refer to 
appendix B to subpart DDDD of 40 CFR part 63 and other analytical 
tools, such as the ``Air Toxics Risk Assessment Reference Library'' (if 
appropriate for the specific source) for guidance on choosing 
appropriate dose-response values.
    Comment: One commenter stated that EPA should consider formaldehyde 
and acetaldehyde as carcinogens unless a reassessment classifies them 
as threshold pollutants. A second commenter argued that formaldehyde 
and acetaldehyde are properly treated as threshold pollutants. This 
commenter contended that the legislative history of the CAA makes clear 
that Congress considered ``threshold pollutants'' to be those for which 
a ``no observed effect level'' can be established. (See, e.g., S. Rep. 
No. 228, 101st Cong., 1st Sess. 175-176 (1990)). By contrast, a non-
threshold pollutant is one for which a no observed effect level cannot 
be identified, i.e., a pollutant for which adverse effects may be seen 
at any dose level above zero. The commenter noted that EPA has 
historically assumed that all carcinogens are non-threshold pollutants 
that may trigger a carcinogenic effect at any exposure level, no matter 
how small. However, as mechanistic data on the mode of action of 
carcinogenesis advances, that conservative assumption may prove not to 
be accurate for certain pollutants. The commenter stated that the 
available science strongly suggest that these pollutants act as 
threshold carcinogens. The commenter contended that there is a no 
observed effect level for formaldehyde below which the carcinogenic 
risk either does not exist or cannot be measured, as documented in an 
attachment to their comment. The commenter stated that acetaldehyde 
should be viewed similarly because acetaldehyde is similar to 
formaldehyde structurally and toxicologically, and is expected to 
behave similarly mechanistically. Because acetaldehyde is a less potent 
carcinogen than formaldehyde (by an order of magnitude), non-cancer 
health effects (which clearly are threshold health effects) are the 
likely risk driver for that pollutant. Finally, the commenter noted 
that EPA's recently issued Draft Final Guidelines for Carcinogenic Risk 
Assessment provide that, for non-linear carcinogens, EPA will calculate 
a reference dose (RfD) or RfC, which are safe lifetime doses (i.e., 
doses below which adverse effects will not occur). The commenter stated 
that this is exactly what a threshold pollutant is. Thus, EPA's revised 
guidelines support the conclusion that formaldehyde and acetaldehyde 
should be treated as threshold pollutants.
    Response: We agree that we should consider formaldehyde and 
acetaldehyde as carcinogens unless a reassessment classifies them as 
threshold pollutants. Currently, formaldehyde and acetaldehyde are 
considered probable human carcinogens. Both are under review, and their 
dose-response values for carcinogenicity are likely to change. For the 
final rule, we are using an alternative dose-response value for 
formaldehyde based on a peer-reviewed, publicly available assessment. 
However, we do not have comparable quantitative information for 
acetaldehyde. Therefore, we will use the current IRIS value. Affected 
sources conducting low-risk demonstrations should refer to appendix B 
to subpart DDDD of 40 CFR part 63 (and/or the ``Air Toxics Risk 
Assessment Reference Library'') for guidance on choosing appropriate 
dose-response values.
    Comment: One commenter expressed concern about some of the health 
benchmarks that EPA plans to publish. The commenter reviewed various 
health studies for each pollutant and recommended several RfC values. 
The commenter noted that, because IRIS does not have an RfC for 
methanol, EPA has indicated it plans to determine a de minimis 
threshold for methanol using a value of 4.0 milligrams per cubic meter 
(mg/m3) as an RfC. The commenter noted that this value is 
the noncancer chronic reference exposure level (REL) derived by CalEPA. 
The commenter stated that CalEPA's derivation of that REL contains some 
errors and inaccurate assumptions. According to the commenter, a more 
accurate estimate of a human safe level for chronic exposure to 
methanol by

[[Page 45995]]

inhalation, derived from the same mouse study data, is 171 mg/
m3, which is discussed further in their comments. The 
commenter stated that their discussion presents new analyses not 
previously reviewed by EPA and a ground-breaking new approach to a 
hazard assessment for methanol. The commenter noted that EPA is 
currently revising its assessment for acrolein and has provided for 
public information a draft toxicological review and draft IRIS summary 
for acrolein. The draft IRIS document states that the proposed new RfC 
of 0.03 [mu]g/m3 replaces the previous RfC of 0.02 [mu]g/
m3, and that this new RfC is based on a more recent 
interpretation of the database. The commenter noted the basis for the 
revised acrolein RfC (Feron et al., 1978) and argued that EPA's 
interpretation of this study is overly conservative. The commenter 
stated that EPA has used the maximum uncertainty factors that could 
reasonably be justifiable and thereby developed an RfC that almost 
certainly goes beyond what is needed to protect human health. The 
commenter suggested that EPA should instead use the more realistic 
reference exposure level developed by CalEPA, which is more 
conservative than the Health Canada Tolerable Concentration.
    The commenter noted that EPA has not published a health benchmark 
for phenol. The commenter agreed with EPA's proposal to use the CalEPA 
REL of 200 [mu]g/m3 for phenol in implementing the risk-
based approach for wood products facilities. According to the 
commenter, the REL is intended to serve the same goal as an RfC.
    The commenter supported using a health benchmark of 110 [mu]g/
m3 for propionaldehyde and believed that this value would 
protect human health with an ample margin of safety. The commenter 
described how the 110 [mu]g/m3 value was derived based on 
the threshold limit value (TLV) for propionaldehyde identified by the 
American Conference of Governmental Industrial Hygienists (ACGIH). The 
commenter explained that this benchmark is consistent with values 
developed by other organizations.
    Response: We are currently developing an IRIS assessment for 
methanol, and any new information that exists that has undergone peer 
review will be considered in this re-evaluation. We publish yearly in 
the Federal Register a list of all chemicals for which we are planning 
IRIS assessment activity. This action further requests submission of 
pertinent data for these chemicals. In lieu of the pending IRIS 
assessment, we will continue to draw on other sources identified by our 
established default hierarchy of data sources, which have as part of 
their development processes external or peer review, in addition to 
extensive internal reviews.
    A reassessment of acrolein was completed in June of 2003. The RfC 
resulting from that reassessment (i.e., an RfC of 0.02 [mu]g/
m3, with an uncertainty factor of 1,000) is what is 
currently on IRIS. As with all announced IRIS reassessments, time was 
provided for new data or relevant information to be submitted. In 
addition, each assessment undergoes extensive internal review as well 
as external peer review to ensure that the data used are scientifically 
sound. We feel that we have developed the most scientifically sound RfC 
that will ensure that risk assessments using this number are health-
protective. Facilities conducting low-risk demonstrations should refer 
to appendix B to subpart DDDD of 40 CFR part 63 (and/or the ``Air 
Toxics Risk Assessment Reference Library'') for guidance on choosing 
appropriate dose-response values.
    We do not currently have plans to develop an IRIS assessment for 
phenol. We will continue to rely on our hierarchy of other sources when 
IRIS values are not available.
    We do not have an IRIS file for propionaldehyde, and an assessment 
is not available from the alternative sources in our default hierarchy. 
The hierarchy sources do not include ACGIH, as that organization 
develops reference values for use in occupational exposure settings, as 
opposed to the ambient air exposures that are the focus of this action. 
Development of an IRIS assessment for propionaldehyde is currently 
underway. Once available, it will be used in future risk analyses. In 
the meantime, this HAP was not included in the assessment conducted for 
PCWP affected sources.
    Comment: One commenter stated that comparison of modeled exposures 
to the RfC or similarly-derived health benchmark is highly protective 
and meets the CAA's ``ample margin of safety'' requirement. Although 
the commenter claims the CAA does not explicitly define ``ample margin 
of safety,'' in the Vinyl Chloride case, the D.C. Circuit Court of 
Appeals articulated the purpose of the ample margin of safety 
determination as obtaining a ``reasonable degree of protection'' in 
light of scientific uncertainties and information gaps. (Natural Res. 
Def. Council v. EPA, 824 F.2D 1146, 1152-53 (D.C. Cir. 1987)). The 
commenter stated that, in regulatory practice, the ample margin of 
safety analysis consists of a consideration of the NOEL for a pollutant 
and the subsequent application of factors to account for scientific 
uncertainty surrounding that safe level of exposure. According to the 
commenter, this is the approach called for by the Senate Report 
accompanying the 1990 CAA Amendments (S. Rep. No. 228, 101st Cong. 
Sess. 171 (1990)), and this is exactly what is done in deriving an RfC 
or similar inhalation health benchmark. The commenter stated that EPA's 
derivation of the RfC contains multiple layers of conservatism to 
account for scientific uncertainty. The commenter believed that RfC 
values and similar inhalation health benchmarks already incorporate 
sufficient uncertainty factors to fulfill or exceed the ample margin of 
safety mandate of CAA sections 112(d)(4) and 112(c)(9).
    Response: Today's final PCWP rule will utilize CAA section 
112(c)(9) rather than CAA section 112(d)(4). We agree that the CAA does 
not define ``ample margin of safety'' explicitly. The CAA does, 
however, in section 112(f) explicitly recognize our Federal Register 
notice of September 14, 1989, which described our interpretation of 
ample margin of safety in the case of linear carcinogens, and our 
approach to implementing that interpretation. While the first step 
identifies the presumptive limit on maximum individual risk, the second 
step of that 2-step approach describes the setting of the risk-based 
standard at a level that provides an ample margin of safety, in 
consideration of a number of factors. As we noted in the 1989 notice, 
the objective in protecting public health with an ample margin of 
safety under CAA section 112 is to ensure an individual lifetime risk 
level no higher than one in a million to the greatest number of persons 
possible, and to limit to no higher than one in ten thousand the 
estimated risk for a person living near a plant if they were exposed 
for 70 years.
    In assessing risk or hazard of nonlinear effects, we use the RfC or 
comparable value. This value represents 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 non-cancer 
effects during a lifetime. The RfC values and comparable values are 
derived from assessments of pertinent toxicological information to 
identify the lowest point of departure (in human equivalent terms) from 
the experimental data that is also representative of the threshold 
region (the region where toxicity is apparent from the available data) 
for the array of toxicity data for that chemical. The objective is to 
select

[[Page 45996]]

a prominent toxic effect that is pertinent to the chemical's key 
mechanism or mode of action. This approach is based, in part, on the 
assumption that if the critical toxic effect is prevented, then all 
toxic effects are prevented. The RfC is derived from the point of 
departure (POD) (in terms of human equivalent exposure) for the 
critical effect by consistent application of uncertainty factors, which 
are to account for recognized uncertainties in the extrapolations from 
the experimental data conditions to an estimate appropriate to the 
assumed human scenario.\2\
    In considering the extrapolation of the ample margin of safety 
objective described for linear cancer risk to the management of risk 
for nonlinear effects under CAA section 112(c)(9) (i.e., in decisions 
to delist a subcategory from any further regulatory action), we 
consider exposures relative to the RfC or comparable values for all of 
the emitted HAP, with specific attention to those affecting a similar 
physiological target organ or system.
---------------------------------------------------------------------------

    \2\ U.S. Environmental Protection Agency. 1994. Methods for 
Derivation of Inhalation Reference Concentrations and Application of 
Inhalation Dosimetry. Office of Research and Development. EPA/600/8-
90/066F. (EPA 1994)
---------------------------------------------------------------------------

    Comment: One commenter stated that the uncertainty factors used in 
deriving the wood products HAP health benchmarks are particularly 
large. The unit risk factors for acetaldehyde and formaldehyde were 
calculated using the linear multi-stage model, which assumes a linear 
relationship between cancer incidence and exposure to the pollutant at 
low doses. According to the commenter, the available data on 
acetaldehyde and formaldehyde strongly suggest that this assumption is 
incorrect and overly conservative.
    The commenter pointed out that EPA's health assessment of acrolein 
is two to three times more conservative than CalEPA's, even though both 
are intended to protect sensitive individuals from any adverse effects 
following a lifetime of exposure. The commenter stated that EPA has 
developed an extremely conservative RfC for acrolein. The commenter 
argued that adopting a HI of 0.2 would add another five-fold safety 
factor to this already extremely conservative RfC. The commenter noted 
that acrolein is the HAP of greatest importance in determining risk 
from PCWP facilities.
    Response: The dose-response values used to determine the criteria 
for defining the low-risk subcategory are drawn from IRIS, as well as 
from certain alternative sources. The IRIS process contains internal 
and external peer review steps and represents EPA consensus values. 
When adequate toxicity information is not available in IRIS, we consult 
other sources in a default hierarchy that recognizes the desirability 
of these qualities in ensuring that we have consistent and 
scientifically sound assessments. In the case of acrolein, specifically 
mentioned by the commenter, consultation of other sources was not 
necessary because the acrolein assessment was completed within the past 
9 months and represents current scientific knowledge. In those cases 
(e.g., formaldehyde), where the IRIS assessment substantially lags the 
current scientific knowledge, we consider alternative credible and 
readily available assessments. As pointed out elsewhere in this 
section, the RfC values or comparable values have been derived with the 
incorporation of uncertainty factors. The uncertainty factors are to 
account for recognized uncertainties in the extrapolations from the 
experimental data conditions pertaining to the chemical's particular 
toxicological data set to an estimate appropriate to the assumed human 
scenario.\3\ The size variation of the uncertainty factors across RfC 
values reflects the size variation of the uncertainties associated with 
that extrapolation.
---------------------------------------------------------------------------

    \3\ Ibid.
---------------------------------------------------------------------------

    Comment: One commenter stated that the combination of conservative 
air dispersion modeling techniques and a conservative human health 
benchmark ensure that, where a source meets the requirements for a 
risk-based compliance option, human health will be protected with an 
ample margin of safety. The commenter pointed out that, for most 
individuals in the general population, actual exposures likely are one 
or more orders of magnitude below the maximum exposures predicted by 
the tiered modeling approach. The commenter noted that EPA's tiered 
modeling methodology is designed to identify the highest annual 
property line or off-site concentrations that might occur around each 
facility (as opposed to actual population exposure). The tiered 
approach models exposures of a maximally exposed individual (MEI) and 
incorporates a number of conservative assumptions. According to the 
commenter, actual average concentrations are likely to be much lower. 
The commenter argued that, even if the modeled concentrations were 
reflective of continuous average concentrations, it is highly unlikely 
that any individual would actually be exposed to such concentrations 
for a lifetime. The commenter noted that the Presidential/Congressional 
Commission on Risk Assessment and Risk Management concluded that the 
conservatism inherent in use of the MEI was often so unrealistic that 
its use impaired the scientific credibility of health risk assessment.
    Response: We discussed a tiered analytical approach in the preamble 
to the proposed rule, beginning with relatively simple lookup tables 
and followed by increasingly more site-specific but more resource 
intensive tiers of analysis, with each tier being more refined. In 
today's final rule, we are setting forth two options, as specified in 
Appendix B to subpart DDDD. In the first option, affected sources can 
qualify for inclusion in the delisted subcategory by using site-
specific emissions test data and look-up tables that were developed 
using health-protective input parameters. As a second option, affected 
sources may choose to use a more refined site-specific risk assessment. 
A more refined analysis requires more effort, but produces results that 
are less likely to overestimate risk.
    Comment: One commenter noted that the regulatory requirements in 
the proposed rule focused on six HAP that are emitted from PCWP 
facilities: acrolein, acetaldehyde, formaldehyde, methanol, phenol, and 
propionaldehyde. Those HAP represent 96 percent of the emissions from 
PCWP affected sources. The commenter believes that any risk-based 
compliance mechanisms may reasonably be limited to consideration of the 
risks from these six HAP. The commenter noted that EPA's preliminary 
risk analysis conducted prior to proposal narrowed the list of HAP 
emitted from PCWP affected sources to include the following: acrolein, 
acetaldehyde, formaldehyde, methanol, phenol, benzene, methylene 
chloride, and manganese. The commenter referred to the results of their 
sensitivity analysis, which was conducted based on the data used in 
EPA's pre-proposal risk analysis. The analysis evaluated the impact of 
increasing or decreasing facility emissions by 30 percent, using 
different health benchmarks than those identified in EPA's analysis, 
and conducting the risk assessment with the six HAP targeted in the 
proposed rule versus the additional HAP identified by EPA. The 
commenter's sensitivity analysis showed that formaldehyde and 
acetaldehyde made up the bulk of the cancer risk, while benzene and 
methylene chloride had little or no influence on cancer risk, depending 
on the scenario considered. Under all scenarios, acrolein contributed 
the most

[[Page 45997]]

non-cancer risk. The remainder of the non-cancer risk was divided 
between acetaldehyde, formaldehyde and manganese, with manganese 
contributing between 5.6 and 12.2 percent of the non-cancer risk, 
depending on the scenario. Under all scenarios, methanol, benzene, 
methylene chloride and phenol did not contribute at all to the non-
cancer risk from wood products affected sources (with one exception, 
where the phenol risk contribution was 0.1 percent). Based on these 
results, the commenter stated that there appeared to be little reason 
to include evaluation of methylene chloride or benzene in the risk-
based compliance option. However, the commenter stated that it may be 
reasonable to take an extremely conservative approach and include 
evaluation of manganese in the risk-based compliance mechanisms.
    Response: We agree that it is appropriate to limit the number of 
HAP that must be included in PCWP affected source low-risk 
demonstrations to only those HAP that may possibly result in meaningful 
contributions to the affected source risk. However, we disagree that 
limiting the HAP included in the low-risk demonstration to the six HAP 
defined as total HAP in subpart DDDD of 40 CFR part 63 (acrolein, 
acetaldehyde, formaldehyde, methanol, phenol, and propionaldehyde) is 
appropriate. 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). As discussed 
earlier in this preamble, 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 risk 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. To ensure protection of public health, 
all HAP must be considered when determining which affected sources are 
low risk. Simply importing the surrogate pollutants that are reasonably 
used for MACT purposes into the risk assessment context is not 
appropriate, as surrogacy for MACT is based on factors and 
considerations relating to technological control capabilities and not 
on how surrogate pollutants might indicate how non-surrogates affect 
risks to human health and the environment. For example, just because in 
many cases particulate matter is a useful surrogate for measuring the 
control efficiency of devices used to capture non-mercury HAP metals, 
that fact is unrelated to what risks the HAP metals may present 
individually or collectively, as HAP metals apart from the risks they 
pose as being particulates.
    The commenter is correct in that our preliminary risk analysis 
conducted prior to proposal 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 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 low-risk demonstrations. 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 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 low-risk 
demonstration 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.
Background, Multipathway, and Ecological Exposures
    Comment: Two commenters argued that multipathway exposures should 
not be considered for PCWP affected sources. One commenter stated that, 
because the HAP emitted from the PCWP source category are not 
bioaccumulative, it is unnecessary to consider multipathway exposures. 
The other commenter stated that there is no policy basis for 
considering multipathway exposures because U.S. Government surveys and 
regulatory actions demonstrate that non-inhalation exposure to the six 
HAP emitted by wood products affected sources is insignificant. The 
commenter provided rationale for the conclusion that dietary and 
drinking water exposures to the six HAP are not significant. Because 
the six HAP primarily emitted from the PCWP source category 
(acetaldehyde, acrolein, and formaldehyde, methanol, phenol, and 
propionaldehyde) do not exhibit bioaccumulative characteristics, the 
commenter considered it unnecessary to consider multipathway exposures.
    Three commenters argued that multipathway exposures should be 
considered for PCWP facilities. One commenter stated that, when 
persistent biological toxicant or metal emissions are significant, 
ingestion and other pathways should be considered in the risk 
screening. Another commenter stated that the concentration-based 
applicability threshold approach in the proposed PCWP rule does not 
address non-inhalation exposures or adverse effects on the environment. 
The third commenter stated that CAA section 112(d)(4) requires EPA to 
consider all possible ways that a pollutant could affect human health 
or the environment because it refers to pollutants ``for which a health 
threshold has been established,'' i.e., pollutants that have no adverse 
health or environmental effects. (See 5 Legislative History at 8511.) 
According to the commenter, EPA has recognized repeatedly in the past 
that many of the pollutants emitted by the source category are re-
deposited from the atmosphere and then contaminate soil and water for 
long periods of time. The commenter added that these pollutants 
bioaccumulate in wildlife and food sources, poisoning people and 
animals alike. The commenter concluded that, to evaluate whether a 
pollutant is a threshold pollutant and what its health threshold and 
ample margin of safety must be, EPA must consider all the potential 
health and environmental effects of

[[Page 45998]]

deposition, persistence and bioaccumulation of that pollutant. The 
commenter argued that EPA would contravene section 112(d)(4) by 
considering only health effects caused by inhalation.
    Response: This rule is relying not on CAA section 112(d)(4), but on 
section 112(c)(9), which states that potential ecological effects and 
multimedia human exposures need to be considered. We have conducted an 
ecological assessment and a multipathway exposure assessment on those 
HAP emitted from PCWP affected sources (including HAP not among the six 
mentioned by one commenter) that we have identified as having the 
potential for persisting and bioaccumulating in the environment. From 
this analysis we determined that adverse ecological effects and/or 
multimedia health effects are unlikely from PCWP affected sources. 
Therefore, PCWP affected sources attempting to demonstrate their low-
risk status will not be required to include an ecological assessment or 
a multimedia assessment.
    Comment: Several commenters stated that there is no legal or policy 
basis for EPA to consider background or multipathway (non-inhalation) 
exposures. The commenters claimed that CAA section 112(d) requires that 
MACT standards be based only on emissions from the MACT-regulated 
portion of the facility; it does not give EPA the authority to consider 
existing background levels. One commenter asserted that CAA section 112 
can be distinguished from other statutory provisions, both in the CAA 
and in other environmental legislation, where EPA has clearly been 
given authority to consider background sources.
    Another commenter argued that the CAA's legislative history does 
not support a requirement to consider other exposures. The commenter 
also claimed that the statutory provisions on which EPA would rely to 
implement the risk-based mechanisms (i.e., CAA section 112(d)(4), CAA 
section 112(c)(9)(B), or EPA's de minimis authority) exclusively focus 
on the emissions from the source in making regulatory decisions. 
According to the commenter, EPA has existing regulatory programs (e.g., 
for mobile and area sources (Urban Air Toxics Strategy)) in place to 
address HAP emissions from other sources.
    The commenter argued that over-control of PCWP affected sources is 
unjustified because PCWP affected sources account for very small 
proportions of HAP emissions nationwide-less than 1.75 percent of 
acetaldehyde, 1.7 percent of acrolein, and 1 percent of formaldehyde 
emissions, according to their industry-sponsored risk assessment. Given 
these results, the commenter concluded that PCWP facilities cannot 
reasonably be considered to contribute meaningfully to background 
concentrations.
    The commenter stated that delisting criteria and the so-called 
trigger component of the residual risk provision focus exclusively on 
emissions and whether the risk posed by any source in the category, by 
itself, exceeds one in a million cancer.
    Two commenters opposed the use of available data on background 
concentrations and facility-specific measurement of background 
concentrations to determine the extent of exposures from other sources, 
arguing that the CAA and sound public policy warrant a focus 
exclusively on the emissions from the source category at hand when 
evaluating the applicability of a risk-based compliance option. Because 
a HI of 1.0 (or higher) is amply protective of public health and is 
warranted under EPA's statutory mandate, the commenters stated that 
consideration of background concentration is not appropriate.
    Response: For the purposes of this rulemaking, we are not 
considering background HAP emissions as part of the CAA section 
112(c)(9) delisting of the low-risk PCWP subcategory. As we indicated 
in the Residual Risk Report to Congress, however, the Agency intends to 
consider facility-wide HAP emissions in future CAA section 112(f) 
residual risk actions.
    Regarding multipathway exposures, the industry's wood products MACT 
risk assessment does not address HAP emitted from PCWP affected sources 
that have the potential to bioaccumulate and persist in the environment 
(e.g., lead, cadmium, and mercury). We conducted an exposure assessment 
for these HAP to determine exposure from ingestion as well as 
inhalation. The maximum multipathway risks were considerably lower than 
the predicted maximum inhalation risks from the PCWP source category. 
Therefore, PCWP affected sources are not required to conduct site-
specific multipathway risk assessments as part of their low risk 
demonstrations. The look-up tables included in appendix B to subpart 
DDDD were developed using conservative input parameters to ensure that 
affected sources qualifying for the low-risk subcategory based on the 
look-up tables would not pose a risk via multipathway exposures.
    As discussed elsewhere in this preamble, for today's final PCWP 
rule, we consider that an HI limit of 1.0 provides an ample margin of 
safety for protecting public health under CAA section 112(c)(9) for 
this delisting of low-risk PCWP affected sources. The RfCs that are 
used to calculate the HI are developed to protect sensitive subgroups 
and to account for scientific uncertainties, ensuring that the use of 
an HI limit of 1.0 provides an ample margin of safety. We conclude that 
an HI limit of 1.0 is appropriate for the section 112(c)(9) 
demonstrations for the PCWP source category that are described in 
today's action. In future risk-based actions for this and other source 
categories (e.g., residual risk rulemakings under CAA section 112(f)) 
we may identify factors on a case-by-case basis that would lead us to 
conclude that HI limits other than 1.0 would be more appropriate for 
those other actions.
    The look-up tables included in appendix B to subpart DDDD of 40 CFR 
part 63 were developed based on an HI of 1.0. For site-specific chronic 
inhalation risk assessments, affected sources are required to ensure 
that their TOSHI (or, alternately, a site-specific set of hazard 
indices based on mechanistic data or dose-response data for their HAP 
mixture) are less than or equal to a value of 1.0. These assessments 
focus on respiratory effects and CNS effects, because based on our 
analysis noncancer impacts were dominated primarily by impacts on these 
systems. Other target organs or systems were found to be negligibly 
impacted.
    Comment: One commenter stated that EPA had provided inadequate 
discussion of how environmental risks would be evaluated. The commenter 
added that the CAA requires EPA consider the environment as well as 
public health, and that, at a minimum, a facility would be required to 
conduct an assessment based on EPA's 1998 Guidelines for Ecosystem 
Assessment. The commenter referred EPA to appendix A of ``Generic 
Assessment for Endpoints for Ecological Risk Assessment'' for a 
detailed discussion on the legal basis from ``such statutes as the CAA 
* * * that require EPA to consider and protect organism-level 
attributes or various taxa including fish, birds, and plants and more 
generally, animals, wildlife, aquatic life, and living things.''
    Another commenter cited an analysis they commissioned that showed 
it to be highly unlikely that emissions from PCWP facilities would pose 
a hazard to ecological receptors at levels that are protective of human 
health. Thus, concern over ecological receptors would not provide a 
valid basis for reducing the HI below 1.0.

[[Page 45999]]

    Response: An ecological assessment is required under sections 
112(d)(4), (c)(9), and (f)(2) of the CAA regarding the presence or 
absence of ``adverse environmental effects'' as that term is defined in 
CAA section 112(a)(7). Therefore, delisting under section 112(c)(9) 
requires consideration of ecological effects. The look-up tables 
developed for today's final PCWP rule are intended to accommodate 
enough conservatism that any affected source qualifying for inclusion 
in the delisted subcategory using them will qualify based on all 
endpoints, including ecological endpoints. Based on our analysis of 
ecological effects (in the supporting information for the final rule), 
we feel it is unlikely that PCWP affected sources would pose any 
significant ecological risks to any actual ecosystem or ecosystems 
nearby. We also conclude, given the low impacts from the hypothetical 
worst-case scenario investigated, that it is unlikely that any 
potentially-exposed threatened or endangered species would be adversely 
affected by HAP emissions from these affected sources. Therefore, PCWP 
affected sources are not required to conduct site-specific ecological 
risk assessments as part of their low-risk demonstration.
    Assuming the assessment referenced by the first commenter included 
only the six HAP listed in subpart DDDD of 40 CFR part 63, we disagree 
that these six HAP should be the sole focus of an ecological 
assessment. It is not clear from the comment whether the commenter is 
suggesting that we might consider lowering the human health HI values 
to below 1.0 in order to reflect ecological concerns or whether they 
are suggesting that an ecological HI value should not be reduced below 
1.0. In the former case, that is not done. Human health and ecological 
assessments are independent assessments with their own risk management 
criteria.
Hazard Index
    Comment: Two commenters stated that hazard quotients (HQ) for 
chemical mixes should not be summed to determine the HI unless the 
primary effects are on the same organ by the same mechanism; otherwise 
the risk would be overestimated. One commenter stated that CAA section 
112(d)(4) refers to threshold pollutants, with each health threshold 
augmented by an ample margin of safety. These ample margin of safety 
values are already incorporated into RfC values. The risk criteria 
applied are confined to the effects upon which the RfC is based, which 
reflect the most sensitive target organ. According to the commenter, a 
decision to add risk posed by chemicals that affect the same target 
organ but have unknown mechanisms of action represents an unnecessarily 
conservative assumption that would tend to inflate the final risk 
estimate.
    The commenters also noted that, according to the National Research 
Council and the Presidential/Congressional Commission on Risk 
Assessment and Risk Management, additivity at low doses is more likely 
to overestimate than to underestimate total risk. As stated in the 
Commission's 1997 Final Report: ``When the individual components of a 
chemical mixture exhibit different kinds of toxicity or have different 
biological mechanisms of toxicity, they do not interact--they act 
independently at low doses. In that case, the dose-response 
relationships for each chemical should be considered independently * * 
* [By contrast] studies in which similar chemicals with similar 
mechanisms and target were administered simultaneously indicate that 
antagonism is the usual outcome * * * '' (Falk and Kotin 1964, Schmal 
et al. 1977)
    Response: Our recommended approach for assessing risks from 
exposure to a mixture of pollutants is to utilize a dose-response 
assessment developed for that mixture.4 5 There are few 
mixtures (e.g., coke oven emissions), however, for which such 
assessments are available. When mixture-specific dose-response 
assessments are not available, a component-by-component approach is 
recommended. The method for component data depends on a judgment of 
toxicologic similarity among components. The specific term toxicologic 
similarity represents a general knowledge about the action of a 
chemical or a mixture and can be expressed in broad terms such as at 
the target organ level in the body. In our guidance, assumptions about 
toxicologic similarity are made in order to choose among risk 
assessment methods. In general, we assume a similar mode of action 
across mixtures or mixture components and, in some cases, this 
requirement may be relaxed to require that these chemicals act only on 
the same target organ.\6\
---------------------------------------------------------------------------

    \4\ U.S. Environmental Protection Agency. 1986. Guidance for 
Conducting Health Risk Assessment of Chemical Mixtures. Risk 
Assessment Forum, Washington, DC. EPA/630/R-98/002; available at 
http://cfpub.epa.gov/ncea/raf/recordisplay.cfm?deid=20533. (EPA 
1986).
    \5\ U.S. Environmental Protection Agency. 2000. Supplementary 
Guidance for Conducting Health Risk Assessment of Chemical Mixtures. 
Office of Research and Development. EPA/630/R-00/002 (EPA 2000).
    \6\ Ibid.
---------------------------------------------------------------------------

    The primary method for component-based risk assessment of 
toxicologically similar chemicals is the HI, which is derived from dose 
addition. In our guidance, dose addition is interpreted as simple 
similar action, where the component chemicals act as if they are 
dilutions or concentrations of each other differing only in relative 
toxicity. Dose additivity may not hold for all toxic effects. 
Furthermore, the relative toxic potency between chemicals may differ 
from different types of toxicity or toxicity by different routes. To 
reflect these differences, the HI is then usually developed for each 
exposure route of interest, and for a single specific toxic effect of 
toxicity to a single target organ. A mixture may then be assessed by 
several HI, each representing one route and one toxic effect or target 
organ.\7\
---------------------------------------------------------------------------

    \7\ Ibid.
---------------------------------------------------------------------------

    To assess the cumulative risk or hazard associated with nonlinear 
effects of HAP in our analysis of PCWP affected sources, HAP hazard 
quotients pertaining to the same target organs or systems are summed to 
generate TOSHI. While it may be preferable to focus on the addition of 
HAP HQ that involve similar or complementary mechanisms or mode of 
action, that level of information is not generally available for all of 
the HAP on which we are focusing. Pending the availability of such data 
for the HAP components of the mixture being assessed, the default 
method employed under CAA section 112(c)(9) is to aggregate HAP HQ by 
target organ to generate a TOSHI.
    Comment: Two commenters supported a HI of 1.0 (or greater) as an 
appropriate benchmark for comparing exposures attributable to affected 
source emissions, which should fully provide for the statutory mandate 
of an ample margin of safety. The commenters referred to the 1997 Final 
Report of the Presidential/Congressional Commission on Risk Assessment 
and Risk Management in Regulatory Decision-Making as support for their 
position. Specifically, the Commission supported a noncancer HI of 
10.0, stating that there are few HAP with RfC values within a factor of 
10 of their no observable adverse effects level (NOAEL). Because RfC 
values are typically one-thousandth of a NOAEL, a noncancer HI of 10.0 
in those cases would still leave a margin of exposure of 100. The 
Commission recommended that EPA should, on the basis of screening 
assessments of source categories, do further risk assessment and 
analysis of categories where the noncancer HI exceeds 10.0. Where more 
detailed risk assessments yield noncancer hazard indices less than 1.0,

[[Page 46000]]

the Commission recommended that no further action be required. The 
commenters agreed that sources should not be required to go below that 
level (e.g., to an arbitrary level such as 0.2), arguing that EPA has 
neither a legal mandate nor a rational basis for limiting the HI to 
less than 1.0.
    One of the commenters stated that the comparison of RfC or 
similarly-derived health benchmarks to modeled maximum annual average 
concentrations is extremely health-protective and meets the ample 
margin of safety requirement of the statute. Given this high degree of 
conservatism, the commenter stated that neither the CAA nor sound 
policy requires that background and multipathway exposures be 
incorporated into an evaluation of the degree of risk posed by affected 
sources. Under these circumstances, the commenter argued, the mere 
possibility of exposure from multiple sources, or multiple HAP from a 
single source, does not justify a uniform adjustment to all RfC values 
or similarly-derived health benchmarks for all affected sources. 
Similarly, the commenter believed that EPA should not mandate modeling 
risks from the entire facility, but rather only from the portions of 
the facility that are within the source category.
    Two other commenters objected to a noncancer HI of 1.0 (or 
greater). The first commenter stated that, while the HI is useful in 
evaluating site-specific impacts, choosing a generic HI (some multiple 
of 1.0) for application to a wide range of sites is inappropriate. The 
commenter added that selection of an arbitrary multiple of 1.0 is not 
science, does not conform with CAA section 112(d)(4), and does not 
protect public health. The commenter stated that the selection of a HI 
of 0.2 as a rough screening tool seemed reasonable, although it was 
unsupported by any analysis. The commenter added that if a default HI 
is used, then EPA should include a provision that would disallow its 
use to exclude a facility from MACT if better background information is 
available suggesting the default HI does not protect public health. 
However, the commenter believed that the CAA does not support an 
interpretation that includes the use of such a default to allow 
exemptions for individual sources. The commenter believed that the 
expansion of the interpretation to include non-threshold pollutants is 
in direct conflict with section 112(d)(4).
    The second commenter evaluated the four potential options that EPA 
proposed to ensure that a risk analysis under CAA section 112(d)(4) 
considered the total ambient air concentrations of all the HAP to which 
the public is exposed. Option 1, which requires that the HI for all 
pollutants be no greater than 1.0, does not consider additional sources 
or background and is unacceptable, according to the commenter. Option 
3, which uses existing data such as NATA to determine background and 
requires that the HI be no greater than 1.0, is also unacceptable, 
according to the commenter. The commenter pointed out that EPA has 
clearly stated at public meetings that the NATA is not to be used to 
make regulatory decisions. (As the first commenter noted, NATA 
information includes warnings that the information is useful for large-
scale planning purposes and not for local area assessment.) The 
commenter added that NATA relies on data submitted to EPA voluntarily 
and has been reported to consistently underestimate measured 
concentrations. Until EPA requires that HAP inventories be submitted as 
proposed in the Consolidated Emissions Reporting Rule (CERR), and the 
NATA conducts refined modeling around stationary sources, the commenter 
argued that NATA should not be considered for estimating background 
concentrations. Option 4, which allows individual affected sources to 
monitor the HAP backgrounds for use in their own analysis, requires 
oversight and evaluation by the States to ensure proper site selections 
and analytical methods and should not be considered, according to the 
commenter. The commenter believed Option 2, which requires that the HI 
be no greater than 0.2, would be the only viable option at this time 
using a conservative risk screening analysis. However, the commenter 
did not endorse using any of the proposed threshold limit applicability 
methods to exempt process sources from NESHAP requirements.
    Two other commenters raised additional objections to EPA's proposed 
methodologies for determining the contribution of other sources to the 
overall hazard. The first commenter stated that EPA had not discussed 
the need to assess cumulative risks, aggregate exposures, and health 
impacts associated with exposure to chemical mixtures emitted from 
affected sources within the source categories. The commenter referred 
EPA to the extensive progress that has been made in more completely 
addressing risks from exposure to air pollution and integrated 
decisionmaking in such areas as children's risk issues, cumulative 
exposure, and chemical mixtures. The commenter requested that the 
recent advancements be incorporated into the risk assessment methods 
and overall cost estimates associated with risk-based exemptions in the 
proposed rules.
    The second commenter stated that EPA's proposed alternative 
methodologies for determining the contribution of other sources to 
cumulative risk are untenable and deeply flawed. According to the 
commenter, the first and second approaches (HI of 1.0 and HI of 0.2) 
would allow exemptions based on blanket assumptions about exposure, but 
EPA provided no basis for making any assumption. The commenter noted 
that the third option suggests relying on existing estimates of 
background levels of certain HAP, but argued that these information 
sources (e.g., NATA, ATSDR) are neither designed nor adequately precise 
to be used as the basis of regulatory applicability determinations. 
According to the commenter, EPA has cautioned that NATA emission 
estimates ``cannot be used to identify exposures and risks for specific 
individuals, or even to identify exposures and risks in small 
geographic regions such as a specific census tract.'' (U.S. EPA, 
Limitations in the 1996 National-Scale Air Toxics Assessment) The 
commenter pointed out that NATA does not estimate exposure to a number 
of HAP, (e.g., hydrogen fluoride (HF), HCl), and the ATSDR profiles 
offer generalized assessments, but are not specific enough to establish 
as baseline for a given facility.
    Response: For today's final PCWP rule, we are considering an HI 
limit of 1.0 to provide an ample margin of safety for protecting public 
health under CAA section 112(c)(9). However, we do not feel that 
increasing the HI limit above 1.0 is justified by currently available 
science. Safety factors are included in the dose-response values used 
to calculate the HI to account for scientific uncertainties, and their 
inclusion helps ensure that using a HI limit of 1.0 provides an ample 
margin of safety. The TOSHI approach for site-specific risk assessment 
in today's final PCWP rule assumes additivity in mixtures of chemicals 
that target the same organ system. For their site-specific risk 
assessments, affected sources are encouraged to determine TOSHI for 
respiratory and CNS effects to simplify analysis. More detailed 
analysis of mixture additivity, incorporating mechanistic data and 
uncertainty and including dose-response data for specific mixtures, 
where available, may also be included in site-specific analyses using 
scientifically-accepted, peer-reviewed methodologies. Based on our 
analysis, noncancer impacts were dominated primarily by impacts on

[[Page 46001]]

these systems and other target organ systems were found to be 
negligibly impacted. We are not using background concentrations from 
NATA in today's final PCWP rule. Several commenters presumed the use of 
CAA section 112(d)(4) for the PCWP rule as proposed. However, we are 
using CAA section 112(c)(9) and not section 112(d)(4). Discussion of 
our authority to consider background and multipathway exposures is 
provided elsewhere in this section.
Tiered Approach
    Comment: Several commenters supported EPA's proposed tiered 
modeling approach, which begins with simple look-up tables and 
progresses to more refined facility-specific risk assessments. One 
commenter noted that the State of Wisconsin uses a tiered approach 
similar to the approach proposed by EPA, and in general, this approach 
has worked well. The approach first allows sources to demonstrate 
compliance if their potential emissions, stack height, and exhaust 
direction are within the ranges provided in conservative look-up 
tables. The second tier allows facilities to provide site-specific 
modeling to demonstrate compliance with ambient air standards at the 
property line. Another commenter added that EPA should be flexible in 
accepting evolving improvements in exposure assessment and risk 
modeling, and should take into account the inherent strengths and 
weaknesses of the types of modeling used. A third commenter noted that 
most sources would use the tiered modeling approach but believed that 
facilities should be allowed to use any EPA-approved modeling technique 
to demonstrate that their emissions are below the applicable health 
benchmark. The commenter also recommended that, for the final PCWP 
rule, EPA adopt the model regulatory text that they provided for the 
risk-based framework.
    One commenter opposed EPA's proposed tiered modeling approach, 
stating that if EPA decided to pursue a generic risk screening approach 
under section 112(d)(4), it would need to be conservative. According to 
the commenter, the use of a (non-tiered) conservative approach would 
represent the least cost to the regulated community and would be the 
least time-consuming for States reviewing the facility's application.
    Response: We acknowledge the model regulatory text submitted by one 
of the commenters. However, as discussed elsewhere, we developed our 
own regulatory text to specify how affected sources must demonstrate 
that they are part of the low-risk subcategory through low-risk 
demonstrations. Also, we will be reviewing the low-risk demonstrations 
submitted by PCWP affected sources to remove the burden of reviewing 
risk assessments from States.
    We will review all risk assessments performed in support of a 
demonstration of eligibility for the low-risk subcategory with regard 
to a variety of aspects, including the consistency of the methodology 
and modeling techniques with those currently accepted by the scientific 
community and EPA. However, we will consider assessments that use risk 
methodology and modeling techniques in addition to or in lieu of those 
described in EPA's ``Air Toxics Risk Assessment Reference Library,'' as 
appropriate, provided they have undergone scientific peer review 
pertinent to their use in the submitted assessment.
    Comment: One commenter stated that, for EPA to conduct an up-front 
risk analysis, the procedure would need to be conducted using the most 
conservative stack parameters, with a hypothetical facility fence line 
to satisfy the many impact scenarios that could occur.
    Response: We conducted a rough risk assessment to estimate the 
number of PCWP affected sources that might qualify for the delisted 
low-risk subcategory. The data used in our rough risk assessment were a 
combination of facility-specific data (e.g., process unit throughput) 
and industry average data (e.g., industry average stack parameters, 
average emission factors for estimating emissions). Facilities do not 
qualify for the low-risk subcategory based on our rough risk 
assessment, with the exception of eight affected sources who were 
determined to pose very low risk based on our analysis (i.e., with 
TOSHI less than 0.1, and a cancer risk of less than 0.1 in 1 million). 
However, affected sources can qualify for inclusion in the delisted 
subcategory by using site-specific emissions test data and the look-up 
tables or by conducting a low-risk demonstration, as described in 
appendix B to subpart DDDD of 40 CFR part 63 and in other analytical 
tools such as the ``Air Toxics Risk Assessment Reference Library,'' 
(which may be appropriate for specific sources). Look-up tables were 
developed using the health-protective air dispersion model SCREEN3. 
Stack height and fenceline distance vary in the tables, so affected 
sources will choose the most appropriate combination of these 
parameters. Invariant facility parameters built into the look-up tables 
are either average values or biased towards health-protective values, 
based on available data. Thus, we believe the look-up tables are 
appropriately health-protective to accommodate the many impact 
scenarios that could occur.
Risk Assessment Guidance
    Comment: Several commenters stated that EPA neglected to follow its 
own guidelines and science policies in its proposal for risk-based 
exemptions. One commenter argued that EPA had proposed a disorganized 
and cursory approach to implement risk-based exemptions that fell far 
below the quality of risk analysis typically required by EPA across its 
other programs. According to the commenter, the proposal did not adhere 
to EPA's established guidelines for characterizing human health and 
ecological risks, did not incorporate risk assessment guidelines for 
conducting multi-pathway risk assessments, and did not reference EPA 
guidelines for cumulative risk assessment that specifically require 
consideration of non-inhalation pathways. The commenter noted that 
EPA's March 1995 Risk Characterization Policy set goals of 
transparency, clarity, consistency, and reasonableness which apply to 
risk assessment practices across EPA. The commenter argued that the 
inconsistencies between EPA's proposal to provide risk-based exemptions 
in the MACT standard process and its risk assessment guidelines would 
undermine many regulatory programs throughout EPA.
    The commenter stated that the risk-based scheme was based on a 
fundamental misunderstanding of the use of public health and ecological 
risk assessments in the regulatory process. The commenter added that 
the Federal risk assessment guidelines require EPA to conduct risk 
assessments consistently across all Federal environmental programs. 
According to the commenter, the approaches outlined by industry's white 
papers neglected to include risk characterization, which provides 
needed and appropriate information to decision makers. The approaches 
also did not incorporate the critical recommendation of the Commission 
of Risk Assessment and Risk Management to establish a framework for 
stakeholder-based risk management decision making. The commenter stated 
that these omissions in the proposal would prevent regulatory agencies 
from demonstrating to the public that public health and the environment 
are adequately protected.
    Several commenters stated that EPA also needed to be consistent 
with residual risk guidelines currently under development. One 
commenter stated that the tools needed to identify sources

[[Page 46002]]

eligible for the risk-based exemption would be the same tools necessary 
for a CAA section 112(f) residual risk assessment, which the commenter 
understood were not yet ready for general use. Another commenter noted 
that the cancer risk guidelines are currently undergoing public review.
    A third commenter stated they had serious reservations about EPA's 
apparent attempt to conduct an ad-hoc risk analysis for specific source 
categories by seeking comments on the specific elements to be included 
in the risk analysis. The commenter did not believe these rulemakings 
were an adequate forum to develop this risk analysis process. The 
commenter indicated that any risk analysis conducted by the EPA must 
adhere to the risk assessment principles outlined in the Residual Risk 
Report to Congress.
    One commenter argued that the proposal is consistent with EPA risk 
assessment guidelines and policies and believed that others' technical 
objections were without merit. The commenter added that the 
contemplated risk-based applicability criteria were not in conflict 
with the classification of carcinogens and noncarcinogens.
    Response: We discussed a tiered analytical approach in the preamble 
to the proposed rule, beginning with relatively simple lookup tables 
and followed by increasingly more site-specific but more resource 
intensive tiers of analysis, with each tier being more refined. In 
today's final rule, we are adopting a somewhat different approach for 
meeting the requirements of CAA section 112(c)(9), as discussed 
elsewhere in this preamble. The basis for this approach stems from the 
general air toxics assessment approach presented in the Residual Risk 
Report to Congress, which was developed with full consideration of EPA 
risk assessment policy, guidance, and methodology.
    Section 112(c)(9) of the CAA requires us to determine whether the 
public and the environment are protected. Any analyses we did to 
establish the feasibility of the risk-based approach or to develop 
health-protective look-up tables included consideration of human health 
as well as ecological criteria. The supporting information to the final 
rule details the assessment we conducted to determine the feasibility 
of delisting a low-risk subcategory and the look-up tables we developed 
to be used by affected sources in their demonstrations, thereby 
providing a public demonstration of the method employed to ensure 
protection of the public health and environment in decisions associated 
with this rule. Additionally, protection against the potential for 
exposures via non-inhalation pathways (e.g., ingestion) for persistent, 
bioaccumulative HAP is also inherent in the values in the look-up 
tables. As discussed previously, and in the supporting information for 
the final rule, we conducted a screening assessment of multipathway and 
ecological effects for the PCWP source category. We concluded that 
multipathway risks are considerably lower than predicted maximum 
inhalation risks and that it is unlikely that PCWP affected sources 
would pose any significant risk to nearby ecosystems. Therefore, 
affected sources are not required to conduct site-specific multipathway 
and ecological risk assessments as part of their low-risk 
demonstrations.
    We agree that the tools needed to identify sources eligible for the 
delisted low-risk subcategory of PCWP facilities are the same tools 
necessary for a CAA section 112(f) residual risk assessment. And, as 
stated in the Residual Risk Report to Congress, we intend to rely on 
the general methodology and process illustrated by the framework 
presented in that report in our risk assessment activities throughout 
the air toxics program. Affected sources must demonstrate eligibility 
for the delisted low-risk subcategory using either a look-up table 
analysis (based on the look-up tables included in appendix B to subpart 
DDDD of this part) or using the suggested site-specific methodology 
described together with the criteria in appendix B to subpart DDDD of 
this part. The ``Air Toxics Risk Assessment Library,'' developed 
specifically for EPA's Residual Risk program, is provided as an example 
of one document that could be used for these facility-specific risk 
assessments. This document has been peer-reviewed and was developed 
according to the principles, tools and methods outlined in the Residual 
Risk Report to Congress. However, it may not be appropriate for all 
sources, and for that reason sources and EPA may consider alternative 
analytical tools for these risk assessments.
    The comment that the new cancer guidelines are still under review 
is correct but, as stated in the November 29, 2001 Federal Register 
notice (66 FR 59593), these 1999 draft guidelines are to be considered 
the interim guidance.\8\
---------------------------------------------------------------------------

    \8\ U.S. EPA. 1999. Guidelines for Carcinogen Risk Assessment. 
NCEA-F-0644. Risk Assessment Forum, Washington, DC.
---------------------------------------------------------------------------

4. Implementation
State and Local Resources
    Comment: Several commenters contended that the proposal would place 
a very intensive resource demand on State and local agencies (e.g., 
permitting authorities) to review sources' risk assessments. State and 
local agencies may not have expertise in risk assessment methodology or 
the resources needed to verify information submitted with each risk 
assessment. The commenters argued that, if EPA intends to have the 
affected industries conduct the analysis, then EPA must consider the 
cost incurred by States, which may lack the necessary expertise to 
evaluate and review these analyses.
    One commenter pointed out that the proposal only considered cost 
for the regulated source category, and not for regulatory agencies. 
According to the commenter, EPA did not consider the cost and resources 
associated with the following: (1) The public process required in 
reviewing and approving the proposed approaches and, if approved, 
making substantial changes to existing regulations; (2) the development 
of methods and guidance for human health and ecological risk 
assessments of affected sources; (3) the review by already budgetarily 
constrained State agencies of the assessments and assurance of adequate 
public participation in the process; and (4) the collection and 
verification of source-specific data needed for conducting risk 
assessments (e.g., emissions data and stack parameters). The commenter 
added that the proposal did not address the critical need for qualified 
risk assessors to evaluate the scientific and technical basis for 
exempting affected sources from regulation on a case-by-case basis. The 
commenter estimated that if one additional full-time employee (FTE) 
were required per State to review risk-based exemptions, then the cost 
would be an additional $7.5 million annually.
    Another commenter pointed out that the ongoing assurance that low-
risk affected sources remain low risk would also increase the burden 
for the State and local agencies. The commenter also stated that 
diverting State and local resources to focus on presumably 
insignificant sources would detract from efforts associated with 
significant sources.
    A third commenter stated that, since States generally do not have 
the right staff or resources to hire additional staff to review lengthy 
and complex risk analyses, they may refuse delegation of the PCWP rule, 
which would shift the burden to EPA in a time of tight

[[Page 46003]]

budgets. According to the commenter, large expenditures are not 
justified when only a small number of facilities may end up qualifying 
for an exemption.
    By contrast, several commenters stated that a risk-based program 
approaches could be structured and implemented in a manner that would 
not impose a substantial cost or resource burden on States. One 
commenter stated that assuring compliance with risk-based applicability 
criteria would be straightforward and would not entail an added 
resource burden. Another commenter suggested that EPA work closely with 
States and industry to implement the risk-based approach in a non-
burdensome manner. Two commenters stated that the risk-based 
approaches, like other MACT standards, would simply be incorporated 
into each State's existing title V program. Because the title V 
framework already exists, the addition of a risk-based MACT standard 
would not require States to overhaul existing permitting programs. One 
commenter stated that the risk-based approach would not increase the 
number of sources regulated by each State. The commenter believed that 
the final MACT rule itself should set forth the applicability criteria, 
including the threshold levels of exposure, that sources must meet to 
qualify for a risk-based determination. Each source would have the 
burden of demonstrating that its exposures are below this limit, and, 
therefore, the States would not be required to develop their own risk 
assessment guidance or to conduct source-specific risk assessments. One 
commenter stated that the risk assessment guidance to be issued by EPA 
within the next several months would streamline the risk-based approach 
and further reduce any burden on the States. Three commenters supported 
having States charge reasonable increased fees (as a component of 
annual operating permit fees or other fees) to cover any significant 
additional workload demands associated with reviewing more-detailed 
tier 2/3 modeling.
    Response: We acknowledge that review of the eligibility 
demonstrations for the delisted low-risk subcategory will require 
resources for verification of information and may require expertise in 
risk assessment methodology that is not yet available in some States. 
We also acknowledge that States may choose to reject delegation of the 
final PCWP rule. To alleviate these concerns and to ensure consistency 
in the applicability determinations for the delisted low-risk 
subcategory from State-to-State, we will review and approve/disapprove 
the low-risk subcategory eligibility demonstrations submitted by PCWP 
facilities. As mentioned previously in this preamble, we encourage 
facilities to submit their assessments for review early to facilitate a 
timely review process.
    We have considered the above comments in developing the criteria 
defining the delisted low-risk subcategory of PCWP affected sources, 
and we feel that the approach that is included in today's final PCWP 
rule provides clear, flexible requirements and enforceable compliance 
parameters. Today's final PCWP rule provides two ways that an affected 
source may demonstrate that it is part of the delisted low-risk 
subcategory of PCWP affected sources. First, look-up tables, which are 
included in appendix B to subpart DDDD of this part, allow affected 
sources to determine, using a limited number of site-specific input 
parameters, whether emissions from their sources might cause an HI 
limit to be exceeded. Finally, a site-specific modeling approach can be 
used by those affected sources that cannot demonstrate that they are 
part of the delisted low-risk subcategory using the look-up tables. 
With respect to guidance for performing low-risk demonstrations, one 
possible available set of procedures for performing risk assessments is 
discussed in EPA's ``Air Toxics Risk Assessment Reference Library,'' 
and may be used, where appropriate.
    Only a portion of the 223 PCWP major sources will submit 
eligibility demonstrations for low-risk subcategory. Of this portion of 
major sources, we feel that most will find themselves in the low-risk 
subcategory based on screening analyses (e.g., look-up table). However, 
it is likely that some facilities will submit more detailed risk 
modeling results. We are experienced in reviewing emission test results 
and site-specific risk assessments and will allocate resources for 
completion of these tasks. We will review and approve/disapprove low-
risk subcategory eligibility demonstrations based on look-up table 
analyses and low-risk demonstrations. Following review of each low-risk 
subcategory eligibility demonstration for a facility, we will issue a 
letter of approval/disapproval to the facility and will send a carbon 
copy to the facility's title V permitting authority to be used to 
develop source-specific permit terms and conditions that will ensure 
that the source remains eligible for the low risk subcategory. The 
letter of notification regarding approval/disapproval of an affected 
source's low risk demonstration will also be sent to any other 
interested stakeholders. The criteria for low-risk subcategory 
delisting are clearly spelled out in today's final PCWP rule, along 
with criteria needed to ensure that affected sources in the low-risk 
subcategory remain low risk. Because these requirements are clearly 
spelled out in today's final PCWP rule and because any standards or 
requirements created under CAA section 112 are considered applicable 
requirements under 40 CFR part 70, the terms and conditions 
demonstrating eligibility for membership in the delisted low-risk 
subcategory would be incorporated into title V permits, pursuant to 
State's existing permitting programs.
    With respect to the burden associated with ongoing assurance that 
affected sources remain low risk, 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 rendered an affected source low risk will be reflected 
in terms and conditions to be incorporated into the title V permit. We 
have developed continuous compliance requirements for affected sources 
that initially qualify as low risk, and the affected sources will be 
responsible for demonstrating that they continue to be low risk if 
changes are made to the affected sources' operations that would affect 
the risk that the affected sources pose to human health and the 
environment. We will review and approve/disapprove revised low-risk 
demonstrations.
    With respect to our consideration of the public process required in 
reviewing/approving the proposed approaches and making substantial 
changes to existing regulations, our inclusion of a risk-based 
compliance option in today's final PCWP rule applies only to the PCWP 
rule and does not directly impact other regulations. Furthermore, the 
PCWP proposal provided the public with the opportunity to comment on 
the consideration of risk in the final PCWP rule.
    Regarding the assurance of adequate public participation in the 
process of reviewing the risk analyses, the risk-based compliance 
options are part of a rule that was subject to public comment. The 
supporting information to the final rule details the assessment we 
conducted to determine the feasibility of delisting a low-risk 
subcategory and the look-up tables we developed to be used by affected 
sources in their demonstrations, thereby providing a public 
demonstration of the method employed to ensure protection of the public 
health and environment in

[[Page 46004]]

decisions associated with the final rule. We will be responsible for 
reviewing the low-risk demonstrations, but, similar to facilities 
requesting applicability determinations regarding promulgated 
standards, individual low-risk demonstrations will not be subject to 
public review and comment. We will, however, periodically publish 
updating notices in the Federal Register identifying any additional 
members of the low risk PCWP subcategory (or deletions therefrom), 
again, similarly to how we update notices regarding applicability 
determinations. These actions will represent final agency actions for 
purposes of judicial review under CAA section 307(b)(1). However, the 
parameters that rendered an a affected souce part of the low-risk 
subcategory will be incorporated into a title V permit and subject to 
the public review process through title V.
    Comment: One commenter stated that if EPA intends to have the 
affected industries conduct the analysis, then EPA must consider the 
additional cost incurred by smaller sources to do the analysis.
    Response: As mentioned previously, there are two ways that a PCWP 
facility may demonstrate eligibility for the delisted low-risk 
subcategory: (1) Look-up tables, and (2) a site-specific modeling 
approach that can be used by affected sources that cannot demonstrate 
eligibility for the delisted low-risk subcategory using the look-up 
tables. The look-up tables included in appendix B to subpart DDDD of 
this part allow affected sources to determine, using a limited number 
of site-specific input parameters, whether they are eligible for the 
low-risk subcategory. Attempting to demonstrate eligibility for the 
delisted low-risk subcategory is completely voluntary. Affected sources 
that are not eligible for the delisted low-risk subcategory based on 
look-up tables are not required to pursue a site-specific analysis 
(which can be increasingly complex and expensive as it becomes more 
refined). Each facility must weigh the costs of making a low-risk 
demonstration with the costs of MACT compliance. We feel that in 
general the costs associated with demonstrating eligibility for the 
low-risk subcategory will be lower than the costs associated with 
complying with MACT for many facilities, particularly smaller 
facilities and other facilities that have not already otherwise 
installed pollution controls. The majority of the cost associated with 
demonstrating eligibility for the delisted low-risk subcategory will be 
emissions testing costs. Smaller facilities have fewer process units to 
be tested, and, because of their lower production rates relative to 
larger facilities, they will also likely have lower emissions. Thus, 
smaller PCWP affected sources may be more likely than their larger 
counterparts to fall into the delisted low-risk subcategory. 
Successfully demonstrating eligibility for the low-risk provisions will 
result in cost-savings for smaller facilities because these facilities 
will not have to expend the costs (e.g., the costs of installing 
operating, and maintaining emission controls) for MACT compliance.
    The cost and economic analyses developed as part of the MACT 
rulemaking were based on the costs to install controls and comply with 
the MACT requirements. The costs associated with voluntarily conducting 
risk analyses were not estimated. Therefore, our estimate of costs 
associated with today's final PCWP rule are conservative, because the 
control costs are significantly higher than the costs of conducting 
emissions tests and risk analyses.
Title V
    Comment: Two commenters opposed implementing the risk-based 
approaches through the States' existing title V programs. One commenter 
stated that risk-based exemptions are such an implausible 
interpretation of the CAA that States do not even have the authority to 
grant them under their title V permit programs. The commenter was not 
aware of any approach to ensure that emissions remain below specified 
levels. According to the commenter, MACT standard applicability is the 
gate-keeper for being subject to a title V operating permit. Once a 
source is exempt from a MACT standard, it would be exempt from the 
monitoring, reporting and recordkeeping requirements needed to 
demonstrate compliance.
    The other commenter stated that implementing the CAA section 
112(d)(4) exemption interpretation through title V would be unlawful 
and unworkable. The commenter stated that Congress knew how to 
authorize States to establish case-by-case emission standards and 
implement them using post-rulemaking title V permits because it did so 
in CAA section 112(j). However, it did not do so in section 112(d)(4). 
The commenter argued that EPA lacks the authority to delegate section 
112(d)(4) to the States and may not implement any section 112(d)(4) 
applicability cutoff through a post-rulemaking mechanism such as a 
title V permit. With the exception of carefully delineated compliance 
monitoring, reporting, and certification provisions in the statute, 
title V permits may not create applicable requirements or exemptions 
from applicable requirements. The commenter added that, even if this 
approach is legal, it is still unworkable because of the resource 
challenges faced by States and the widespread delays in issuing title V 
permits. The commenter noted that State permit engineers and officials 
that prepare and issue title V permits generally are not experts in 
risk assessment or air dispersion modeling. According to the commenter, 
States and the public would be confronted with more self-serving 
facility arguments and data than could be adequately scrutinized, which 
could cause important health and risk determinations to be rubber 
stamped or cause the permit process to grind to a halt. The commenter 
added that most State title V permit programs are already behind the 
statute's permit issuance deadlines, and implementation of EPA's risk-
based approach would exacerbate this unlawful situation further.
    Several commenters supported implementing the risk-based approaches 
in the PCWP rule as proposed through the States' existing title V 
programs. One commenter suggested that States which qualify and choose 
to do so should be delegated the authority to implement the risk-based 
alternatives. The commenter added that this would allow States to 
coordinate between the MACT alternatives and State air toxics 
requirements.
    A second commenter stated that implementing the CAA section 
112(d)(4) risk-based approach though title V would be lawful and 
workable. According to the commenter, no facility-specific post-
rulemaking mechanisms nor expansion of the scope of title V permit 
process would be necessary, just the incorporation of the NESHAP's 
risk-based compliance option, which would contain the criteria for 
showing what the source would have to meet to qualify for the risk-
based approach. The commenter stated that the objections from other 
commenters to the risk-based criteria were invalid, arguing that their 
objections were in tension with the conclusions of a CAAAC Workgroup on 
State/Local/Tribal air toxics issues and that their comments provided 
no basis for concluding that States lack the legal authority to 
implement the risk-based approach.
    A third commenter noted that title V permits could provide 
enforceable limitations, appropriate recordkeeping requirements, and 
periodic review upon renewal. The commenter added that, since the PCWP 
rule would apply only to major sources, title V permits already are 
required and would not be an added

[[Page 46005]]

burden; title V could also be used to implement applicability cutoffs. 
However, the workload involved with the options requiring modeling, 
ambient monitoring, or other means to establish background 
concentrations would be a hindrance to any implementation mechanism. 
The commenter stated that, with respect to potential risk-based 
provisions, monitoring is more useful for demonstrating non-compliance 
than compliance because the regulation would apply to potential 
emissions under any weather conditions, whereas monitoring reflects 
current weather and emission conditions.
    A fourth commenter suggested changes to the Sec.  63.2240 of the 
proposed rule that would incorporate permitting procedures similar to 
those under 40 CFR part 70, which would allow facilities that pose 
little risk in their respective airsheds to apply for a risk 
determination to be incorporated into their title V permits. Each 
source applying to be permitted as a subcategorized toxic emitter with 
an acceptable risk determination would be required to perform detailed 
risk analyses for review by the public at large, local citizens, State 
agencies, and Federal authorities. This permitting exercise would allow 
managers of the airshed to develop custom-fit compliance plans that 
address source-specific risks and would allow the most flexibility for 
forest producers to reduce their identified risks.
    Response: As discussed previously, we have determined that a CAA 
section 112(d)(4) risk-based exemption would not be appropriate for the 
PCWP source category. Instead, using our discretion in establishing 
subcategories of sources based on size, type, class, or other 
appropriate criteria under CAA sections 112(d)(1) and (c)(1), we have 
established a low-risk subcategory of PCWP facilities, and delisted 
that subcategory under CAA section 112(c)(9)(B). The requirements for 
qualifying for and remaining in the delisted low-risk subcategory are 
clearly spelled out in appendix B to subpart DDDD of this part, and any 
standards or requirements created under CAA section 112 are considered 
applicable requirements under 40 CFR part 70. Unless a PCWP source 
meets these conditions, it will remain subject to the PCWP MACT rules. 
Therefore, the parameters used to demonstrate that facilities are part 
of the delisted low-risk subcategory would be incorporated into title V 
permits as federally enforceable permit terms, and States would not 
have to overhaul existing permitting programs. We note that our rules 
implementing title V of the CAA specifically provide for situations 
such as this. For example, in its provisions governing what types of 
permit revisions may proceed through the abbreviated ``minor permit 
modification'' process, our rules state that such procedures may not be 
used ``to establish or change a permit term or condition for which 
there is no corresponding underlying applicable requirement and that 
the source has assumed to avoid an applicable requirement to which the 
source would otherwise be subject.'' 40 CFR 70.7(e)(2)(i)(A)(4); 40 CFR 
71.7(e)(1)(i)(A)(4). We feel that permit terms reflecting a low risk 
PCWP source's eligibility clearly represent such terms, and are, 
therefore, allowed under title V. Also, such terms would be required to 
be added or revised through the more formal ``significant 
modification'' procedures of 40 CFR 70.7(e)(4) and 40 CFR 71.7(e)(3).
    Facilities that qualify as part of the delisted low-risk 
subcategory will initially demonstrate that they are low-risk using 
either the look-up tables or site-specific monitoring. They will 
demonstrate that risk does not increase by documenting that parameters 
that impact the risk analysis do not change in a way that increases 
risk. Facilities will not be required to perform detailed risk analyses 
for public review, although the public will have an opportunity to 
comment on draft permit terms and conditions that reflect low risk 
demonstrations, and to judicially challenge final EPA approvals of 
eligibility demonstrations under CAA section 307(b)(1).
    We acknowledge the resource challenges faced by States, and, 
therefore, we will retain the authority to review and approve/
disapprove the low-risk subcategory eligibility demonstrations 
submitted by PCWP facilities.
    With regard to the title V permit programs being behind the 
statute's permit issuance deadlines, the incorporation of the NESHAP 
requirements is a necessary step that will require some resources. 
Inclusion of the low-risk subcategory delisting should be a 
straightforward part of the process and should not cause significant 
delay.

V. Statutory and Executive Order Reviews

A. Executive Order 12866: Regulatory Planning and Review

    Under Executive Order 12866 (58 FR 51735 (October 4, 1993)), the 
Agency must determine whether the regulatory action is ``significant'' 
and, therefore, subject to OMB review and the requirements of the 
Executive Order. The 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 obligation 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 the final rule is a ``significant regulatory action'' 
because the annual costs of complying with the final rule are expected 
to exceed $100 million. As such, this action was submitted to OMB for 
EO 12866 review. Changes made in response to OMB suggestions or 
recommendations are documented in the public record (see ADDRESSEES 
section of this preamble).
    We did not estimate health and welfare benefits associated with 
changes in emissions of HAP, CO, VOC, PM, NOX and 
SO2 for the final rule.

B. Paperwork Reduction Act

    The information collection requirements in the final rule have been 
submitted for approval to the OMB under the Paperwork Reduction Act, 44 
U.S.C. 3501 et seq. (ICR 1984.02) The information collection 
requirements are not enforceable until OMB approves them.
    The information requirements are based on notification, 
recordkeeping, and reporting requirements in the NESHAP General 
Provisions (40 CFR part 63, subpart A), which are mandatory for all 
operators subject to national emission standards. These recordkeeping 
and reporting requirements are specifically authorized by section 114 
of the CAA (42 U.S.C. 7414). All information submitted to the EPA 
pursuant to the recordkeeping and reporting requirements for which a 
claim of confidentiality is made is safeguarded according to Agency 
policies set forth in 40 CFR part 2, subpart B.
    Today's final rule will require maintenance inspections of the 
control devices but will not require any

[[Page 46006]]

notifications or reports beyond those required by the NESHAP General 
Provisions. The recordkeeping requirements require only the specific 
information needed to assure compliance.
    The annual monitoring, reporting, and recordkeeping burden for this 
collection (averaged over the first 3 years after the effective date of 
the rule) is estimated to be 4,692 labor hours per year, at a total 
annual cost of $250,528. This estimate includes notifications that 
facilities are subject to the rule; notifications of performance tests; 
notifications of compliance status, including the results of 
performance tests and other initial compliance demonstrations that do 
not include performance tests; SSM reports; semiannual compliance 
reports; and recordkeeping. In addition to the requirements of 40 CFR 
part 63, subpart A, facilities that wish to implement emissions 
averaging provisions must submit an EAP. Facilities may also submit a 
request for a routine control device maintenance exemption to justify 
the need for routine maintenance on the control device and to show how 
the facilities plan to minimize emissions to the greatest extent 
possible during the maintenance. The average number of respondents 
during the 3-year period after the effective date of the rule is 220, 
and the average number of responses estimated to be submitted is 197. 
The resulting estimated burden per response is 24 hours. Total capital/
startup costs associated with the testing, monitoring, reporting, and 
recordkeeping requirements over the 3-year period of the ICR are 
estimated to be $122,040, with operation and maintenance costs of 
$5,178.
    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. The OMB 
control numbers for the information collection requirements in the 
final rule will be listed in an amendment to 40 CFR part 9 in a 
subsequent Federal Register document after OMB approves the ICR.

C. Regulatory Flexibility Analysis

    The EPA has determined that it is not necessary to prepare a 
regulatory flexibility analysis in connection with this final rule. The 
EPA has also determined that the final rule will not have a significant 
economic impact on a substantial number of small entities.
    For purposes of assessing the impacts of today's final rule on 
small entities, small entity is defined as: (1) a small business 
ranging from 500 to 750 employees depending on the businesses NAICS 
code; (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 impact of today's final rule on 
small entities, EPA has concluded that this action will not have a 
significant economic impact on a substantial number of small entities. 
We have determined that, based on SBA size definitions for the affected 
industries and reported sales and employment data, 17 of the 52 
companies, or 32 percent, owning affected facilities are small 
businesses. Although small businesses represent 32 percent of the 
companies within the source category, they are expected to incur 8 
percent of the total industry compliance costs of $142 million. There 
are three small firms with compliance costs equal to or greater than 3 
percent of their sales. In addition, there are seven small firms with 
cost-to-sales ratios between 1 and 3 percent.
    We performed an economic impact analysis to estimate the changes in 
product price and production quantities for the firms affected by this 
rule. The analysis shows that of the 32 facilities owned by affected 
small firms, one small firm would be expected to shut down rather than 
incur the cost of compliance with the rule. Although any facility 
closure is cause for concern, it should be noted that the baseline 
economic condition of the facilities predicted to close affects the 
closure estimate provided by the economic model. Facilities which are 
already experiencing adverse economic conditions for reasons 
unconnected to this rule are more vulnerable to the impact of any new 
costs than those that are not.
    The analysis indicates that the final rule should not generate a 
significant economic impact on a substantial number of small entities 
for the PCWP manufacturing source category for the following reasons. 
First, of the ten small firms that have compliance costs greater than 1 
percent of sales, three small firms have compliance costs of greater 
than 3 percent of sales. Second, the results of the economic impact 
analysis show that one facility owned by a small firm out of the 32 
facilities owned by affected small firms may close due to the 
implementation of the final rule. The facility that may close rather 
than incur the cost of compliance appears to have low profitability 
levels currently. It also should be noted that the estimate of 
compliance costs for this facility is likely to be an overestimate due 
to the lack of facility-specific data available to assign a precise 
control cost in this case.
    Although the final rule will not have a significant economic impact 
on a substantial number of small entities, EPA nonetheless has tried to 
reduce the impact of the rule on small entities. First, we considered 
subcategorization based on production and throughput level to determine 
whether smaller process units would have a different MACT floor than 
larger process units. Our data show that subcategorization based on 
size would not result in a less stringent level of control for the 
smaller process units. Second, we chose to set the control requirements 
at the MACT floor control level and not at a control level more 
stringent. Thus, the control level specified in the final PCWP rule is 
the least stringent allowed by the CAA. Third, the final rule contains 
multiple compliance options to provide facilities with the flexibility 
to comply in the least costly manner while maintaining a workable and 
enforceable rule. The compliance options include emissions averaging 
and PBCO which allow inherently low-emitting process units to comply 
without installing add-on control devices and facilities to use 
innovative technology and P2 methods. Fourth, the final rule includes 
multiple test method options for measuring methanol, formaldehyde, and 
total HAP. Fifth, the final rule allows PCWP facilities to demonstrate 
eligibility for the delisted low-risk subcategory and thereby avoid 
MACT altogether. In addition, we worked with various trade associations 
during the development of the final rule.
    As discussed in earlier sections of this preamble, we present the 
impacts of the

[[Page 46007]]

rule associated with allowing PCWP facilities to demonstrate 
eligibility for the delisted low-risk subcategory and thereby avoid 
MACT altogether. The number of small businesses impacted is reduced to 
seven from the original 17, and the total number of businesses impacted 
is reduced to 42, down from the original 52. Small businesses represent 
17 percent of the companies within the source category, which is down 
from the 32 percent estimate for the final rule. These small businesses 
are expected to incur 4 percent of the total industry compliance costs 
of $74 million (the costs considering inclusion of the delisted low-
risk subcategory). There are no small firms with compliance costs equal 
to or greater than 3 percent of their sales as compared to three for 
the final rule. In addition, there are four small firms with cost-to-
sales ratios between 1 and 3 percent, which is down from seven for the 
final rule.

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 
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 regulatory proposals with significant 
Federal intergovernmental mandates, and informing, educating, and 
advising small governments on compliance with the regulatory 
requirements.
    Since the final rule is estimated to impose costs to the private 
sector in excess of $100 million per year, it is considered a 
significant regulatory action. Therefore, we have prepared the 
following statement with respect to sections 202 through 205 of the 
UMRA.
1. Statutory Authority
    This final rule establishes control requirements for existing and 
new PCWP sources pursuant to section 112 of the CAA. The CAA requires 
NESHAP to reflect the maximum degree of reduction in emissions of HAP 
that is achievable. This is commonly referred to as MACT. Section 
112(d)(3) of the CAA further defines a minimum level of control that 
can be considered for MACT standards, commonly referred to as the MACT 
floor, which for new sources is the level of control achieved by the 
best controlled similar source, and for existing sources is the level 
of control achieved by the average of the best performing 12 percent of 
sources in the category (or the best-performing five sources for 
categories with fewer than 30 sources).
    Control technologies and their performance are discussed in the 
background information document for this proposal (Docket numbers A-98-
44 and OAR-2003-0048). We considered emission reductions, costs, 
environmental impacts, and energy impacts in selecting the MACT 
standards. The final standards achieve sizable reductions in HAP and 
other pollutant emissions.
2. Social Costs and Benefits
    The regulatory analyses prepared for the final rule, including our 
assessment of costs and benefits, is detailed in the ``Regulatory 
Impact Analysis for the Plywood and Composite Wood Products NESHAP'' in 
Docket ID No. A-98-44. Based on estimated compliance costs associated 
with the final rule and the predicted change in prices and production 
in the affected industries, the estimated social costs of the final 
rule are $135.1 million (1999 dollars). The social costs of the final 
rule are the costs imposed upon society as a result of efforts toward 
compliance, and include the effects upon consumers of products made by 
the affected facilities.
    It is estimated that 3 years after implementation of the final 
rule, HAP would be reduced by 9,900 Mg/yr (11,000 tons/yr) due to 
reductions in formaldehyde, acetaldehyde, acrolein, methanol and other 
HAP from PCWP sources. Formaldehyde and acetaldehyde have been 
classified as ``probable human carcinogens.'' Acrolein, methanol and 
the other HAP are not considered carcinogenic, but produce several 
other toxic effects. The requirements of the final rule would also 
achieve reductions of 9,500 Mg/yr (10,000 tons/yr) of CO, approximately 
11,000 Mg/yr (12,000 tons/yr) of PM10, and approximately 25,000 Mg/yr 
(27,000 tons/yr) of VOC (approximated as THC). Exposure to CO can 
effect the cardiovascular system and the CNS. The PM emissions can 
result in fatalities and many respiratory problems (such as asthma or 
bronchitis). These estimates will be reduced to the extent facilities 
demonstrate eligibility to be included in the delisted low-risk 
subcategory. These estimated reductions occur from existing sources in 
operation 3 years after implementation of the requirements of the final 
rule and are expected to continue throughout the life of the sources. 
Human health effects associated with exposure to CO include 
cardiovascular system and CNS effects, which are directly related to 
reduced oxygen content of blood and which can result in modification of 
visual perception, hearing, motor and sensorimotor performance, 
vigilance, and cognitive ability. The VOC emissions reductions may lead 
to some reduction in ozone concentrations in areas in which the 
affected sources are located. There are both human health and welfare 
effects that result from exposure to ozone, and these effects are 
listed in Table 3 of this preamble.
    As mentioned earlier in this preamble, we are unable to provide a 
comprehensive quantification and monetization of the HAP-related 
benefits of the final rule. Nevertheless, it is possible to derive 
rough estimates for one of the more important benefit categories, i.e., 
the potential number of cancer cases avoided and cancer risk reduced as 
a result of the imposition of the MACT level of control on this source 
category. Our analysis suggests that imposition of the MACT level of 
control would reduce cancer cases by less than one case per year, on 
average, starting some years after implementation of the standards. We 
present these results in the RIA. This risk reduction estimate is 
uncertain and should be regarded as an extremely rough estimate and 
should be viewed in the context of the full spectrum of unquantified 
noncancer effects associated with the HAP reductions.

[[Page 46008]]

    At the present time, we cannot provide a monetary estimate for the 
benefits associated with the reductions in CO. We also did not provide 
a monetary estimate for the benefits associated with the changes in 
ozone concentrations that result from the VOC emissions reductions 
since we are unable to do the necessary air quality modeling to 
estimate the ozone concentration changes. For PM10, we did 
not provide a monetary estimate for the benefits associated with the 
reduction of these emissions, although these reductions are likely to 
have significant health benefits to populations living in the vicinity 
of affected sources.
    There may be increases in NOX emissions associated with 
today's final rule as a result of increased use of incineration-based 
controls. These NOX emission increases by themselves could 
cause some increase in ozone and PM concentrations, which could lead to 
impacts on human health and welfare as listed in Table 3 of this 
preamble. The potential impacts associated with increases in ambient PM 
and ozone due to these emission increases are discussed in the RIA. In 
addition to potential NOX increases at affected sources, 
today's final rule may also result in additional electricity use at 
affected sources due to application of controls. These potential 
increases in electricity use may increase emissions of SO2 
and NOX from electricity generating utilities. As such, the 
final rule may result in additional health impacts from increased 
ambient PM and ozone from these increased utility emissions. However, 
it is possible that the Acid Rain trading program may serve to keep 
SO2 emissions from increasing, and the NOX SIP 
call may serve to mitigate increases of NOX. We did not 
quantify or monetize these impacts.
    Every benefit-cost analysis examining the potential effects of a 
change in environmental protection requirements is limited to some 
extent by data gaps, limitations in model capabilities (such as 
geographic coverage), and uncertainties in the underlying scientific 
and economic studies used to configure the benefit and cost models. 
Deficiencies in the scientific literature often result in the inability 
to estimate changes in health and environmental effects, such as 
potential increases in premature mortality associated with increased 
exposure to CO. Deficiencies in the economics literature often result 
in the inability to assign economic values even to those health and 
environmental outcomes which can be quantified. These general 
uncertainties in the underlying scientific and economics literatures 
are discussed in detail in the RIA and its supporting documents and 
references.
3. Regulatory Alternatives Considered
    The final standards reflect the MACT floor, the least stringent 
regulatory alternative required under the CAA. In addition, the final 
rule includes the least burdensome and most flexible monitoring, 
reporting, and recordkeeping requirements that we feel will assure 
compliance with the compliance options and rule requirements. 
Therefore, the standards reflect the least costly, most cost-effective, 
and least burdensome regulatory option that achieves the objectives of 
the final rule.
4. Effects on the National Economy
    The economic impact analysis for the final rule estimates effects 
upon employment and foreign trade for the industries affected by the 
rule. The total reduction in employment for the affected industries is 
0.3 percent of the current employment level (or 225 employees). This 
estimate includes the increase in employment among firms in these 
industries that do not incur any cost associated with the final rule. 
There is also minimal change in the foreign trade behavior for the 
firms in these industries since the level of imports of affected 
composite wood products only increases by less than 0.1 percent. There 
will be reductions in effects on the national economy associated with 
eligibility of sources for the delisted low-risk subcategory. The 
employment level will now be reduced by 126 employees, which is 99 
fewer than the reduction estimated for the final rule. The increase in 
the level of imports is half as large as that for the final rule.
5. Consultation With Government Officials
    Throughout the development of the final rule, we interacted with 
representatives of affected State and local officials to inform them of 
the progress of our rulemaking efforts. We also consulted with 
representatives from other entities affected by the final rule, such as 
the American Forest & Paper Association, National Council for Air and 
Stream Improvement, APA-The Engineered Wood Association, Composite 
Panel Association, American Hardboard Association, Hardwood Plywood and 
Veneer Association, and representatives from affected companies.
    The number of small entities that are significantly affected by 
today's final PCWP standards is not expected to be substantial. The 
final rule contains no regulatory requirements that might significantly 
affect small governments because no PCWP facilities are owned by such 
governments. The full analysis of potential regulatory impacts on small 
organizations, small governments, and small businesses is included in 
the economic impact analysis in the docket and is listed at the 
beginning of today's action under SUPPLEMENTARY INFORMATION. Because 
the number of small entities that are likely to experience significant 
economic impacts as a result of today's final standards is not expected 
to be substantial, no plan to inform and advise small governments is 
required under 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'' is 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, the 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

[[Page 46009]]

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 final rule 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 final rule 
requirements will not supercede State regulations that are more 
stringent. Thus, the requirements of Executive Order 13132 do not apply 
to the final rule.

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'' is 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 final rule 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 plant sites are owned or operated by Indian tribal 
governments. Thus, Executive Order 13175 does not apply to the final 
rule.

G. Executive Order 13045: Protection of Children From Environmental 
Health & 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 an environmental 
health or safety risk that EPA has reason to feel may have a 
disproportionate effect on children. If the regulatory action meets 
both criteria, the EPA must evaluate the environmental 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 the Agency.
    The Agency does not have reason to feel that the environmental 
health or safety risks associated with the emissions addressed by 
today's final rule present a disproportionate risk to children. This 
demonstration is based on the fact that the noncancer human health 
values we used in our analysis (e.g., RfC) are determined to be 
protective of sensitive subpopulations, including children. Also, while 
the cancer human health values do not always expressly account for 
cancer effects in children, the cancer risks posed by PCWP facilities 
that meet the eligibility criteria for being included in the delisted 
low-risk subcategory will be sufficiently low so as not to be a concern 
for anyone in the population, including children.

H. Executive Order 13211: Actions That Significantly Affect Energy 
Supply, Distribution, or Use

    Executive Order 13211 (66 FR 28355, May 22, 2001) provides that 
agencies shall prepare and submit to the Administrator of the Office of 
Information and Regulatory Affairs, Office of Management and Budget, a 
Statement of Energy Effects for certain actions identified as 
``significant energy actions.'' Section 4(b) of Executive Order 13211 
defines ``significant energy actions'' as ``any action by an agency 
(normally published in the Federal Register) that promulgates or is 
expected to lead to the promulgation of a final rule or regulation, 
including notices of inquiry, advance notices of proposed rulemaking, 
and notices of proposed rulemaking: (1)(i) That is a significant 
regulatory action under Executive Order 12866 or any successor order, 
and (ii) is likely to have a significant adverse effect on the supply, 
distribution, or use of energy; or (2) that is designated by the 
Administrator of the Office of Information and Regulatory Affairs as a 
significant energy action.'' The final rule is not a ``significant 
energy action'' because it is not likely to have a significant adverse 
effect on the supply, distribution, or use of energy. The basis for the 
determination is as follows.
    The final rule affects manufacturers in the softwood veneer and 
plywood (NAICS 321212), reconstituted wood products (NAICS 321219), and 
engineered wood products (NAICS 321213) industries. There is no crude 
oil, fuel, or coal production from these industries. Hence, there is no 
direct effect on such energy production related to implementation of 
this proposal. In fact, as previously mentioned in this preamble, there 
will be an increase in energy consumption, and hence an increase in 
energy production, resulting from installation of RTO and WESP likely 
needed for sources to meet the requirements of the final rule. This 
increase in energy consumption is equal to 718 GWh/yr for electricity 
and 45 million m3/yr (1.6 billion ft3/yr) for 
natural gas. These increases are equivalent to 0.012 percent of 1998 
U.S. electricity production and 0.000001 percent of 1998 U.S. natural 
gas production.\9\ It should be noted, however, that the reduction in 
demand for product output from these industries may lead to a negative 
indirect effect on such energy production, for the output reduction 
will lead to less energy use by these industries and thus some 
reduction in overall energy production.
---------------------------------------------------------------------------

    \9\ U.S. Department of Energy, Energy Information 
Administration. Annual Energy Review, End-Use Energy Consumption for 
1998. Located on the Internet at http://www.eia.doe.gov/emeu/aer/enduse.html.
---------------------------------------------------------------------------

    For fuel production, the result of this indirect effect from 
reduced product output is a reduction of only about 1 barrel per day 
nationwide, or a 0.00001 percent reduction nationwide based on 1998 
U.S. fuel production data.\10\ For coal production, the resulting 
indirect effect from reduced product output is a reduction of only 
2,000 tons per year nationwide, or only a 0.00001 percent reduction 
nationwide based on 1998 U.S. coal production data. For electricity 
production, the resulting indirect effect from reduced product output 
is a reduction of 42.8 GWh/yr, or only a 0.00013 percent reduction 
nationwide based on 1998 U.S. electricity production data. Given that 
the estimated price increase for product output from any of the 
affected industries is no more than 2.5 percent, there should be no 
price increase for any energy type by more than this amount. The cost 
of energy distribution should not be affected by the final rule at all 
since the rule does not affect energy distribution facilities. Finally, 
with changes in net exports being a minimal percentage of domestic 
output (0.01 percent) from the affected industries, there will be only 
a negligible change in international trade, and hence in dependence on 
foreign energy supplies. No other adverse outcomes are expected to 
occur with regards to energy supplies. Thus, the net effect of the 
final rule on energy

[[Page 46010]]

production is an increase in electricity output of 0.012 percent 
compared to 1998 output data, and a negligible change in output of 
other energy types. All of the results presented above account for the 
passthrough of costs to consumers, as well as the cost impact to 
producers. These results also account for how energy use is related to 
product output for the affected industries.\11\ For more information on 
the estimated energy effects, please refer to the background memo \12\ 
to these calculations and the economic impact analysis for the final 
rule. The background memo and economic impact analysis are available in 
the public docket.
---------------------------------------------------------------------------

    \10\ Ibid.
    \11\ U.S. Department of Energy, Energy Information 
Administration. 1998 Manufacturing Energy Consumption Survey. 
Located on the Internet at http://www.eia.doe.gov/emeu/mecs/mecs98/datatables/contents.html.
    \12\ U.S. Environmental Protection Agency. ``Energy Impact 
Analysis of the Proposed Plywood and Composite Wood Products 
NESHAP.'' July 30, 2001.
---------------------------------------------------------------------------

    The impacts from consideration of a low-risk subcategory are a 
reduction in all of the energy impacts listed above. For fuel 
production, the result of this indirect effect from reduced product 
output is a reduction of only about 0.6 barrel per day nationwide, or a 
0.000007 percent reduction nationwide based on 1998 U.S. fuel 
production data.\13\ This is a 0.4 barrel smaller reduction than that 
estimated for the final rule. For coal production, the resulting 
indirect effect from reduced product output is a reduction of only 950 
tons per year nationwide, or only a 0.0000044 percent reduction 
nationwide based on 1998 U.S. coal production data. This is a smaller 
reduction than that estimated for the final rule by 1,050 tons per 
year. For electricity production, the resulting indirect effect from 
reduced product output is a reduction of 20.7 million kWh/yr, or only a 
0.00006 percent reduction nationwide based on 1998 U.S. electricity 
production data. This is a smaller output reduction than that estimated 
for the final rule by 22.1 million kWh/yr. Given that the estimated 
price increase for product output from any of the affected industries 
is no more than 2.5 percent, there should be no price increase for any 
energy type by more than this amount. The cost of energy distribution 
should not be affected by the final rule at all since the rule does not 
affect energy distribution facilities. Finally, with changes in net 
exports being a minimal percentage of domestic output (0.006 percent, 
or practically the same as that for the final rule) from the affected 
industries, there will be only a negligible change in international 
trade, and hence in dependence on foreign energy supplies. No other 
adverse outcomes are expected to occur with regards to energy supplies. 
Thus, the net effect on energy production if facilities are eligible 
for the low-risk source category is an increase in electricity output 
of 0.008 percent compared to 1998 output data, and a negligible change 
in output of other energy types. This is a 0.004 percent smaller 
increase in electricity output compared to the impact of the final 
rule. All of the results presented above account for the passthrough of 
costs to consumers, as well as the cost impact to producers. These 
results also account for how energy use is related to product output 
for the affected industries.\14\
---------------------------------------------------------------------------

    \13\ Ibid.
    \14\ U.S. Department of Energy, Energy Information 
Administration. 1998 Manufacturing Energy Consumption Survey. 
Located on the Internet at http://www.eia.doe.gov/emeu/mecs/mecs98/datatables/contents.html.
---------------------------------------------------------------------------

    Therefore, we conclude that the final rule is not likely to have a 
significant adverse effect on the supply, distribution, or use of 
energy.

I. National Technology Transfer and Advancement Act

    Section 12(d) of the National Technology Transfer and Advancement 
Act (NTTAA) of 1995 (Public Law No. 104-113; 15 U.S.C. 272 note) 
directs the EPA to use voluntary consensus standards in their 
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.
    The final rulemaking involves technical standards. The EPA cites 
the following standards in the final rule: EPA Methods 1, 1A, 2, 2A, 
2C, 2D, 2F, 2G, 3, 3A, 3B, 4, 18, 25A, and 29 in 40 CFR part 60, 
appendix A; 204 and 204A through F in 40 CFR part 51, appendix M; 308, 
316, and 320 in 40 CFR part 63, appendix A; EPA Method 0011 in EPA 
publication no. SW 846 (``Test Methods for Evaluating Solid Waste, 
Physical/Chemical Methods'') for formaldehyde; and two NCASI methods: 
NCASI Method CI/WP-98.01 (1998), ``Chilled Impinger Method For Use At 
Wood Products Mills to Measure Formaldehyde, Methanol, and Phenol,'' 
and NCASI Method IM/CAN/WP-99.02 (2003), ``Impinger/Canister Source 
Sampling Method For Selected HAPs and Other Compounds at Wood Products 
Facilities.''
    Consistent with the NTTAA, EPA conducted searches to identify 
voluntary consensus standards in addition to these EPA methods/
performance specifications. No applicable voluntary consensus standards 
were identified for EPA Methods 1A, 2A, 2D, 2F, 2G, 204, 204A through 
204F, 308, and 316. The search and review results have been documented 
and are placed in Docket numbers OAR-2003-0048 and A-98-44 for the 
final rule.
    One voluntary consensus standard was identified as an acceptable 
alternative to EPA test methods for the purposes of the final rule. The 
voluntary consensus standard ASTM D6348-03, ``Standard Test Method for 
Determination of Gaseous Compounds by Extractive Direct Interface 
Fourier Transform Infrared (FTIR) Spectroscopy,'' is an acceptable 
alternative to EPA Method 320 provided that the 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. Also, the moisture determination in 
ASTM D6348-03 is an acceptable alternative to the measurement of 
moisture using EPA Method 4.
    In addition to the voluntary consensus standards the EPA uses in 
the final rule, the search for emissions measurement procedures 
identified 13 other voluntary consensus standards. The EPA determined 
that 11 of those 13 voluntary consensus standards identified for 
measuring emissions of the HAP or surrogates subject to emission 
standards in the rule were impractical alternatives to EPA test methods 
for the purposes of the final rule. Therefore, EPA does not intend to 
adopt those standards for that purpose. (See Dockets A-44-98 and OAR-
2003-0048 for the reasons for the determination for the 11 methods.)
    Table 4 to subpart DDDD of 40 CFR part 63 lists the EPA testing 
methods included in the regulation. 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 of the EPA 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

[[Page 46011]]

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 a ``major rule'' as defined by 5 U.S.C. 
804(2). The final rule will be effective September 28, 2004.

List of Subjects

40 CFR Part 63

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

40 CFR Part 429

    Environmental protection, Forests and forest products, Furniture 
industry, Waste treatment and disposal, Water pollution control.

    Dated: February 26, 2004.
Michael O. Leavitt,
Administrator.

0
For the reasons stated in the preamble, title 40, chapter I, 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 et seq.

Subpart A--[Amended]

0
2. Section 63.14 is amended by adding paragraph (b)(54) and revising 
paragraph (f) to read as follows:


Sec.  63.14  Incorporation by reference.

* * * * *
    (b) * * *
    (54) ASTM D6348-03, Standard Test Method for Determination of 
Gaseous Compounds by Extractive Direct Interface Fourier Transform 
Infrared (FTIR) Spectroscopy, incorporation by reference (IBR) approved 
for Table 4 to Subpart DDDD of this part and Appendix B to subpart DDDD 
of this part as specified in the subpart.
* * * * *
    (f) The following material is available from the National Council 
of the Paper Industry for Air and Stream Improvement, Inc. (NCASI), 
P.O. Box 133318, Research Triangle Park, NC 27709-3318 or at http://www.ncasi.org.
    (1) NCASI Method DI/MEOH-94.02, Methanol in Process Liquids GC/FID 
(Gas Chromatography/Flame Ionization Detection), August 1998, Methods 
Manual, NCASI, Research Triangle Park, NC, IBR approved for Sec.  
63.457(c)(3)(ii) of subpart S of this part.
    (2) NCASI Method CI/WP-98.01, Chilled Impinger Method For Use At 
Wood Products Mills to Measure Formaldehyde, Methanol, and Phenol, 
1998, Methods Manual, NCASI, Research Triangle Park, NC, IBR approved 
for Table 4 to Subpart DDDD of this part.
    (3) NCASI Method IM/CAN/WP-99.02, Impinger/Canister Source Sampling 
Method For Selected HAPs and Other Compounds at Wood Products 
Facilities, January 2004, 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.
* * * * *

0
3. Part 63 is amended by adding subpart DDDD to read as follows:

Subpart DDDD--National Emission Standards for Hazardous Air 
Pollutants: Plywood and Composite Wood Products

Sec.

What This Subpart Covers

63.2230 What is the purpose of this subpart?
63.2231 Does this subpart apply to me?
63.2232 What parts of my plant does this subpart cover?
63.2233 When do I have to comply with this subpart?

Compliance Options, Operating Requirements, and Work Practice 
Requirements

63.2240 What are the compliance options and operating requirements 
and how must I meet them?
63.2241 What are the work practice requirements and how must I meet 
them?

General Compliance Requirements

63.2250 What are the general requirements?
63.2251 What are the requirements for the routine control device 
maintenance exemption?

Initial Compliance Requirements

63.2260 How do I demonstrate initial compliance with the compliance 
options, operating requirements, and work practice requirements?
63.2261 By what date must I conduct performance tests or other 
initial compliance demonstrations?
63.2262 How do I conduct performance tests and establish operating 
requirements?
63.2263 Initial compliance demonstration for a dry rotary dryer.
63.2264 Initial compliance demonstration for a hardwood veneer 
dryer.
63.2265 Initial compliance demonstration for a softwood veneer 
dryer.
63.2266 Initial compliance demonstration for a veneer redryer.
63.2267 Initial compliance demonstration for a reconstituted wood 
product press or board cooler.
63.2268 Initial compliance demonstration for a wet control device.
63.2269 What are my monitoring installation, operation, and 
maintenance requirements?

Continuous Compliance Requirements

63.2270 How do I monitor and collect data to demonstrate continuous 
compliance?
63.2271 How do I demonstrate continuous compliance with the 
compliance options, operating requirements, and work practice 
requirements?

Notifications, Reports, and Records

63.2280 What notifications must I submit and when?
63.2281 What reports must I submit and when?
63.2282 What records must I keep?
63.2283 In what form and how long must I keep my records?

Other Requirements and Information

63.2290 What parts of the General Provisions apply to me?
63.2291 Who implements and enforces this subpart?
63.2292 What definitions apply to this subpart?

Tables to Subpart DDDD of Part 63

Table 1A to Subpart DDDD of Part 63--Production-Based Compliance 
Options
Table 1B to Subpart DDDD of Part 63--Add-On Control Systems 
Compliance Options
Table 2 to Subpart DDDD of Part 63--Operating Requirements
Table 3 to Subpart DDDD of Part 63--Work Practice Requirements
Table 4 to Subpart DDDD of Part 63--Requirements for Performance 
Tests
Table 5 to Subpart DDDD of Part 63--Performance Testing and Initial 
Compliance Demonstrations for the Compliance Options and Operating 
Requirements
Table 6 to Subpart DDDD of Part 63--Initial Compliance 
Demonstrations for Work Practice Requirements
Table 7 to Subpart DDDD of Part 63--Continuous Compliance With the 
Compliance Options and Operating Requirements
Table 8 to Subpart DDDD of Part 63--Continuous Compliance With the 
Work Practice Requirements
Table 9 to Subpart DDDD of Part 63--Requirements for Reports
Table 10 to Subpart DDDD of Part 63--Applicability of General 
Provisions to Subpart DDDD

[[Page 46012]]

Appendix

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
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

What This Subpart Covers


Sec.  63.2230  What is the purpose of this subpart?

    This subpart establishes national compliance options, operating 
requirements, and work practice requirements for hazardous air 
pollutants (HAP) emitted from plywood and composite wood products 
(PCWP) manufacturing facilities. This subpart also establishes 
requirements to demonstrate initial and continuous compliance with the 
compliance options, operating requirements, and work practice 
requirements.


Sec.  63.2231  Does this subpart apply to me?

    This subpart applies to you if you meet the criteria in paragraphs 
(a) and (b) of this section, except for facilities that the 
Environmental Protection Agency (EPA) determines are part of the low-
risk subcategory of PCWP manufacturing facilities as specified in 
appendix B to this subpart.
    (a) You own or operate a PCWP manufacturing facility. A PCWP 
manufacturing facility is 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 structural panel or engineered wood 
product. 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, oriented 
strandboard, hardboard, fiberboard, medium density fiberboard, 
laminated strand lumber, laminated veneer lumber, wood I-joists, kiln-
dried lumber, and glue-laminated beams.
    (b) The PCWP manufacturing facility is located at a major source of 
HAP emissions. A major source of HAP emissions is any stationary source 
or group of stationary sources within a contiguous area and under 
common control that emits or has the potential to emit any single HAP 
at a rate of 9.07 megagrams (10 tons) or more per year or any 
combination of HAP at a rate of 22.68 megagrams (25 tons) or more per 
year.


Sec.  63.2232  What parts of my plant does this subpart cover?

    (a) This subpart applies to each new, reconstructed, or existing 
affected source at a PCWP manufacturing facility.
    (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, 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.
    (c) An affected source is a new affected source if you commenced 
construction of the affected source after January 9, 2003, and you meet 
the applicability criteria at the time you commenced construction.
    (d) An affected source is reconstructed if you meet the criteria as 
defined in Sec.  63.2.
    (e) An affected source is existing if it is not new or 
reconstructed.


Sec.  63.2233  When do I have to comply with this subpart?

    (a) If you have a new or reconstructed affected source, you must 
comply with this subpart according to paragraph (a)(1) or (2) of this 
section, whichever is applicable.
    (1) If the initial startup of your affected source is before 
September 28, 2004, then you must comply with the compliance options, 
operating requirements, and work practice requirements for new and 
reconstructed sources in this subpart no later than September 28, 2004.
    (2) If the initial startup of your affected source is after 
September 28, 2004, then you must comply with the compliance options, 
operating requirements, and work practice requirements for new and 
reconstructed sources in this subpart upon initial startup of your 
affected source.
    (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, 2007.
    (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, 2007 or upon initial 
startup of your affected source as a major source, whichever is later.
    (d) You must meet the notification requirements according to the 
schedule in Sec.  63.2280 and according to 40 CFR part 63, subpart A. 
Some of the notifications must be submitted before you are required to 
comply with the compliance options, operating requirements, and work 
practice requirements in this subpart.

Compliance Options, Operating Requirements, and Work Practice 
Requirements


Sec.  63.2240  What are the compliance options and operating 
requirements and how must I meet them?

    You must meet the compliance options and operating requirements 
described in Tables 1A, 1B, and 2 to this subpart and in paragraph (c) 
of this section by using one or more of the compliance options listed 
in paragraphs (a), (b), and (c) of this section. The process units 
subject to the compliance options are listed in Tables 1A and 1B to 
this subpart and are defined in Sec.  63.2292. You need only to meet 
one of the compliance options outlined in paragraphs (a) through (c) of 
this section for each process unit. You cannot combine compliance 
options in paragraph (a), (b), or (c) for a single process unit. (For 
example, you cannot use a production-based compliance option in 
paragraph (a) for one vent of a veneer dryer and an add-on control 
system compliance option in paragraph (b) for another vent on the same 
veneer dryer. You must use either the production-based compliance 
option or an add-on control system compliance option for the entire 
dryer.)
    (a) Production-based compliance options. You must meet the 
production-based total HAP compliance options in Table 1A to this 
subpart and the applicable operating requirements in Table 2 to this 
subpart. You may not use an add-on control system or wet control

[[Page 46013]]

device to meet the production-based compliance options.
    (b) Compliance options for add-on control systems. You must use an 
emissions control system and demonstrate that the resulting emissions 
meet the compliance options and operating requirements in Tables 1B and 
2 to this subpart. If you own or operate a reconstituted wood product 
press at a new or existing affected source or a reconstituted wood 
product board cooler at a new affected source, and you choose to comply 
with one of the concentration-based compliance options for a control 
system outlet (presented as option numbers 2, 4, and 6 in Table 1B to 
this subpart), you must have a capture device that either meets the 
definition of wood products enclosure in Sec.  63.2292 or achieves a 
capture efficiency of greater than or equal to 95 percent.
    (c) Emissions averaging compliance option (for existing sources 
only). Using the procedures in paragraphs (c)(1) through (3) of this 
section, you must demonstrate that emissions included in the emissions 
average meet the compliance options and operating requirements. New 
sources may not use emissions averaging to comply with this subpart.
    (1) Calculation of required and actual mass removal. Limit 
emissions of total HAP, as defined in Sec.  63.2292, to include 
acetaldehyde, acrolein, formaldehyde, methanol, phenol, and 
propionaldehyde from your affected source to the standard specified by 
Equations 1, 2, and 3 of this section.
[GRAPHIC] [TIFF OMITTED] TR72AD04.000

[GRAPHIC] [TIFF OMITTED] TR72AD04.001

[GRAPHIC] [TIFF OMITTED] TR72AD04.002


Where:

RMR = required mass removal of total HAP from all process units 
generating debits (i.e., all process units that are subject to the 
compliance options in Tables 1A and 1B to this subpart and that are 
either uncontrolled or under-controlled), pounds per semiannual period;
AMR = actual mass removal of total HAP from all process units 
generating credits (i.e., all process units that are controlled as part 
of the Emissions Averaging Plan including credits from debit-generating 
process units that are under-controlled), pounds per semiannual period;
UCEPi = mass of total HAP from an uncontrolled or under-
controlled process unit (i) that generates debits, pounds per hour;
OHi = number of hours a process unit (i) is operated during 
the semiannual period, hours per 6-month period;
CDi = control system efficiency for the emission point (i) 
for total HAP, expressed as a fraction, and not to exceed 90 percent, 
unitless (Note: To calculate the control system efficiency of 
biological treatment units that do not meet the definition of biofilter 
in Sec.  63.2292, you must use 40 CFR part 63, appendix C, 
Determination of the Fraction Biodegraded (Fbio) in a 
Biological Treatment Unit.);
OCEPi = mass of total HAP from a process unit (i) that 
generates credits (including credits from debit-generating process 
units that are under-controlled), pounds per hour;
0.90 = required control system efficiency of 90 percent multiplied, 
unitless.

    (2) Requirements for debits and credits. You must calculate debits 
and credits as specified in paragraphs (c)(2)(i) through (vi) of this 
section.
    (i) You must limit process units in the emissions average to those 
process units located at the existing affected source as defined in 
Sec.  63.2292.
    (ii) You cannot use nonoperating process units to generate 
emissions averaging credits. You cannot use process units that are shut 
down to generate emissions averaging debits or credits.
    (iii) You may not include in your emissions average process units 
controlled to comply with a State, Tribal, or Federal rule other than 
this subpart.
    (iv) You must use actual measurements of total HAP emissions from 
process units to calculate your required mass removal (RMR) and actual 
mass removal (AMR). The total HAP measurements must be obtained 
according to Sec.  63.2262(b) through (d), (g), and (h), using the 
methods specified in Table 4 to this subpart.
    (v) Your initial demonstration that the credit-generating process 
units will be capable of generating enough credits to offset the debits 
from the debit-generating process units must be made under 
representative operating conditions. After the compliance date, you 
must use actual operating data for all debit and credit calculations.
    (vi) Do not include emissions from the following time periods in 
your emissions averaging calculations:
    (A) Emissions during periods of startup, shutdown, and malfunction 
as described in the startup, shutdown, and malfunction plan (SSMP).
    (B) Emissions during periods of monitoring malfunctions, associated 
repairs, and required quality assurance or control activities or during 
periods of control device maintenance covered in your routine control 
device maintenance exemption. No credits may be assigned to credit-
generating process units, and maximum debits must be assigned to debit-
generating process units during these periods.
    (3) Operating requirements. You must meet the operating 
requirements in Table 2 to this subpart for each process unit or 
control device used in calculation of emissions averaging credits.


Sec.  63.2241  What are the work practice requirements and how must I 
meet them?

    (a) You must meet each work practice requirement in Table 3 to this 
subpart that applies to you.
    (b) As provided in Sec.  63.6(g), we, the EPA, may choose to grant 
you permission to use an alternative to the work practice requirements 
in this section.
    (c) If you have a dry rotary dryer, you may choose to designate 
your dry rotary dryer as a green rotary dryer and meet the more 
stringent compliance options and operating requirements in Sec.  
63.2240 for green rotary dryers instead of the work practices for dry 
rotary dryers. If you have a hardwood veneer dryer or veneer redryer, 
you may choose to designate your hardwood veneer dryer or veneer 
redryer as a softwood veneer dryer and meet the more stringent 
compliance options and operating requirements in Sec.  63.2240 for 
softwood veneer dryer heated zones instead of the work practices for 
hardwood veneer dryers or veneer redryers.

General Compliance Requirements


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

[[Page 46014]]

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 scheduled 
startup and shutdown periods, and during malfunctions. These startup 
and shutdown periods must not exceed the minimum amount of time 
necessary for these events.
    (b) You must always operate and maintain your affected source, 
including air pollution control and monitoring equipment, according to 
the provisions in Sec.  63.6(e)(1)(i).
    (c) You must develop and implement a written SSMP according to the 
provisions in Sec.  63.6(e)(3).
    (d) Shutoff of direct-fired burners resulting from partial and full 
production stoppages of direct-fired softwood veneer dryers or over-
temperature events shall be deemed shutdowns and not malfunctions. 
Lighting or re-lighting any one or all gas burners in direct-fired 
softwood veneer dryers shall be deemed startups and not malfunctions.


Sec.  63.2251  What are the requirements for the routine control device 
maintenance exemption?

    (a) You may request a routine control device maintenance exemption 
from the EPA Administrator for routine maintenance events such as 
control device bakeouts, washouts, media replacement, and replacement 
of corroded parts. Your request must justify the need for the routine 
maintenance on the control device and the time required to accomplish 
the maintenance activities, describe the maintenance activities and the 
frequency of the maintenance activities, explain why the maintenance 
cannot be accomplished during process shutdowns, describe how you plan 
to make reasonable efforts to minimize emissions during the 
maintenance, and provide any other documentation required by the EPA 
Administrator.
    (b) The routine control device maintenance exemption must not 
exceed the percentages of process unit operating uptime in paragraphs 
(b)(1) and (2) of this section.
    (1) If the control device is used to control a green rotary dryer, 
tube dryer, rotary strand dryer, or pressurized refiner, then the 
routine control device maintenance exemption must not exceed 3 percent 
of annual operating uptime for each process unit controlled.
    (2) If the control device is used to control a softwood veneer 
dryer, reconstituted wood product press, reconstituted wood product 
board cooler, hardboard oven, press predryer, conveyor strand dryer, or 
fiberboard mat dryer, then the routine control device maintenance 
exemption must not exceed 0.5 percent of annual operating uptime for 
each process unit controlled.
    (3) If the control device is used to control a combination of 
equipment listed in both paragraphs (b)(1) and (2) of this section, 
such as a tube dryer and a reconstituted wood product press, then the 
routine control device maintenance exemption must not exceed 3 percent 
of annual operating uptime for each process unit controlled.
    (c) The request for the routine control device maintenance 
exemption, if approved by the EPA Administrator, must be IBR in and 
attached to the affected source's title V permit.
    (d) The compliance options and operating requirements do not apply 
during times when control device maintenance covered under your 
approved routine control device maintenance exemption is performed. You 
must minimize emissions to the greatest extent possible during these 
routine control device maintenance periods.
    (e) To the extent practical, startup and shutdown of emission 
control systems must be scheduled during times when process equipment 
is also shut down.

Initial Compliance Requirements


Sec.  63.2260  How do I demonstrate initial compliance with the 
compliance options, operating requirements, and work practice 
requirements?

    (a) To demonstrate initial compliance with the compliance options 
and operating requirements, you must conduct performance tests and 
establish each site-specific operating requirement in Table 2 to this 
subpart according to the requirements in Sec.  63.2262 and Table 4 to 
this subpart. Combustion units that accept process exhausts into the 
flame zone are exempt from the initial performance testing and 
operating requirements for thermal oxidizers.
    (b) You must demonstrate initial compliance with each compliance 
option, operating requirement, and work practice requirement that 
applies to you according to Tables 5 and 6 to this subpart and 
according to Sec. Sec.  63.2260 through 63.2269 of this subpart.
    (c) You must submit the Notification of Compliance Status 
containing the results of the initial compliance demonstration 
according to the requirements in Sec.  63.2280(d).


Sec.  63.2261  By what date must I conduct performance tests or other 
initial compliance demonstrations?

    (a) You must conduct performance tests upon initial startup or no 
later than 180 calendar days after the compliance date that is 
specified for your source in Sec.  63.2233 and according to Sec.  
63.7(a)(2), whichever is later.
    (b) You must conduct initial compliance demonstrations that do not 
require performance tests upon initial startup or no later than 30 
calendar days after the compliance date that is specified for your 
source in Sec.  63.2233, whichever is later.


Sec.  63.2262  How do I conduct performance tests and establish 
operating requirements?

    (a) You must conduct each performance test according to the 
requirements in Sec.  63.7(e)(1), the requirements in paragraphs (b) 
through (o) of this section, and according to the methods specified in 
Table 4 to this subpart.
    (b) Periods when performance tests must be conducted. (1) You must 
not conduct performance tests during periods of startup, shutdown, or 
malfunction, as specified in Sec.  63.7(e)(1).
    (2) You must test under representative operating conditions as 
defined in Sec.  63.2292. You must describe representative operating 
conditions in your performance test report for the process and control 
systems and explain why they are representative.
    (c) Number of test runs. You must conduct three separate test runs 
for each performance test required in this section as specified in 
Sec.  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 of 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 this subpart, which requires a minimum of three separate runs of 
at least 20 minutes each.
    (d) Location of sampling sites. (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 and prior to any releases to the atmosphere. For HAP-
altering controls in sequence, such as a wet control device followed by 
a thermal oxidizer, sampling sites must be located at the functional 
inlet of the control sequence (e.g., prior to the wet control device) 
and at the outlet of the control sequence (e.g., thermal oxidizer

[[Page 46015]]

outlet) and prior to any releases to the atmosphere.
    (2) Sampling sites for process units meeting compliance options 
without a control device must be located prior to any releases to the 
atmosphere. Facilities demonstrating compliance with a production-based 
compliance option for a process unit equipped with a wet control device 
must locate sampling sites prior to the wet control device.
    (e) Collection of monitoring data. You must collect operating 
parameter monitoring system or continuous emissions monitoring system 
(CEMS) data at least every 15 minutes during the entire performance 
test and determine the parameter or concentration value for the 
operating requirement during the performance test using the methods 
specified in paragraphs (k) through (o) of this section.
    (f) Collection of production data. To comply with any of the 
production-based compliance options, you must measure and record the 
process unit throughput during each performance test.
    (g) Nondetect data. (1) Except as specified in paragraph (g)(2) of 
this section, all nondetect data (Sec.  63.2292) must be treated as 
one-half of the method detection limit when determining total HAP, 
formaldehyde, methanol, or total hydrocarbon (THC) emission rates.
    (2) When showing compliance with the production-based compliance 
options in Table 1A to this subpart, you may treat emissions of an 
individual HAP as zero if all three of the performance test runs result 
in a nondetect measurement, and the method detection limit is less than 
or equal to 1 parts per million by volume, dry basis (ppmvd). 
Otherwise, nondetect data for individual HAP must be treated as one-
half of the method detection limit.
    (h) Calculation of percent reduction across a control system. When 
determining the control system efficiency for any control system 
included in your emissions averaging plan (not to exceed 90 percent) 
and when complying with any of the compliance options based on percent 
reduction across a control system in Table 1B to this subpart, as part 
of the performance test, you must calculate the percent reduction using 
Equation 1 of this section:
[GRAPHIC] [TIFF OMITTED] TR72AD04.003


Where:

PR = percent reduction, percent;
CE = capture efficiency, percent (determined for reconstituted wood 
product presses and board coolers as required in Table 4 to this 
subpart);
ERin = emission rate of total HAP (calculated as the sum of 
the emission rates of acetaldehyde, acrolein, formaldehyde, methanol, 
phenol, and propionaldehyde), THC, formaldehyde, or methanol in the 
inlet vent stream of the control device, pounds per hour;
ERout = emission rate of total HAP (calculated as the sum of 
the emission rates of acetaldehyde, acrolein, formaldehyde, methanol, 
phenol, and propionaldehyde), THC, formaldehyde, or methanol in the 
outlet vent stream of the control device, pounds per hour.

    (i) Calculation of mass per unit production. To comply with any of 
the production-based compliance options in Table 1A to this subpart, 
you must calculate your mass per unit production emissions for each 
performance test run using Equation 2 of this section:
[GRAPHIC] [TIFF OMITTED] TR72AD04.004


Where:

MP = mass per unit production, pounds per oven dried ton OR pounds per 
thousand square feet on a specified thickness basis (see paragraph (j) 
of this section if you need to convert from one thickness basis to 
another);
ERHAP = emission rate of total HAP (calculated as the sum of 
the emission rates of acetaldehyde, acrolein, formaldehyde, methanol, 
phenol, and propionaldehyde) in the stack, pounds per hour;
P = process unit production rate (throughput), oven dried tons per hour 
OR thousand square feet per hour on a specified thickness basis;
CE = capture efficiency, percent (determined for reconstituted wood 
product presses and board coolers as required in Table 4 to this 
subpart).

    (j) Thickness basis conversion. Use Equation 3 of this section to 
convert from one thickness basis to another:
[GRAPHIC] [TIFF OMITTED] TR72AD04.005


Where:

MSFA = thousand square feet on an A-inch basis;
MSFB = thousand square feet on a B-inch basis;
A = old thickness you are converting from, inches;
B = new thickness you are converting to, inches.

    (k) Establishing thermal oxidizer operating requirements. If you 
operate a thermal oxidizer, you must establish your thermal oxidizer 
operating parameters according to paragraphs (k)(1) through (3) of this 
section.
    (1) During the performance test, you must continuously monitor the 
firebox temperature during each of the required 1-hour test runs. For 
regenerative thermal oxidizers, you may measure the temperature in 
multiple locations (e.g., one location per burner) in the combustion 
chamber and calculate the average of the temperature measurements prior 
to reducing the temperature data to 15-minute averages for purposes of 
establishing your minimum firebox temperature. The minimum firebox 
temperature must then be established as the average of the three 
minimum 15-minute firebox temperatures monitored during the three test 
runs. Multiple three-run performance tests may be conducted to 
establish a range of parameter values under different operating 
conditions.
    (2) You may establish a different minimum firebox temperature for 
your thermal oxidizer by submitting the notification specified in Sec.  
63.2280(g) and conducting a repeat performance test as specified in 
paragraph (k)(1) of this section that demonstrates compliance with the 
applicable compliance options of this subpart.
    (3) If your thermal oxidizer is a combustion unit that accepts 
process exhaust into the flame zone, then you are exempt from the 
performance testing and monitoring requirements specified in paragraphs 
(k)(1) and (2) of this section. To demonstrate initial compliance, you 
must submit documentation with your Notification of Compliance Status 
showing that process exhausts controlled by the combustion unit enter 
into the flame zone.
    (l) Establishing catalytic oxidizer operating requirements. If you 
operate a catalytic oxidizer, you must establish your catalytic 
oxidizer operating parameters according to paragraphs (l)(1) and (2) of 
this section.
    (1) During the performance test, you must continuously monitor 
during the required 1-hour test runs either the temperature at the 
inlet to each catalyst bed or the temperature in the combustion 
chamber. For regenerative catalytic oxidizers, you must calculate the 
average of the temperature measurements from each catalyst bed inlet or 
within the combustion chamber prior to reducing the temperature data to 
15-minute averages for purposes of

[[Page 46016]]

establishing your minimum catalytic oxidizer temperature. The minimum 
catalytic oxidizer temperature must then be established as the average 
of the three minimum 15-minute temperatures monitored during the three 
test runs. Multiple three-run performance tests may be conducted to 
establish a range of parameter values under different operating 
conditions.
    (2) You may establish a different minimum catalytic oxidizer 
temperature by submitting the notification specified in Sec.  
63.2280(g) and conducting a repeat performance test as specified in 
paragraphs (l)(1) and (2) of this section that demonstrates compliance 
with the applicable compliance options of this subpart.
    (m) Establishing biofilter operating requirements. If you operate a 
biofilter, you must establish your biofilter operating requirements 
according to paragraphs (m)(1) through (3) of this section.
    (1) During the performance test, you must continuously monitor the 
biofilter bed temperature during each of the required 1-hour test runs. 
To monitor biofilter bed temperature, you may use multiple 
thermocouples in representative locations throughout the biofilter bed 
and calculate the average biofilter bed temperature across these 
thermocouples prior to reducing the temperature data to 15-minute 
averages for purposes of establishing biofilter bed temperature limits. 
The biofilter bed temperature range must be established as the minimum 
and maximum 15-minute biofilter bed temperatures monitored during the 
three test runs. You may base your biofilter bed temperature range on 
values recorded during previous performance tests provided that the 
data used to establish the temperature ranges have been obtained using 
the test methods required in this subpart. If you use data from 
previous performance tests, you must certify that the biofilter and 
associated process unit(s) have not been modified subsequent to the 
date of the performance tests. Replacement of the biofilter media with 
the same type of material is not considered a modification of the 
biofilter for purposes of this section.
    (2) For a new biofilter installation, you will be allowed up to 180 
days following the compliance date or 180 days following initial 
startup of the biofilter to complete the requirements in paragraph 
(m)(1) of this section.
    (3) You may expand your biofilter bed temperature operating range 
by submitting the notification specified in Sec.  63.2280(g) and 
conducting a repeat performance test as specified in paragraph (m)(1) 
of this section that demonstrates compliance with the applicable 
compliance options of this subpart.
    (n) Establishing operating requirements for process units meeting 
compliance options without a control device. If you operate a process 
unit that meets a compliance option in Table 1A to this subpart, or is 
a process unit that generates debits in an emissions average without 
the use of a control device, you must establish your process unit 
operating parameters according to paragraphs (n)(1) through (2) of this 
section.
    (1) During the performance test, you must identify and document the 
process unit controlling parameter(s) that affect total HAP emissions 
during the three-run performance test. The controlling parameters you 
identify must coincide with the representative operating conditions you 
describe according to Sec.  63.2262(b)(2). For each parameter, you must 
specify appropriate monitoring methods, monitoring frequencies, and for 
continuously monitored parameters, averaging times not to exceed 24 
hours. The operating limit for each controlling parameter must then be 
established as the minimum, maximum, range, or average (as appropriate 
depending on the parameter) recorded during the performance test. 
Multiple three-run performance tests may be conducted to establish a 
range of parameter values under different operating conditions.
    (2) You may establish different controlling parameter limits for 
your process unit by submitting the notification specified in Sec.  
63.2280(g) and conducting a repeat performance test as specified in 
paragraph (n)(1) of this section that demonstrates compliance with the 
compliance options in Table 1A to this subpart or is used to establish 
emission averaging debits for an uncontrolled process unit.
    (o) Establishing operating requirements using THC CEMS. If you 
choose to meet the operating requirements by monitoring THC 
concentration instead of monitoring control device or process operating 
parameters, you must establish your THC concentration operating 
requirement according to paragraphs (o)(1) through (2) of this section.
    (1) During the performance test, you must continuously monitor THC 
concentration using your CEMS during each of the required 1-hour test 
runs. The maximum THC concentration must then be established as the 
average of the three maximum 15-minute THC concentrations monitored 
during the three test runs. Multiple three-run performance tests may be 
conducted to establish a range of THC concentration values under 
different operating conditions.
    (2) You may establish a different maximum THC concentration by 
submitting the notification specified in Sec.  63.2280(g) and 
conducting a repeat performance test as specified in paragraph (o)(1) 
of this section that demonstrates compliance with the compliance 
options in Tables 1A and 1B to this subpart.


Sec.  63.2263  Initial compliance demonstration for a dry rotary dryer.

    If you operate a dry rotary dryer, you must demonstrate that your 
dryer processes furnish with an inlet moisture content of less than or 
equal to 30 percent (by weight, dry basis) and operates with a dryer 
inlet temperature of less than or equal to 600[deg]F. You must 
designate and clearly identify each dry rotary dryer. You must record 
the inlet furnish moisture content (dry basis) and inlet dryer 
operating temperature according to Sec.  63.2269(a), (b), and (c) and 
Sec.  63.2270 for a minimum of 30 calendar days. You must submit the 
highest recorded 24-hour average inlet furnish moisture content and the 
highest recorded 24-hour average dryer inlet temperature with your 
Notification of Compliance Status. In addition, you must submit with 
the Notification of Compliance Status a signed statement by a 
responsible official that certifies with truth, accuracy, and 
completeness that the dry rotary dryer will dry furnish with a maximum 
inlet moisture content less than or equal to 30 percent (by weight, dry 
basis) and will operate with a maximum inlet temperature of less than 
or equal to 600[deg]F in the future.


Sec.  63.2264  Initial compliance demonstration for a hardwood veneer 
dryer.

    If you operate a hardwood veneer dryer, you must record the annual 
volume percentage of softwood veneer species processed in the dryer as 
follows:
    (a) Use Equation 1 of this section to calculate the annual volume 
percentage of softwood species dried:
[GRAPHIC] [TIFF OMITTED] TR72AD04.006

Where:

SW[percnt] = annual volume percent softwood species dried;
SW = softwood veneer dried during the previous 12 months, thousand 
square feet (\3/8\-inch basis);

T = total softwood and hardwood veneer dried during the previous 12 
months, thousand square feet (\3/8\-inch basis).


[[Page 46017]]


    (b) You must designate and clearly identify each hardwood veneer 
dryer. Submit with the Notification of Compliance Status the annual 
volume percentage of softwood species dried in the dryer based on your 
dryer production for the 12 months prior to the compliance date 
specified for your source in Sec.  63.2233. If you did not dry any 
softwood species in the dryer during the 12 months prior to the 
compliance date, then you need only to submit a statement indicating 
that no softwood species were dried. In addition, submit with the 
Notification of Compliance Status a signed statement by a responsible 
official that certifies with truth, accuracy, and completeness that the 
veneer dryer will be used to process less than 30 volume percent 
softwood species in the future.


Sec.  63.2265  Initial compliance demonstration for a softwood veneer 
dryer.

    If you operate a softwood veneer dryer, you must develop a plan for 
review and approval for minimizing fugitive emissions from the veneer 
dryer heated zones, and you must submit the plan with your Notification 
of Compliance Status.


Sec.  63.2266  Initial compliance demonstration for a veneer redryer.

    If you operate a veneer redryer, you must record the inlet moisture 
content of the veneer processed in the redryer according to Sec.  
63.2269(a) and (c) and Sec.  63.2270 for a minimum of 30 calendar days. 
You must designate and clearly identify each veneer redryer. You must 
submit the highest recorded 24-hour average inlet veneer moisture 
content with your Notification of Compliance Status to show that your 
veneer redryer processes veneer with an inlet moisture content of less 
than or equal to 25 percent (by weight, dry basis). In addition, submit 
with the Notification of Compliance Status a signed statement by a 
responsible official that certifies with truth, accuracy, and 
completeness that the veneer redryer will dry veneer with a moisture 
content less than 25 percent (by weight, dry basis) in the future.


Sec.  63.2267  Initial compliance demonstration for a reconstituted 
wood product press or board cooler.

    If you operate a reconstituted wood product press at a new or 
existing affected source or a reconstituted wood product board cooler 
at a new affected source, then you must either use a wood products 
enclosure as defined in Sec.  63.2292 or measure the capture efficiency 
of the capture device for the press or board cooler using Methods 204 
and 204A through 204F of 40 CFR part 51, appendix M (as appropriate), 
or using the alternative tracer gas method contained in appendix A to 
this subpart. You must submit documentation that the wood products 
enclosure meets the press enclosure design criteria in Sec.  63.2292 or 
the results of the capture efficiency verification with your 
Notification of Compliance Status.


Sec.  63.2268  Initial compliance demonstration for a wet control 
device.

    If you use a wet control device as the sole means of reducing HAP 
emissions, you must develop and implement a plan for review and 
approval to address how organic HAP captured in the wastewater from the 
wet control device is contained or destroyed to minimize re-release to 
the atmosphere such that the desired emissions reductions are obtained. 
You must submit the plan with your Notification of Compliance Status.


Sec.  63.2269  What are my monitoring installation, operation, and 
maintenance requirements?

    (a) General continuous parameter monitoring requirements. You must 
install, operate, and maintain each continuous parameter monitoring 
system (CPMS) according to paragraphs (a)(1) through (3) of this 
section.
    (1) The CPMS must be capable of completing a minimum of one cycle 
of operation (sampling, analyzing, and recording) for each successive 
15-minute period.
    (2) At all times, you must maintain the monitoring equipment 
including, but not limited to, maintaining necessary parts for routine 
repairs of the monitoring equipment.
    (3) Record the results of each inspection, calibration, and 
validation check.
    (b) Temperature monitoring. For each temperature monitoring device, 
you must meet the requirements in paragraphs (a) and (b)(1) through (6) 
of this section.
    (1) Locate the temperature sensor in a position that provides a 
representative temperature.
    (2) Use a temperature sensor with a minimum accuracy of 4[deg]F or 
0.75 percent of the temperature value, whichever is larger.
    (3) If a chart recorder is used, it must have a sensitivity with 
minor divisions not more than 20[deg]F.
    (4) Perform an electronic calibration at least semiannually 
according to the procedures in the manufacturer's owners manual. 
Following the electronic calibration, you must conduct a temperature 
sensor validation check in which a second or redundant temperature 
sensor placed nearby the process temperature sensor must yield a 
reading within 30[deg]F of the process temperature sensor's reading.
    (5) Conduct calibration and validation checks any time the sensor 
exceeds the manufacturer's specified maximum operating temperature 
range or install a new temperature sensor.
    (6) At least quarterly, inspect all components for integrity and 
all electrical connections for continuity, oxidation, and galvanic 
corrosion.
    (c) Wood moisture monitoring. For each furnish or veneer moisture 
meter, you must meet the requirements in paragraphs (a)(1), (2), (4) 
and (5) and paragraphs (c)(1) through (4) of this section.
    (1) For dry rotary dryers, use a continuous moisture monitor with a 
minimum accuracy of 1 percent (dry basis) moisture or better in the 25 
to 35 percent (dry basis) moisture content range. For veneer redryers, 
use a continuous moisture monitor with a minimum accuracy of 3 percent 
(dry basis) moisture or better in the 15 to 25 percent (dry basis) 
moisture content range. Alternatively, you may use a continuous 
moisture monitor with a minimum accuracy of 5 percent (dry basis) 
moisture or better for dry rotary dryers used to dry furnish with less 
than 25 percent (dry basis) moisture or for veneer redryers used to 
redry veneer with less than 20 percent (dry basis) moisture.
    (2) Locate the moisture monitor in a position that provides a 
representative measure of furnish or veneer moisture.
    (3) Calibrate the moisture monitor based on the procedures 
specified by the moisture monitor manufacturer at least once per 
semiannual compliance period (or more frequently if recommended by the 
moisture monitor manufacturer).
    (4) At least quarterly, inspect all components of the moisture 
monitor for integrity and all electrical connections for continuity.
    (5) Use Equation 1 of this section to convert percent moisture 
measurements wet basis to a dry basis:
[GRAPHIC] [TIFF OMITTED] TR72AD04.012

Where:

MCdry = percent moisture content of wood material (weight 
percent, dry basis);
MCwet = percent moisture content of wood material (weight 
percent, wet basis).

    (d) Continuous emission monitoring system(s). Each CEMS must be 
installed, operated, and maintained according to

[[Page 46018]]

paragraphs (d)(1) through (4) of this section.
    (1) Each CEMS for monitoring THC concentration must be installed, 
operated, and maintained according to Performance Specification 8 of 40 
CFR part 60, appendix B. You must also comply with Procedure 1 of 40 
CFR part 60, appendix F.
    (2) You must conduct a performance evaluation of each CEMS 
according to the requirements in Sec.  63.8 and according to 
Performance Specification 8 of 40 CFR part 60, appendix B.
    (3) As specified in Sec.  63.8(c)(4)(ii), each CEMS must complete a 
minimum of one cycle of operation (sampling, analyzing, and data 
recording) for each successive 15-minute period.
    (4) The CEMS data must be reduced as specified in Sec.  63.8(g)(2) 
and Sec.  63.2270(d) and (e).

Continuous Compliance Requirements


Sec.  63.2270  How do I monitor and collect data to demonstrate 
continuous compliance?

    (a) You must monitor and collect data according to this section.
    (b) Except for, as appropriate, monitor malfunctions, associated 
repairs, and required quality assurance or control activities 
(including, as applicable, calibration checks and required zero and 
span adjustments), you must conduct all monitoring in continuous 
operation at all times that the process unit is operating. For purposes 
of calculating data averages, you must not use data recorded during 
monitoring malfunctions, associated repairs, out-of-control periods, or 
required quality assurance or control activities. You must use all the 
data collected during all other periods in assessing compliance. A 
monitoring malfunction is any sudden, infrequent, not reasonably 
preventable failure of the monitoring to provide valid data. Monitoring 
failures that are caused in part by poor maintenance or careless 
operation are not malfunctions. Any period for which the monitoring 
system is out-of-control and data are not available for required 
calculations constitutes a deviation from the monitoring requirements.
    (c) You may not use data recorded during monitoring malfunctions, 
associated repairs, and required quality assurance or control 
activities; data recorded during periods of startup, shutdown, and 
malfunction; or data recorded during periods of control device downtime 
covered in any approved routine control device maintenance exemption in 
data averages and calculations used to report emission or operating 
levels, nor may such data be used in fulfilling a minimum data 
availability requirement, if applicable. You must use all the data 
collected during all other periods in assessing the operation of the 
control system.
    (d) Except as provided in paragraph (e) of this section, determine 
the 3-hour block average of all recorded readings, calculated after 
every 3 hours of operation as the average of the evenly spaced recorded 
readings in the previous 3 operating hours (excluding periods described 
in paragraphs (b) and (c) of this section).
    (e) For dry rotary dryer and veneer redryer wood moisture 
monitoring, dry rotary dryer temperature monitoring, biofilter bed 
temperature monitoring, and biofilter outlet THC monitoring, determine 
the 24-hour block average of all recorded readings, calculated after 
every 24 hours of operation as the average of the evenly spaced 
recorded readings in the previous 24 operating hours (excluding periods 
described in paragraphs (b) and (c) of this section).
    (f) To calculate the data averages for each 3-hour or 24-hour 
averaging period, you must have at least 75 percent of the required 
recorded readings for that period using only recorded readings that are 
based on valid data (i.e., not from periods described in paragraphs (b) 
and (c) of this section).


Sec.  63.2271  How do I demonstrate continuous compliance with the 
compliance options, operating requirements, and work practice 
requirements?

    (a) You must demonstrate continuous compliance with the compliance 
options, operating requirements, and work practice requirements in 
Sec. Sec.  63.2240 and 63.2241 that apply to you according to the 
methods specified in Tables 7 and 8 to this subpart.
    (b) You must report each instance in which you did not meet each 
compliance option, operating requirement, and work practice requirement 
in Tables 7 and 8 to this subpart that applies to you. This includes 
periods of startup, shutdown, and malfunction and periods of control 
device maintenance specified in paragraphs (b)(1) through (3) of this 
section. These instances are deviations from the compliance options, 
operating requirements, and work practice requirements in this subpart. 
These deviations must be reported according to the requirements in 
Sec.  63.2281.
    (1) During periods of startup, shutdown, and malfunction, you must 
operate in accordance with the SSMP.
    (2) Consistent with Sec. Sec.  63.6(e) and 63.7(e)(1), deviations 
that occur during a period of startup, shutdown, or malfunction are not 
violations if you demonstrate to the EPA Administrator's satisfaction 
that you were operating in accordance with the SSMP. The EPA 
Administrator will determine whether deviations that occur during a 
period of startup, shutdown, or malfunction are violations, according 
to the provisions in Sec.  63.6(e).
    (3) Deviations that occur during periods of control device 
maintenance covered by any approved routine control device maintenance 
exemption are not violations if you demonstrate to the EPA 
Administrator's satisfaction that you were operating in accordance with 
the approved routine control device maintenance exemption.

Notifications, Reports, and Records


Sec.  63.2280  What notifications must I submit and when?

    (a) You must submit all of the notifications in Sec. Sec.  63.7(b) 
and (c), 63.8(e), (f)(4) and (f)(6), 63.9 (b) through (e), and (g) and 
(h) by the dates specified.
    (b) You must submit an Initial Notification no later than 120 
calendar days after September 28, 2004, or after initial startup, 
whichever is later, as specified in Sec.  63.9(b)(2).
    (c) If you are required to conduct a performance test, you must 
submit a written notification of intent to conduct a performance test 
at least 60 calendar days before the performance test is scheduled to 
begin as specified in Sec.  63.7(b)(1).
    (d) If you are required to conduct a performance test, design 
evaluation, or other initial compliance demonstration as specified in 
Tables 4, 5, and 6 to this subpart, you must submit a Notification of 
Compliance Status as specified in Sec.  63.9(h)(2)(ii).
    (1) For each initial compliance demonstration required in Table 5 
or 6 to this subpart that does not include a performance test, you must 
submit the Notification of Compliance Status before the close of 
business on the 30th calendar day following the completion of the 
initial compliance demonstration.
    (2) For each initial compliance demonstration required in Tables 5 
and 6 to this subpart that includes a performance test conducted 
according to the requirements in Table 4 to this subpart, you must 
submit the Notification of Compliance Status, including the performance 
test results, before the close of business on the 60th calendar day 
following the completion of the performance test according to Sec.  
63.10(d)(2).
    (e) If you request a routine control device maintenance exemption

[[Page 46019]]

according to Sec.  63.2251, you must submit your request for the 
exemption no later than 30 days before the compliance date.
    (f) If you use the emissions averaging compliance option in Sec.  
63.2240(c), you must submit an Emissions Averaging Plan to the EPA 
Administrator for approval no later than 1 year before the compliance 
date or no later than 1 year before the date you would begin using an 
emissions average, whichever is later. The Emissions Averaging Plan 
must include the information in paragraphs (f)(1) through (6) of this 
section.
    (1) Identification of all the process units to be included in the 
emissions average indicating which process units will be used to 
generate credits, and which process units that are subject to 
compliance options in Tables 1A and 1B to this subpart will be 
uncontrolled (used to generate debits) or under-controlled (used to 
generate debits and credits).
    (2) Description of the control system used to generate emission 
credits for each process unit used to generate credits.
    (3) Determination of the total HAP control efficiency for the 
control system used to generate emission credits for each credit-
generating process unit.
    (4) Calculation of the RMR and AMR, as calculated using Equations 1 
through 3 of Sec.  63.2240(c)(1).
    (5) Documentation of total HAP measurements made according to Sec.  
63.2240(c)(2)(iv) and other relevant documentation to support 
calculation of the RMR and AMR.
    (6) A summary of the operating parameters you will monitor and 
monitoring methods for each debit-generating and credit-generating 
process unit.
    (g) You must notify the EPA Administrator within 30 days before you 
take any of the actions specified in paragraphs (g)(1) through (3) of 
this section.
    (1) You modify or replace the control system for any process unit 
subject to the compliance options and operating requirements in this 
subpart.
    (2) You shut down any process unit included in your Emissions 
Averaging Plan.
    (3) You change a continuous monitoring parameter or the value or 
range of values of a continuous monitoring parameter for any process 
unit or control device.


Sec.  63.2281  What reports must I submit and when?

    (a) You must submit each report in Table 9 to this subpart that 
applies to you.
    (b) Unless the EPA Administrator has approved a different schedule 
for submission of reports under Sec.  63.10(a), you must submit each 
report by the date in Table 9 to this subpart and as specified in 
paragraphs (b)(1) through (5) of this section.
    (1) The first compliance report must cover the period beginning on 
the compliance date that is specified for your affected source in Sec.  
63.2233 ending on June 30 or December 31, and lasting at least 6 
months, but less than 12 months. For example, if your compliance date 
is March 1, then the first semiannual reporting period would begin on 
March 1 and end on December 31.
    (2) The first compliance report must be postmarked or delivered no 
later than July 31 or January 31 for compliance periods ending on June 
30 and December 31, respectively.
    (3) Each subsequent compliance report must cover the semiannual 
reporting period from January 1 through June 30 or the semiannual 
reporting period from July 1 through December 31.
    (4) Each subsequent compliance report must be postmarked or 
delivered no later than July 31 or January 31 for the semiannual 
reporting period ending on June 30 and December 31, respectively.
    (5) For each affected source that is subject to permitting 
regulations pursuant to 40 CFR part 70 or 40 CFR part 71, and if the 
permitting authority has established dates for submitting semiannual 
reports pursuant to Sec.  70.6(a)(3)(iii)(A) or Sec.  
71.6(a)(3)(iii)(A), you may submit the first and subsequent compliance 
reports according to the dates the permitting authority has established 
instead of according to the dates in paragraphs (b)(1) through (4) of 
this section.
    (c) The compliance report must contain the information in 
paragraphs (c)(1) through (8) of this section.
    (1) Company name and address.
    (2) Statement by a responsible official with that official's name, 
title, and signature, certifying the truth, accuracy, and completeness 
of the content of the report.
    (3) Date of report and beginning and ending dates of the reporting 
period.
    (4) If you had a startup, shutdown, or malfunction during the 
reporting period and you took actions consistent with your SSMP, the 
compliance report must include the information specified in Sec.  
63.10(d)(5)(i).
    (5) A description of control device maintenance performed while the 
control device was offline and one or more of the process units 
controlled by the control device was operating, including the 
information specified in paragraphs (c)(5)(i) through (iii) of this 
section.
    (i) The date and time when the control device was shut down and 
restarted.
    (ii) Identification of the process units that were operating and 
the number of hours that each process unit operated while the control 
device was offline.
    (iii) A statement of whether or not the control device maintenance 
was included in your approved routine control device maintenance 
exemption developed pursuant to Sec.  63.2251. If the control device 
maintenance was included in your approved routine control device 
maintenance exemption, then you must report the information in 
paragraphs (c)(5)(iii)(A) through (C) of this section.
    (A) The total amount of time that each process unit controlled by 
the control device operated during the semiannual compliance period and 
during the previous semiannual compliance period.
    (B) The amount of time that each process unit controlled by the 
control device operated while the control device was down for 
maintenance covered under the routine control device maintenance 
exemption during the semiannual compliance period and during the 
previous semiannual compliance period.
    (C) Based on the information recorded under paragraphs 
(c)(5)(iii)(A) and (B) of this section for each process unit, compute 
the annual percent of process unit operating uptime during which the 
control device was offline for routine maintenance using Equation 1 of 
this section.
[GRAPHIC] [TIFF OMITTED] TR72AD04.007

Where:

RM = Annual percentage of process unit uptime during which control 
device is down for routine control device maintenance;
PUp = Process unit uptime for the previous semiannual 
compliance period;
PUc = Process unit uptime for the current semiannual 
compliance period;
DTp = Control device downtime claimed under the routine 
control device maintenance exemption for the previous semiannual 
compliance period;
DTc = Control device downtime claimed under the routine 
control device maintenance exemption for the

[[Page 46020]]

current semiannual compliance period.

    (6) The results of any performance tests conducted during the 
semiannual reporting period.
    (7) If there are no deviations from any applicable compliance 
option or operating requirement, and there are no deviations from the 
requirements for work practice requirements in Table 8 to this subpart, 
a statement that there were no deviations from the compliance options, 
operating requirements, or work practice requirements during the 
reporting period.
    (8) If there were no periods during which the continuous monitoring 
system (CMS), including CEMS and CPMS, was out-of-control as specified 
in Sec.  63.8(c)(7), a statement that there were no periods during 
which the CMS was out-of-control during the reporting period.
    (d) For each deviation from a compliance option or operating 
requirement and for each deviation from the work practice requirements 
in Table 8 to this subpart that occurs at an affected source where you 
are not using a CMS to comply with the compliance options, operating 
requirements, or work practice requirements in this subpart, the 
compliance report must contain the information in paragraphs (c)(1) 
through (6) of this section and in paragraphs (d)(1) and (2) of this 
section. This includes periods of startup, shutdown, and malfunction 
and routine control device maintenance.
    (1) The total operating time of each affected source during the 
reporting period.
    (2) Information on the number, duration, and cause of deviations 
(including unknown cause, if applicable), as applicable, and the 
corrective action taken.
    (e) For each deviation from a compliance option or operating 
requirement occurring at an affected source where you are using a CMS 
to comply with the compliance options and operating requirements in 
this subpart, you must include the information in paragraphs (c)(1) 
through (6) and paragraphs (e)(1) through (11) of this section. This 
includes periods of startup, shutdown, and malfunction and routine 
control device maintenance.
    (1) The date and time that each malfunction started and stopped.
    (2) The date and time that each CMS was inoperative, except for 
zero (low-level) and high-level checks.
    (3) The date, time, and duration that each CMS was out-of-control, 
including the information in Sec.  63.8(c)(8).
    (4) The date and time that each deviation started and stopped, and 
whether each deviation occurred during a period of startup, shutdown, 
or malfunction; during a period of control device maintenance covered 
in your approved routine control device maintenance exemption; or 
during another period.
    (5) A summary of the total duration of the deviation during the 
reporting period and the total duration as a percent of the total 
source operating time during that reporting period.
    (6) A breakdown of the total duration of the deviations during the 
reporting period into those that are due to startup, shutdown, control 
system problems, control device maintenance, process problems, other 
known causes, and other unknown causes.
    (7) A summary of the total duration of CMS downtime during the 
reporting period and the total duration of CMS downtime as a percent of 
the total source operating time during that reporting period.
    (8) A brief description of the process units.
    (9) A brief description of the CMS.
    (10) The date of the latest CMS certification or audit.
    (11) A description of any changes in CMS, processes, or controls 
since the last reporting period.
    (f) If you comply with the emissions averaging compliance option in 
Sec.  63.2240(c), you must include in your semiannual compliance report 
calculations based on operating data from the semiannual reporting 
period that demonstrate that actual mass removal equals or exceeds the 
required mass removal.
    (g) Each affected source that has obtained a title V operating 
permit pursuant to 40 CFR part 70 or 40 CFR part 71 must report all 
deviations as defined in this subpart in the semiannual monitoring 
report required by Sec.  70.6(a)(3)(iii)(A) or Sec.  
71.6(a)(3)(iii)(A). If an affected source submits a compliance report 
pursuant to Table 9 to this subpart along with, or as part of, the 
semiannual monitoring report required by Sec.  70.6(a)(3)(iii)(A) or 
Sec.  71.6(a)(3)(iii)(A), and the compliance report includes all 
required information concerning deviations from any compliance option, 
operating requirement, or work practice requirement in this subpart, 
submission of the compliance report shall be deemed to satisfy any 
obligation to report the same deviations in the semiannual monitoring 
report. However, submission of a compliance report shall not otherwise 
affect any obligation the affected source may have to report deviations 
from permit requirements to the permitting authority.


Sec.  63.2282  What records must I keep?

    (a) You must keep the records listed in paragraphs (a)(1) through 
(4) of this section.
    (1) A copy of each notification and report that you submitted to 
comply with this subpart, including all documentation supporting any 
Initial Notification or Notification of Compliance Status that you 
submitted, according to the requirements in Sec.  63.10(b)(2)(xiv).
    (2) The records in Sec.  63.6(e)(3)(iii) through (v) related to 
startup, shutdown, and malfunction.
    (3) Documentation of your approved routine control device 
maintenance exemption, if you request such an exemption under Sec.  
63.2251.
    (4) Records of performance tests and performance evaluations as 
required in Sec.  63.10(b)(2)(viii).
    (b) You must keep the records required in Tables 7 and 8 to this 
subpart to show continuous compliance with each compliance option, 
operating requirement, and work practice requirement that applies to 
you.
    (c) For each CEMS, you must keep the following records.
    (1) Records described in Sec.  63.10(b)(2)(vi) through (xi).
    (2) Previous (i.e., superseded) versions of the performance 
evaluation plan as required in Sec.  63.8(d)(3).
    (3) Request for alternatives to relative accuracy testing for CEMS 
as required in Sec.  63.8(f)(6)(i).
    (4) Records of the date and time that each deviation started and 
stopped, and whether the deviation occurred during a period of startup, 
shutdown, or malfunction or during another period.
    (d) If you comply with the emissions averaging compliance option in 
Sec.  63.2240(c), you must keep records of all information required to 
calculate emission debits and credits.
    (e) If you operate a catalytic oxidizer, you must keep records of 
annual catalyst activity checks and subsequent corrective actions.


Sec.  63.2283  In what form and how long must I keep my records?

    (a) Your records must be in a form suitable and readily available 
for expeditious review as specified in Sec.  63.10(b)(1).
    (b) As specified in Sec.  63.10(b)(1), you must keep each record 
for 5 years following the date of each occurrence, measurement, 
maintenance, corrective action, report, or record.
    (c) You must keep each record on site for at least 2 years after 
the date of each

[[Page 46021]]

occurrence, measurement, maintenance, corrective action, report, or 
record according to Sec.  63.10(b)(1). You can keep the records offsite 
for the remaining 3 years.

Other Requirements and Information


Sec.  63.2290  What parts of the General Provisions apply to me?

    Table 10 to this subpart shows which parts of the General 
Provisions in Sec. Sec.  63.1 through 63.13 apply to you.


Sec.  63.2291  Who implements and enforces this subpart?

    (a) This subpart can be implemented and enforced by the U.S. EPA or 
a delegated authority such as your State, local, or tribal agency. If 
the EPA Administrator has delegated authority to your State, local, or 
tribal agency, then that agency has the authority to implement and 
enforce this subpart. You should contact your EPA Regional Office to 
find out if this subpart is delegated to your State, local, or tribal 
agency.
    (b) In delegating implementation and enforcement authority of this 
subpart to a State, local, or tribal agency under 40 CFR part 63, 
subpart E, the authorities contained in paragraph (c) of this section 
are retained by the EPA Administrator and are not transferred to the 
State, local, or tribal agency.
    (c) The authorities that will not be delegated to State, local, or 
tribal agencies are listed in paragraphs (c)(1) through (5) of this 
section.
    (1) Approval of alternatives to the compliance options, operating 
requirements, and work practice requirements in Sec. Sec.  63.2240 and 
63.2241 as specified in Sec.  63.6(g). For the purposes of delegation 
authority under 40 CFR part 63, subpart E, ``compliance options'' 
represent ``emission limits''; ``operating requirements'' represent 
``operating limits''; and ``work practice requirements'' represent 
``work practice standards.''
    (2) Approval of major alternatives to test methods as specified in 
Sec.  63.7(e)(2)(ii) and (f) and as defined in Sec.  63.90.
    (3) Approval of major alternatives to monitoring as specified in 
Sec.  63.8(f) and as defined in Sec.  63.90.
    (4) Approval of major alternatives to recordkeeping and reporting 
as specified in Sec.  63.10(f) and as defined in Sec.  63.90.
    (5) Approval of PCWP sources demonstrations of eligibility for the 
low-risk subcategory developed according to appendix B of this subpart.


Sec.  63.2292  What definitions apply to this subpart?

    Terms used in this subpart are defined in the Clean Air Act (CAA), 
in 40 CFR 63.2, the General Provisions, and in this section as follows:
    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, 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.
    Agricultural fiber means the fiber of an annual agricultural crop. 
Examples of agricultural fibers include, but are not limited to, wheat 
straw, rice straw, and bagasse.
    Biofilter means an enclosed control system such as a tank or series 
of tanks with a fixed roof that contact emissions with a solid media 
(such as bark) and use microbiological activity to transform organic 
pollutants in a process exhaust stream to innocuous compounds such as 
carbon dioxide, water, and inorganic salts. Wastewater treatment 
systems such as aeration lagoons or activated sludge systems are not 
considered to be biofilters.
    Capture device means a hood, enclosure, or other means of 
collecting emissions into a duct so that the emissions can be measured.
    Capture efficiency means the fraction (expressed as a percentage) 
of the pollutants from an emission source that are collected by a 
capture device.
    Catalytic oxidizer means a control system that combusts or 
oxidizes, in the presence of a catalyst, exhaust gas from a process 
unit. Catalytic oxidizers include regenerative catalytic oxidizers and 
thermal catalytic oxidizers.
    Combustion unit means a dryer burner, process heater, or boiler 
used for combustion of organic HAP emissions.
    Control device means any equipment that reduces the quantity of HAP 
emitted to the air. The device may destroy the HAP or secure the HAP 
for subsequent recovery. Control devices include, but are not limited 
to, thermal or catalytic oxidizers, combustion units that incinerate 
process exhausts, biofilters, and condensers.
    Control system or add-on control system means the combination of 
capture and control devices used to reduce HAP emissions to the 
atmosphere.
    Conveyor strand dryer means a conveyor dryer 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 conveyor strand dryer is a process unit.
    Conveyor strand dryer zone means each portion of a conveyor strand 
dryer with a separate heat exchange system and exhaust vent(s). 
Conveyor strand dryers contain multiple zones (e.g., three zones), 
which may be divided into multiple sections.
    Deviation means any instance in which an affected source subject to 
this subpart, or an owner or operator of such a source:
    (1) Fails to meet any requirement or obligation established by this 
subpart including, but not limited to, any compliance option, operating 
requirement, or work practice requirement;
    (2) Fails to meet any term or condition that is adopted to 
implement an applicable requirement in this subpart, and that is 
included in the operating permit for any affected source required to 
obtain such a permit; or
    (3) Fails to meet any compliance option, operating requirement, or 
work practice requirement in this subpart during startup, shutdown, or 
malfunction, regardless of whether or not such failure is permitted by 
this subpart. A deviation is not always a violation. The determination 
of whether a deviation constitutes a violation of the standard is up to 
the discretion of the entity responsible for enforcement of the 
standards.
    Dryer heated zones means the zones of a softwood veneer dryer or 
fiberboard mat dryer that are equipped with heating and hot air 
circulation units. The cooling zone(s) of the dryer through which 
ambient air is blown are not part of the dryer heated zones.
    Dry forming means the process of making a mat of resinated fiber to 
be compressed into a reconstituted wood product such as particleboard, 
oriented strandboard, medium density fiberboard, or hardboard.

[[Page 46022]]

    Dry rotary dryer means a rotary dryer that dries wood particles or 
fibers with a maximum inlet moisture content of less than or equal to 
30 percent (by weight, dry basis) and operates with a maximum inlet 
temperature of less than or equal to 600[deg]F. A dry rotary dryer is a 
process unit.
    Fiber means the discrete elements of wood or similar cellulosic 
material, which are separated by mechanical means, as in refining, that 
can be formed into boards.
    Fiberboard means a composite panel composed of cellulosic fibers 
(usually wood or agricultural material) made by wet forming and 
compacting a mat of fibers. Fiberboard density generally is less than 
0.50 grams per cubic centimeter (31.5 pounds per cubic foot).
    Fiberboard mat dryer means a dryer used to reduce the moisture of 
wet-formed wood fiber mats by operation at elevated temperature. A 
fiberboard mat dryer is a process unit.
    Flame zone means the portion of the combustion chamber in a 
combustion unit that is occupied by the flame envelope.
    Furnish means the fibers, particles, or strands used for making 
boards.
    Glue-laminated beam means a structural wood beam made by bonding 
lumber together along its faces with resin.
    Green rotary dryer means a rotary dryer that dries wood particles 
or fibers with an inlet moisture content of greater than 30 percent (by 
weight, dry basis) at any dryer inlet temperature or operates with an 
inlet temperature of greater than 600[deg]F with any inlet moisture 
content. A green rotary dryer is a process unit.
    Group 1 miscellaneous coating operations means application of edge 
seals, nail lines, logo (or other information) paint, shelving edge 
fillers, trademark/gradestamp inks, and wood putty patches to plywood 
and composite wood products (except kiln-dried lumber) on the same site 
where the plywood and composite wood products are manufactured. Group 1 
miscellaneous coating operations also include application of synthetic 
patches to plywood at new affected sources.
    Hardboard means a composite panel composed of inter-felted 
cellulosic fibers made by dry or wet forming and pressing of a 
resinated fiber mat. Hardboard generally has a density of 0.50 grams 
per cubic centimeter (31.5 pounds per cubic foot) or greater.
    Hardboard oven means an oven used to heat treat or temper hardboard 
after hot pressing. Humidification chambers are not considered as part 
of hardboard ovens. A hardboard oven is a process unit.
    Hardwood means the wood of a broad-leafed tree, either deciduous or 
evergreen. Examples of hardwoods include, but are not limited to, 
aspen, birch, poplar, and oak.
    Hardwood veneer dryer means a dryer that removes excess moisture 
from veneer by conveying the veneer through a heated medium on rollers, 
belts, cables, or wire mesh. Hardwood veneer dryers are used to dry 
veneer with less than 30 percent softwood species on an annual volume 
basis. Veneer kilns that operate as batch units, veneer dryers heated 
by radio frequency or microwaves that are used to redry veneer, and 
veneer redryers (defined elsewhere in this section) that are heated by 
conventional means are not considered to be hardwood veneer dryers. A 
hardwood veneer dryer is a process unit.
    Kiln-dried lumber means solid wood lumber that has been dried in a 
lumber kiln.
    Laminated strand lumber (LSL) means a composite product formed into 
a billet made of thin wood strands cut from whole logs, resinated, and 
pressed together with the grain of each strand oriented parallel to the 
length of the finished product.
    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 includes 
parallel strand lumber (PSL).
    Lumber kiln means an enclosed dryer operated at elevated 
temperature to reduce the moisture content of lumber.
    Medium density fiberboard (MDF) means a composite panel composed of 
cellulosic fibers (usually wood or agricultural fiber) made by dry 
forming and pressing of a resinated fiber mat.
    Method detection limit means the minimum concentration of an 
analyte that can be determined with 99 percent confidence that the true 
value is greater than zero.
    Miscellaneous coating operations means application of any of the 
following to plywood or composite wood products: edge seals, moisture 
sealants, anti-skid coatings, company logos, trademark or grade stamps, 
nail lines, synthetic patches, wood patches, wood putty, concrete 
forming oils, glues for veneer composing, and shelving edge fillers. 
Miscellaneous coating operations also include the application of primer 
to oriented strandboard siding that occurs at the same site as oriented 
strandboard manufacture and application of asphalt, clay slurry, or 
titanium dioxide coatings to fiberboard at the same site of fiberboard 
manufacture.
    MSF means thousand square feet (92.9 square meters). Square footage 
of panels is usually measured on a thickness basis, such as \3/8\-inch, 
to define the total volume of panels. Equation 6 of Sec.  63.2262(j) 
shows how to convert from one thickness basis to another.
    Nondetect data means, for the purposes of this subpart, any value 
that is below the method detection limit.
    Non-HAP coating means a coating with HAP contents below 0.1 percent 
by mass for Occupational Safety and Health Administration-defined 
carcinogens as specified in 29 CFR 1910.1200(d)(4), and below 1.0 
percent by mass for other HAP compounds.
    1-hour period means a 60-minute period.
    Oriented strandboard (OSB) means a composite panel produced from 
thin wood strands cut from whole logs, formed into resinated layers 
(with the grain of strands in one layer oriented perpendicular to the 
strands in adjacent layers), and pressed.
    Oven-dried ton(s) (ODT) means tons of wood dried until all of the 
moisture in the wood is removed. One oven-dried ton equals 907 oven-
dried kilograms.
    Partial wood products enclosure means an enclosure that does not 
meet the design criteria for a wood products enclosure as defined in 
this subpart.
    Particle means a discrete, small piece of cellulosic material 
(usually wood or agricultural fiber) produced mechanically and used as 
the aggregate for a particleboard.
    Particleboard means 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.
    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 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 structural panel or engineered wood product. 
Plywood and composite wood products manufacturing facilities also 
include facilities that manufacture dry veneer and lumber kilns located 
at any

[[Page 46023]]

facility. Plywood and composite wood products include, but are not 
limited to, plywood, veneer, 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 of a wet-formed fiber mat before the mat enters 
a hot press. A press predryer is a process unit.
    Pressurized refiner means a piece of equipment operated under 
pressure for preheating (usually by steaming) wood material and 
refining (rubbing or grinding) the wood material into fibers. 
Pressurized refiners are operated with continuous infeed and outfeed of 
wood material and maintain elevated internal pressures (i.e., there is 
no pressure release) throughout the preheating and refining process. A 
pressurized refiner is a process unit.
    Primary tube dryer means a single-stage tube dryer or the first 
stage of a multi-stage tube dryer. Tube dryer stages are separated by 
vents for removal of moist gases between stages (e.g., a product 
cyclone at the end of a single-stage dryer or between the first and 
second stages of a multi-stage tube dryer). The first stage of a multi-
stage tube dryer is used to remove the majority of the moisture from 
the wood furnish (compared to the moisture reduction in subsequent 
stages of the tube dryer). Blow-lines used to apply resin are 
considered part of the primary tube dryer. A primary tube dryer is a 
process unit.
    Process unit means equipment classified according to its function 
such as a blender, dryer, press, former, or board cooler.
    Reconstituted wood product board cooler means a piece of equipment 
designed to reduce the temperature of a board by means of forced air or 
convection within a controlled time period after the board exits the 
reconstituted wood product press unloader. Board coolers include wicket 
and star type coolers commonly found at medium density fiberboard and 
particleboard plants. Board coolers do not include cooling sections of 
dryers (e.g., veneer dryers or fiberboard mat dryers) or coolers 
integrated into or following hardboard bake ovens or humidifiers. A 
reconstituted wood product board cooler is a process unit.
    Reconstituted wood product press means a press, including (if 
applicable) the press unloader, that presses a resinated mat of wood 
fibers, particles, or strands between hot platens or hot rollers to 
compact and set the mat into a panel by simultaneous application of 
heat and pressure. Reconstituted wood product presses are used in the 
manufacture of hardboard, medium density fiberboard, particleboard, and 
oriented strandboard. Extruders are not considered to be reconstituted 
wood product presses. A reconstituted wood product press is a process 
unit.
    Representative operating conditions means operation of a process 
unit during performance testing under the conditions that the process 
unit will typically be operating in the future, including use of a 
representative range of materials (e.g., wood material of a typical 
species mix and moisture content or typical resin formulation) and 
representative operating temperature range.
    Resin means the synthetic adhesive (including glue) or natural 
binder, including additives, used to bond wood or other cellulosic 
materials together to produce plywood and composite wood products.
    Responsible official means responsible official as defined in 40 
CFR 70.2 and 40 CFR 71.2.
    Rotary strand dryer means a rotary dryer operated at elevated 
temperature 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.
    Secondary tube dryer means the second stage and subsequent stages 
following the primary stage of a multi-stage tube dryer. Secondary tube 
dryers, also referred to as relay dryers, operate at lower temperatures 
than the primary tube dryer they follow. Secondary tube dryers are used 
to remove only a small amount of the furnish moisture compared to the 
furnish moisture reduction across the primary tube dryer. A secondary 
tube dryer is a process unit.
    Softwood means the wood of a coniferous tree. Examples of softwoods 
include, but are not limited to, Southern yellow pine, Douglas fir, and 
White spruce.
    Softwood veneer dryer means a dryer that removes excess moisture 
from veneer by conveying the veneer through a heated medium, generally 
on rollers, belts, cables, or wire mesh. Softwood veneer dryers are 
used to dry veneer with greater than or equal to 30 percent softwood 
species on an annual volume basis. Veneer kilns that operate as batch 
units, veneer dryers heated by radio frequency or microwaves that are 
used to redry veneer, and veneer redryers (defined elsewhere in this 
section) that are heated by conventional means are not considered to be 
softwood veneer dryers. A softwood veneer dryer is a process unit.
    Startup means bringing equipment online and starting the production 
process.
    Startup, initial means the first time equipment is put into 
operation. Initial startup does not include operation solely for 
testing equipment. Initial startup does not include subsequent startups 
(as defined in this section) following malfunction or shutdowns or 
following changes in product or between batch operations. Initial 
startup does not include startup of equipment that occurred when the 
source was an area source.
    Startup, shutdown, and malfunction plan (SSMP) means a plan 
developed according to the provisions of Sec.  63.6(e)(3).
    Strand means a long (with respect to thickness and width), flat 
wood piece specially cut from a log for use in oriented strandboard, 
laminated strand lumber, or other wood strand-based product.
    Temporary total enclosure (TTE) means an enclosure constructed for 
the purpose of measuring the capture efficiency of pollutants emitted 
from a given source, as defined in Method 204 of 40 CFR part 51, 
appendix M.
    Thermal oxidizer means a control system that combusts or oxidizes 
exhaust gas from a process unit. Thermal oxidizers include regenerative 
thermal oxidizers and combustion units.
    Total hazardous air pollutant emissions means, for purposes of this 
subpart, the sum of the emissions of the following six compounds: 
acetaldehyde, acrolein, formaldehyde, methanol, phenol, and 
propionaldehyde.
    Tube dryer means a single-stage or multi-stage dryer operated at 
elevated temperature and used 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. A tube dryer is a process unit.
    Veneer means thin sheets of wood peeled or sliced from logs for use 
in the manufacture of wood products such as plywood, laminated veneer 
lumber, or other products.
    Veneer redryer means a dryer heated by conventional means, such as 
direct wood-fired, direct-gas-fired, or steam heated, that is used to 
redry veneer that has been previously dried. Because the veneer dried 
in a veneer redryer has been previously dried, the inlet moisture 
content of the veneer entering the redryer is less than 25 percent (by 
weight, dry basis). Batch units used to redry veneer (such as redry 
cookers) are

[[Page 46024]]

not considered to be veneer redryers. A veneer redryer is a process 
unit.
    Wet control device means any equipment that uses water as a means 
of collecting an air pollutant. Wet control devices include scrubbers, 
wet electrostatic precipitators, and electrified filter beds. Wet 
control devices do not include biofilters or other equipment that 
destroys or degrades HAP.
    Wet forming means the process of making a slurry of water, fiber, 
and additives into a mat of fibers to be compressed into a fiberboard 
or hardboard product.
    Wood I-joists means a structural wood beam with an I-shaped cross 
section formed by bonding (with resin) wood or laminated veneer lumber 
flanges onto a web cut from a panel such as plywood or oriented 
strandboard.
    Wood products enclosure means a permanently installed containment 
that was designed to meet the following physical design criteria:
    (1) Any natural draft opening shall be at least four equivalent 
opening diameters from each HAP-emitting point, except for where board 
enters and exits the enclosure, unless otherwise specified by the EPA 
Administrator.
    (2) The total area of all natural draft openings shall not exceed 5 
percent of the surface area of the enclosure's four walls, floor, and 
ceiling.
    (3) The average facial velocity of air through all natural draft 
openings shall be at least 3,600 meters per hour (200 feet per minute). 
The direction of airflow through all natural draft openings shall be 
into the enclosure.
    (4) All access doors and windows whose areas are not included in 
item 2 of this definition and are not included in the calculation of 
facial velocity in item 3 of this definition shall be closed during 
routine operation of the process.
    (5) The enclosure is designed and maintained to capture all 
emissions for discharge through a control device.
    Work practice requirement means any design, equipment, work 
practice, or operational standard, or combination thereof, that is 
promulgated pursuant to section 112(h) of the CAA.

Tables to Subpart DDDD of Part 63

    Table 1A to Subpart DDDD of Part 63.--Production-Based Compliance
                                 Options
------------------------------------------------------------------------
                                           You must meet the following
                                           production-based compliance
 For the following process units . . .    option (total HAP \a\ basis) .
                                                       . .
------------------------------------------------------------------------
(1) Fiberboard mat dryer heated zones    0.022 lb/MSF \1/2\''.
 (at new affected sources only).
(2) Green rotary dryers................  0.058 lb/ODT.
(3) Hardboard ovens....................  0.022 lb/MSF \1/8\''.
(4) Press predryers (at new affected     0.037 lb/MSF \1/2\''.
 sources only).
(5) Pressurized refiners...............  0.039 lb/ODT.
(6) Primary tube dryers................  0.26 lb/ODT.
(7) Reconstituted wood product board     0.014 lb/MSF \3/4\''.
 coolers (at new affected sources only).
(8) Reconstituted wood product presses.  0.30 lb/MSF \3/4\''.
(9) Softwood veneer dryer heated zones.  0.022 lb/MSF \3/8\''.
(10) Rotary strand dryers..............  0.18 lb/ODT.
(11) Secondary tube dryers.............  0.010 lb/ODT.
------------------------------------------------------------------------
\a\ Total HAP, as defined in Sec.   63.2292, includes acetaldehyde,
  acrolein, formaldehyde, methanol, phenol, and propionaldehyde. lb/ODT
  = pounds per oven-dried ton; lb/MSF = pounds per thousand square feet
  with a specified thickness basis (inches). Section 63.2262(j) shows
  how to convert from one thickness basis to another.
Note: There is no production-based compliance option for conveyor strand
  dryers.


 Table 1B to Subpart DDDD of Part 63.--Add-on Control Systems Compliance
                                 Options
------------------------------------------------------------------------
                                         You must comply with one of the
For each of the following process units      following six compliance
                 . . .                    options by using an emissions
                                               control system . . .
------------------------------------------------------------------------
Fiberboard mat dryer heated zones (at    (1) Reduce emissions of total
 new affected sources only); green        HAP, measured as THC (as
 rotary dryers; hardboard ovens; press    carbon) \a\, by 90 percent; or
 predryers (at new affected sources      (2) Limit emissions of total
 only); pressurized refiners; primary     HAP, measured as THC (as
 tube dryers; secondary tube dryers;      carbon) \a\, to 20 ppmvd; or
 reconstituted wood product board        (3) Reduce methanol emissions
 coolers (at new affected sources         by 90 percent; or
 only); reconstituted wood product       (4) Limit methanol emissions to
 presses; softwood veneer dryer heated    less than or equal to 1 ppmvd
 zones; rotary strand dryers; conveyor    if uncontrolled methanol
 strand dryer zone one (at existing       emissions entering the control
 affected sources); and conveyor strand   device are greater than or
 dryer zones one and two (at new          equal to 10 ppmvd; or
 affected sources).                      (5) Reduce formaldehyde
                                          emissions by 90 percent; or
                                         (6) Limit formaldehyde
                                          emissions to less than or
                                          equal to 1 ppmvd if
                                          uncontrolled formaldehyde
                                          emissions entering the control
                                          device are greater than or
                                          equal to 10 ppmvd.
------------------------------------------------------------------------
\a\ You may choose to subtract methane from THC as carbon measurements.


       Table 2 to Subpart DDDD of Part 63.--Operating Requirements
------------------------------------------------------------------------
  If you operate a(n) . . .      You must . . .       Or you must . . .
------------------------------------------------------------------------
(1) Thermal oxidizer........  Maintain the 3-hour   Maintain the 3-hour
                               block average         block average THC
                               firebox temperature   concentration \a\
                               above the minimum     in the thermal
                               temperature           oxidizer exhaust
                               established during    below the maximum
                               the performance       concentration
                               test.                 established during
                                                     the performance
                                                     test.

[[Page 46025]]

 
(2) Catalytic oxidizer......  Maintain the 3-hour   Maintain the 3-hour
                               block average         block average THC
                               catalytic oxidizer    concentration \a\
                               temperature above     in the catalytic
                               the minimum           oxidizer exhaust
                               temperature           below the maximum
                               established during    concentration
                               the performance       established during
                               test; AND check the   the performance
                               activity level of a   test.
                               representative
                               sample of the
                               catalyst at least
                               every 12 months.
(3) Biofilter...............  Maintain the 24-hour  Maintain the 24-hour
                               block biofilter bed   block average THC
                               temperature within    concentration \a\
                               the range             in the biofilter
                               established           exhaust below the
                               according to Sec.     maximum
                               63.2262(m).           concentration
                                                     established during
                                                     the performance
                                                     test.
(4) Control device other      Petition the EPA      Maintain the 3-hour
 than a thermal oxidizer,      Administrator for     block average THC
 catalytic oxidizer, or        site-specific         concentration \a\
 biofilter.                    operating             in the control
                               parameter(s) to be    device exhaust
                               established during    below the maximum
                               the performance       concentration
                               test and maintain     established during
                               the average           the performance
                               operating             test.
                               parameter(s) within
                               the range(s)
                               established during
                               the performance
                               test.
(5) Process unit that meets   Maintain on a daily   Maintain the 3-hour
 a compliance option in        basis the process     block average THC
 Table 1A of this subpart,     unit controlling      concentration \a\
 or a process unit that        operating             in the process unit
 generates debits in an        parameter(s) within   exhaust below the
 emissions average without     the ranges            maximum
 the use of a control device.  established during    concentration
                               the performance       established during
                               test according to     the performance
                               Sec.   63.2262(n).    test.
------------------------------------------------------------------------
\a\ You may choose to subtract methane from THC measurements.


     Table 3 to Subpart DDDD of Part 63.--Work Practice Requirements
------------------------------------------------------------------------
  For the following process
   units at existing or new                  You must . . .
    affected sources . . .
------------------------------------------------------------------------
(1) Dry rotary dryers........  Process furnish with a 24-hour block
                                average inlet moisture content of less
                                than or equal to 30 percent (by weight,
                                dry basis); AND operate with a 24-hour
                                block average inlet dryer temperature of
                                less than or equal to 600[deg]F.
(2) Hardwood veneer dryers...  Process less than 30 volume percent
                                softwood species on an annual basis.
(3) Softwood veneer dryers...  Minimize fugitive emissions from the
                                dryer doors through (proper maintenance
                                procedures) and the green end of the
                                dryers (through proper balancing of the
                                heated zone exhausts).
(4) Veneer redryers..........  Process veneer that has been previously
                                dried, such that the 24-hour block
                                average inlet moisture content of the
                                veneer is less than or equal to 25
                                percent (by weight, dry basis).
(5) Group 1 miscellaneous      Use non-HAP coatings as defined in Sec.
 coating operations.            63.2292.
------------------------------------------------------------------------


 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.
(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 ASTM D6348-03
 63.2240(c).                                         (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.

[[Page 46026]]

 
(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)).
(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)).
(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 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.
 (11) Each process unit       Establish the site-   Data from the
 subject to a compliance       specific operating    parameter
 option in Table 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.
------------------------------------------------------------------------


  Table 5 to Subpart DDDD of Part 63.--Performance Testing and Initial
   Compliance Demonstrations for the Compliance Options and Operating
                              Requirements
------------------------------------------------------------------------
                                For the following
                               compliance options         You have
       For each . . .             and operating     demonstrated initial
                               requirements . . .    compliance if . . .
------------------------------------------------------------------------
(1) Process unit listed in    Meet the production-  The average total
 Table 1A to this subpart.     based compliance      HAP emissions
                               options listed in     measured using the
                               Table 1A to this      methods in Table 4
                               subpart.              to this subpart
                                                     over the 3-hour
                                                     performance test
                                                     are no greater than
                                                     the compliance
                                                     option in Table 1A
                                                     to this subpart;
                                                     AND you have a
                                                     record of the
                                                     operating
                                                     requirement(s)
                                                     listed in Table 2
                                                     to this subpart for
                                                     the process unit
                                                     over the
                                                     performance test
                                                     during which
                                                     emissions did not
                                                     exceed the
                                                     compliance option
                                                     value.

[[Page 46027]]

 
(2) Process unit listed in    Reduce emissions of   Total HAP emissions,
 Table 1B to this subpart.     total HAP, measured   measured using the
                               as THC, by 90         methods in Table 4
                               percent.              to this subpart
                                                     over the 3-hour
                                                     performance test,
                                                     are reduced by at
                                                     least 90 percent,
                                                     as calculated using
                                                     the procedures in
                                                     Sec.   63.2262; AND
                                                     you have a record
                                                     of the operating
                                                     requirement(s)
                                                     listed in Table 2
                                                     to this subpart for
                                                     the process unit
                                                     over the
                                                     performance test
                                                     during which
                                                     emissions were
                                                     reduced by at least
                                                     90 percent.
(3) Process unit listed in    Limit emissions of    The average total
 Table 1B to this subpart.     total HAP, measured   HAP emissions,
                               as THC, to 20 ppmvd.  measured using the
                                                     methods in Table 4
                                                     to this subpart
                                                     over the 3-hour
                                                     performance test,
                                                     do not exceed 20
                                                     ppmvd; AND you have
                                                     a record of the
                                                     operating
                                                     requirement(s)
                                                     listed in Table 2
                                                     to this subpart for
                                                     the process unit
                                                     over the
                                                     performance test
                                                     during which
                                                     emissions did not
                                                     exceed 20 ppmvd.
(4) Process unit listed in    Reduce methanol or    The methanol or
 Table 1B to this subpart.     formaldehyde          formaldehyde
                               emissions by 90       emissions measured
                               percent.              using the methods
                                                     in Table 4 to this
                                                     subpart over the 3-
                                                     hour performance
                                                     test, are reduced
                                                     by at least 90
                                                     percent, as
                                                     calculated using
                                                     the procedures in
                                                     Sec.   63.2262; AND
                                                     you have a record
                                                     of the operating
                                                     requirement(s)
                                                     listed in Table 2
                                                     to this subpart for
                                                     the process unit
                                                     over the
                                                     performance test
                                                     during which
                                                     emissions were
                                                     reduced by at least
                                                     90 percent.
(5) Process unit listed in    Limit methanol or     The average methanol
 Table 1B to this subpart.     formaldehyde          or formaldehyde
                               emissions to less     emissions, measured
                               than or equal to 1    using the methods
                               ppmvd (if             in Table 4 to this
                               uncontrolled          subpart over the 3-
                               emissions are         hour performance
                               greater than or       test, do not exceed
                               equal to 10 ppmvd).   1 ppmvd; AND you
                                                     have a record of
                                                     the operating
                                                     requirement(s)
                                                     listed in Table 2
                                                     to this subpart for
                                                     the process unit
                                                     over the
                                                     performance test
                                                     during which
                                                     emissions did not
                                                     exceed 1 ppmvd. If
                                                     the process unit is
                                                     a reconstituted
                                                     wood product press
                                                     or a reconstituted
                                                     wood product board
                                                     cooler, your
                                                     capture device
                                                     either meets the
                                                     EPA Method 204
                                                     criteria for a PTE
                                                     or achieves a
                                                     capture efficiency
                                                     of greater than or
                                                     equal to 95
                                                     percent.
(6) Reconstituted wood        Compliance options    You submit the
 product press at a new or     in Tables 1A and 1B   results of capture
 existing affected source,     to this subpart or    efficiency
 or reconstituted wood         the emissions         verification using
 product board cooler at a     averaging             the methods in
 new affected source.          compliance option     Table 4 to this
                               in Sec.               subpart with your
                               63.2240(c).           Notification of
                                                     Compliance Status.
(7) Process unit listed in    Compliance options    You submit with your
 Table 1B to this subpart      in Table 1B to this   Notification of
 controlled by routing         subpart or the        Compliance Status
 exhaust to a combustion       emissions averaging   documentation
 unit.                         compliance option     showing that the
                               in Sec.               process exhausts
                               63.2240(c).           controlled enter
                                                     into the flame zone
                                                     of your combustion
                                                     unit.
(8) Process unit listed in    Compliance options    You submit with your
 Table 1B to this subpart      in Table 1B to this   Notification of
 using a wet control device    subpart or the        Compliance Status
 as the sole means of          emissions averaging   your plan to
 reducing HAP emissions.       compliance option     address how organic
                               in Sec.               HAP captured in the
                               63.2240(c).           wastewater from the
                                                     wet control device
                                                     is contained or
                                                     destroyed to
                                                     minimize re-release
                                                     to the atmosphere.
------------------------------------------------------------------------


[[Page 46028]]


 Table 6 to Subpart DDDD of Part 63.--Initial Compliance Demonstrations
                     for Work Practice Requirements
------------------------------------------------------------------------
                                For the following         You have
       For each . . .             work practice     demonstrated initial
                               requirements . . .    compliance if . . .
------------------------------------------------------------------------
(1) Dry rotary dryer........  Process furnish with  You meet the work
                               an inlet moisture     practice
                               content less than     requirement AND you
                               or equal to 30        submit a signed
                               percent (by weight,   statement with the
                               dry basis) AND        Notification of
                               operate with an       Compliance Status
                               inlet dryer           that the dryer
                               temperature of less   meets the criteria
                               than or equal to      of a ``dry rotary
                               600 [deg]F.           dryer'' AND you
                                                     have a record of
                                                     the inlet moisture
                                                     content and inlet
                                                     dryer temperature
                                                     (as required in
                                                     Sec.   63.2263).
(2) Hardwood veneer dryer...  Process less than 30  You meet the work
                               volume percent        practice
                               softwood species.     requirement AND you
                                                     submit a signed
                                                     statement with the
                                                     Notification of
                                                     Compliance Status
                                                     that the dryer
                                                     meets the criteria
                                                     of a ``hardwood
                                                     veneer dryer'' AND
                                                     you have a record
                                                     of the percentage
                                                     of softwoods
                                                     processed in the
                                                     dryer (as required
                                                     in Sec.   63.2264).
(3) Softwood veneer dryer...  Minimize fugitive     You meet the work
                               emissions from the    practice
                               dryer doors and the   requirement AND you
                               green end.            submit with the
                                                     Notification of
                                                     Compliance Status a
                                                     copy of your plan
                                                     for minimizing
                                                     fugitive emissions
                                                     from the veneer
                                                     dryer heated zones
                                                     (as required in
                                                     Sec.   63.2265).
(4) Veneer redryers.........  Process veneer with   You meet the work
                               an inlet moisture     practice
                               content of less       requirement AND you
                               than or equal to 25   submit a signed
                               percent (by weight,   statement with the
                               dry basis).           Notification of
                                                     Compliance Status
                                                     that the dryer
                                                     operates only as a
                                                     redryer AND you
                                                     have a record of
                                                     the veneer inlet
                                                     moisture content of
                                                     the veneer
                                                     processed in the
                                                     redryer (as
                                                     required in Sec.
                                                     63.2266).
(5) Group 1 miscellaneous     Use non-HAP coatings  You meet the work
 coating operations.           as defined in Sec.    practice
                                63.2292.             requirement AND you
                                                     submit a signed
                                                     statement with the
                                                     Notification of
                                                     Compliance Status
                                                     that you are using
                                                     non-HAP coatings
                                                     AND you have a
                                                     record showing that
                                                     you are using non-
                                                     HAP coatings.
------------------------------------------------------------------------


   Table 7 to Subpart DDDD of Part 63.--Continuous Compliance With the
              Compliance Options and Operating Requirements
------------------------------------------------------------------------
                                For the following   You must demonstrate
                               compliance options        continuous
          For . . .               and operating      compliance by . . .
                               requirements . . .
------------------------------------------------------------------------
(1) Each process unit listed  Compliance options    Collecting and
 in Table 1B to this subpart   in Table 1B to this   recording the
 or used in calculation of     subpart or the        operating parameter
 an emissions average under    emissions averaging   monitoring system
 Sec.   63.2240(c).            compliance option     data listed in
                               in Sec.               Table 2 to this
                               63.2240(c) and the    subpart for the
                               operating             process unit
                               requirements in       according to Sec.
                               Table 2 to this       63.2269(a) through
                               subpart based on      (b) and Sec.
                               monitoring of         63.2270; AND
                               operating             reducing the
                               parameters.           operating parameter
                                                     monitoring system
                                                     data to the
                                                     specified averages
                                                     in units of the
                                                     applicable
                                                     requirement
                                                     according to
                                                     calculations in
                                                     Sec.   63.2270; 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 Sec.
                                                     63.2262.
(2) Each process unit listed  Compliance options    Collecting and
 in Tables 1A and 1B to this   in Tables 1A and 1B   recording the THC
 subpart or used in            to this subpart or    monitoring data
 calculation of an emissions   the emissions         listed in Table 2
 average under Sec.            averaging             to this subpart for
 63.2240(c).                   compliance option     the process unit
                               in Sec.               according to Sec.
                               63.2240(c) and the    63.2269(d); AND
                               operating             reducing the CEMS
                               requirements in       data to 3-hour
                               Table 2 of this       block averages
                               subpart based on      according to
                               THC CEMS data.        calculations in
                                                     Sec.   63.2269(d);
                                                     AND maintaining the
                                                     3-hour block
                                                     average THC
                                                     concentration in
                                                     the exhaust gases
                                                     less than or equal
                                                     to the THC
                                                     concentration
                                                     established
                                                     according to Sec.
                                                     63.2262.

[[Page 46029]]

 
(3) Each process unit using   Compliance options    Conducting a repeat
 a biofilter.                  in Tables 1B to       performance test
                               this subpart or the   using the
                               emissions averaging   applicable
                               compliance option     method(s) specified
                               in Sec.               in Table 4 to this
                               63.2240(c).           subpart within 2
                                                     years following the
                                                     previous
                                                     performance test
                                                     and within 180 days
                                                     after each
                                                     replacement of any
                                                     portion of the
                                                     biofilter bed media
                                                     with a different
                                                     type of media or
                                                     each replacement of
                                                     more than 50
                                                     percent (by volume)
                                                     of the biofilter
                                                     bed media with the
                                                     same type of media.
(4) Each process unit using   Compliance options    Checking the
 a catalytic oxidizer.         in Table 1B to this   activity level of a
                               subpart or the        representative
                               emissions averaging   sample of the
                               compliance option     catalyst at least
                               in Sec.               every 12 months and
                               63.2240(c).           taking any
                                                     necessary
                                                     corrective action
                                                     to ensure that the
                                                     catalyst is
                                                     performing within
                                                     its design range.
(5) Each process unit listed  Compliance options    Collecting and
 in Table 1A to this           in Table 1A to this   recording on a
 subpart, or each process      subpart or the        daily basis process
 unit without a control        emissions averaging   unit controlling
 device used in calculation    compliance option     operating parameter
 of an emissions averaging     in Sec.               data; AND
 debit under Sec.              63.2240(c) and the    maintaining the
 63.2240(c).                   operating             operating parameter
                               requirements in       at or above the
                               Table 2 to this       minimum, at or
                               subpart based on      below the maximum,
                               monitoring of         or within the range
                               process unit          (whichever applies)
                               controlling           established
                               operating             according to Sec.
                               parameters.           63.2262.
(6) Each Process unit listed  Compliance options    Implementing your
 in Table 1B to this subpart   in Table 1B to this   plan to address how
 using a wet control device    subpart or the        organic HAP
 as the sole means of          emissions averaging   captured in the
 reducing HAP emissions.       compliance option     wastewater from the
                               in Sec.               wet control device
                               63.2240(c).           is contained or
                                                     destroyed to
                                                     minimize re-release
                                                     to the atmosphere.
------------------------------------------------------------------------


Table 8 to Subpart DDDD of Part 63.--Continuous Compliance With the Work
                          Practice Requirements
------------------------------------------------------------------------
                                                    You must demonstrate
                                For the following        continuous
          For . . .               work practice      compliance by . . .
                               requirements . . .
------------------------------------------------------------------------
(1) Dry rotary dryer........  Process furnish with  Maintaining the 24-
                               an inlet moisture     hour block average
                               content less than     inlet furnish
                               or equal to 30        moisture content at
                               percent (by weight,   less than or equal
                               dry basis) AND        to 30 percent (by
                               operate with an       weight, dry basis)
                               inlet dryer           AND maintaining the
                               temperature of less   24-hour block
                               than or equal to      average inlet dryer
                               600 [deg]F.           temperature at less
                                                     than or equal to
                                                     600 [deg]F; AND
                                                     keeping records of
                                                     the inlet
                                                     temperature of
                                                     furnish moisture
                                                     content and inlet
                                                     dryer temperature.
(2) Hardwood veneer dryer...  Process less than 30  Maintaining the
                               volume percent        volume percent
                               softwood species.     softwood species
                                                     processed below 30
                                                     percent AND keeping
                                                     records of the
                                                     volume percent
                                                     softwood species
                                                     processed.
(3) Softwood veneer dryer...  Minimize fugitive     Following (and
                               emissions from the    documenting that
                               dryer doors and the   you are following)
                               green end.            your plan for
                                                     minimizing fugitive
                                                     emissions.
(4) Veneer redryers.........  Process veneer with   Maintaining the 24-
                               an inlet moisture     hour block average
                               content of less       inlet moisture
                               than or equal to 25   content of the
                               percent (by weight,   veneer processed at
                               dry basis).           or below of less
                                                     than or 25 percent
                                                     AND keeping records
                                                     of the inlet
                                                     moisture content of
                                                     the veneer
                                                     processed.
(5) Group 1 miscellaneous     Use non-HAP coatings  Continuing to use
 coating operations.           as defined in Sec.    non-HAP coatings
                                63.2292.             AND keeping records
                                                     showing that you
                                                     are using non-HAP
                                                     coatings.
------------------------------------------------------------------------


      Table 9 to Subpart DDDD of Part 63.--Requirements for Reports
------------------------------------------------------------------------
                                 The report must     You must submit the
 You must submit a(n) . . .       contain . . .         report . . .
------------------------------------------------------------------------
(1) Compliance report.......  The information in    Semiannually
                               Sec.   63.2281(c)     according to the
                               through (g).          requirements in
                                                     Sec.   63.2281(b).
(2) immediate startup,        (i) Actions taken     By fax or telephone
 shutdown, and malfunction     for the event.        within 2 working
 report if you had a                                 days after starting
 startup, shutdown, or                               actions
 malfunction during the                              inconsistent with
 reporting period that is                            the plan.
 not consistent with your
 SSMP.

[[Page 46030]]

 
                              (ii) The information  By letter within 7
                               in Sec.               working days after
                               63.10(d)(5)(ii).      the end of the
                                                     event unless you
                                                     have made
                                                     alternative
                                                     arrangements with
                                                     the permitting
                                                     authority.
------------------------------------------------------------------------


            Table 10 to Subpart DDDD of Part 63.--Applicability of General Provisions to Subpart DDDD
----------------------------------------------------------------------------------------------------------------
              Citation                        Subject             Brief description     Applies to  subpart DDDD
----------------------------------------------------------------------------------------------------------------
Sec.   63.1.........................  Applicability..........  Initial applicability   Yes.
                                                                determination;
                                                                applicability after
                                                                standard established;
                                                                permit requirements;
                                                                extensions,
                                                                notifications.
Sec.   63.2.........................  Definitions............  Definitions for part    Yes.
                                                                63 standards.
Sec.   63.3.........................  Units and Abbreviations  Units and               Yes.
                                                                abbreviations for
                                                                part 63 standards.
Sec.   63.4.........................  Prohibited Activities..  Prohibited activities;  Yes.
                                                                compliance date;
                                                                circumvention,
                                                                fragmentation.
Sec.   63.5.........................  Construction/            Applicability;          Yes.
                                       Reconstruction.          applications;
                                                                approvals.
Sec.   63.6(a)......................  Applicability..........  GP apply unless         Yes.
                                                                compliance extension;
                                                                GP apply to area
                                                                sources that become
                                                                major.
Sec.   63.6(b)(1)-(4)...............  Compliance Dates for     Standards apply at      Yes.
                                       New and Reconstructed    effective date; 3
                                       Sources.                 years after effective
                                                                date; upon startup;
                                                                10 years after
                                                                construction or
                                                                reconstruction
                                                                commences for section
                                                                112(f).
Sec.   63.6(b)(5)...................  Notification...........  Must notify if          Yes.
                                                                commenced
                                                                construction or
                                                                reconstruction after
                                                                proposal.
Sec.   63.6(b)(6)...................  [Reserved].............
Sec.   63.6(b)(7)...................  Compliance Dates for     Area sources that       Yes.
                                       New and Reconstructed    become major must
                                       Area Sources that        comply with major
                                       Become Major.            source standards
                                                                immediately upon
                                                                becoming major,
                                                                regardless of whether
                                                                required to comply
                                                                when they were an
                                                                area source.
Sec.   63.6(c)(1)-(2)...............  Compliance Dates for     Comply according to     Yes.
                                       Existing Sources.        date in subpart,
                                                                which must be no
                                                                later than 3 years
                                                                after effective date;
                                                                for section 112(f)
                                                                standards, comply
                                                                within 90 days of
                                                                effective date unless
                                                                compliance extension.
Sec.   63.6(c)(3)-(4)...............  [Reserved].............
Sec.   63.6(c)(5)...................  Compliance Dates for     Area sources that       Yes.
                                       Existing Area Sources    become major must
                                       that Become Major.       comply with major
                                                                source standards by
                                                                date indicated in
                                                                subpart or by
                                                                equivalent time
                                                                period (e.g., 3
                                                                years).
Sec.   63.6(d)......................  [Reserved].............
Sec.   63.6(e)(1)-(2)...............  Operation & Maintenance  Operate to minimize     Yes.
                                                                emissions at all
                                                                times; correct
                                                                malfunctions as soon
                                                                as practicable;
                                                                operation and
                                                                maintenance
                                                                requirements
                                                                independently
                                                                enforceable;
                                                                information
                                                                Administrator will
                                                                use to determine if
                                                                operation and
                                                                maintenance
                                                                requirements were met.
Sec.   63.6(e)(3)...................  Startup, Shutdown, and   Requirement for SSM     Yes.
                                       Malfunction Plan         and SSMP; content of
                                       (SSMP).                  SSMP.
Sec.   63.6(f)(1)...................  Compliance Except        You must comply with    Yes.
                                       During SSM.              emission standards at
                                                                all times except
                                                                during SSM.
Sec.   63.6(f)(2)-(3)...............  Methods for Determining  Compliance based on     Yes.
                                       Compliance.              performance test,
                                                                operation and
                                                                maintenance plans,
                                                                records, inspection.
Sec.   63.6(g)(1)-(3)...............  Alternative Standard...  Procedures for getting  Yes.
                                                                an alternative
                                                                standard.
Sec.   63.6(h)(1)-(9)...............  Opacity/Visible          Requirements for        NA.
                                       Emission (VE)            opacity and visible
                                       Standards.               emission standards.
Sec.   63.6(i)(1)-(14)..............  Compliance Extension...  Procedures and          Yes.
                                                                criteria for
                                                                Administrator to
                                                                grant compliance
                                                                extension.
Sec.   63.6(i)(15)..................  [Reserved].............
Sec.   63.6(i)(16)..................  Compliance Extension...  Compliance extension    Yes.
                                                                and Administrator's
                                                                authority.

[[Page 46031]]

 
Sec.   63.6(j)......................  Presidential Compliance  President may exempt    Yes.
                                       Exemption.               source category from
                                                                requirement to comply
                                                                with rule.
Sec.   63.7(a)(1)-(2)...............  Performance Test Dates.  Dates for conducting    Yes.
                                                                initial performance
                                                                testing and other
                                                                compliance
                                                                demonstrations; must
                                                                conduct 180 days
                                                                after first subject
                                                                to rule.
Sec.   63.7(a)(3)...................  Section 114 Authority..  Administrator may       Yes.
                                                                require a performance
                                                                test under CAA
                                                                section 114 at any
                                                                time.
Sec.   63.7(b)(1)...................  Notification of          Must notify             Yes.
                                       Performance Test.        Administrator 60 days
                                                                before the test.
Sec.   63.7(b)(2)...................  Notification of          If have to reschedule   Yes.
                                       Rescheduling.            performance test,
                                                                must notify
                                                                Administrator as soon
                                                                as practicable.
Sec.   63.7(c)......................  Quality Assurance/Test   Requirement to submit   Yes.
                                       Plan.                    site-specific test
                                                                plan 60 days before
                                                                the test or on date
                                                                Administrator agrees
                                                                with; test plan
                                                                approval procedures;
                                                                performance audit
                                                                requirements;
                                                                internal and external
                                                                QA procedures for
                                                                testing.
Sec.   63.7(d)......................  Testing Facilities.....  Requirements for        Yes.
                                                                testing facilities.
Sec.   63.7(e)(1)...................  Conditions for           Performance tests must  Yes.
                                       Conducting Performance   be conducted under
                                       Tests.                   representative
                                                                conditions; cannot
                                                                conduct performance
                                                                tests during SSM; not
                                                                a violation to exceed
                                                                standard during SSM.
Sec.   63.7(e)(2)...................  Conditions for           Must conduct according  Yes.
                                       Conducting Performance   to rule and EPA test
                                       Tests.                   methods unless
                                                                Administrator
                                                                approves alternative.
Sec.   63.7(e)(3)...................  Test Run Duration......  Must have three test    Yes.
                                                                runs for at least the
                                                                time specified in the
                                                                relevant standard;
                                                                compliance is based
                                                                on arithmetic mean of
                                                                three runs; specifies
                                                                conditions when data
                                                                from an additional
                                                                test run can be used.
Sec.   63.7(f)......................  Alternative Test Method  Procedures by which     Yes.
                                                                Administrator can
                                                                grant approval to use
                                                                an alternative test
                                                                method.
Sec.   63.7(g)......................  Performance Test Data    Must include raw data   Yes.
                                       Analysis.                in performance test
                                                                report; must submit
                                                                performance test data
                                                                60 days after end of
                                                                test with the
                                                                notification of
                                                                compliance status;
                                                                keep data for 5 years.
Sec.   63.7(h)......................  Waiver of Tests........  Procedures for          Yes.
                                                                Administrator to
                                                                waive performance
                                                                test.
Sec.   63.8(a)(1)...................  Applicability of         Subject to all          Yes.
                                       Monitoring               monitoring
                                       Requirements.            requirements in
                                                                standard.
Sec.   63.8(a)(2)...................  Performance              Performance             Yes.
                                       Specifications.          specifications in
                                                                appendix B of part 60
                                                                apply.
Sec.   63.8(a)(3)...................  [Reserved].............
Sec.   63.8(a)(4)...................  Monitoring with Flares.  Requirements for        NA.
                                                                flares in Sec.
                                                                63.11 apply.
Sec.   63.8(b)(1)...................  Monitoring.............  Must conduct            Yes.
                                                                monitoring according
                                                                to standard unless
                                                                Administrator
                                                                approves alternative.
Sec.   63.8(b)(2)-(3)...............  Multiple Effluents and   Specific requirements   Yes.
                                       Multiple Monitoring      for installing
                                       Systems.                 monitoring systems;
                                                                must install on each
                                                                effluent before it is
                                                                combined and before
                                                                it is released to the
                                                                atmosphere unless
                                                                Administrator
                                                                approves otherwise;
                                                                if more than one
                                                                monitoring system on
                                                                an emission point,
                                                                must report all
                                                                monitoring system
                                                                results, unless one
                                                                monitoring system is
                                                                a backup.
Sec.   63.8(c)(1)...................  Monitoring System        Maintain monitoring     Yes.
                                       Operation and            system in a manner
                                       Maintenance.             consistent with and
                                                                good air pollution
                                                                control practices.
Sec.   63.8(c)(1)(i)................  Operation and            Must maintain and       Yes.
                                       Maintenance of CMS.      operate CMS in
                                                                accordance with Sec.
                                                                 63.6(e)(1).
Sec.   63.8(c)(1)(ii)...............  Spare Parts for CMS....  Must maintain spare     Yes.
                                                                parts for routine CMS
                                                                repairs.

[[Page 46032]]

 
Sec.   63.8(c)(1)(iii)..............  SSMP for CMS...........  Must develop and        Yes.
                                                                implement SSMP for
                                                                CMS.
Sec.   63.8(c)(2)-(3)...............  Monitoring System        Must install to get     Yes.
                                       Installation.            representative
                                                                emission of parameter
                                                                measurements; must
                                                                verify operational
                                                                status before or at
                                                                performance test.
Sec.   63.8(c)(4)...................  Continuous Monitoring    CMS must be operating   Yes.
                                       System (CMS)             except during
                                       Requirements.            breakdown, out-of-
                                                                control, repair,
                                                                maintenance, and high-
                                                                level calibration
                                                                drifts; COMS must
                                                                have a minimum of one
                                                                cycle of sampling and
                                                                analysis for each
                                                                successive 10-second
                                                                period and one cycle
                                                                of data recording for
                                                                each successive 6-
                                                                minute period; CEMS
                                                                must have a minimum
                                                                of one cycle of
                                                                operation for each
                                                                successive 15-minute
                                                                period.
Sec.   63.8(c)(5)...................  Continuous Opacity       COMS minimum            NA.
                                       Monitoring System        procedures.
                                       (COMS) Minimum
                                       Procedures.
Sec.   63.8(c)(6)-(8)...............  CMS Requirements.......  Zero and high-level     Yes.
                                                                calibration check
                                                                requirements; out-of-
                                                                control periods.
Sec.   63.8(d)......................  CMS Quality Control....  Requirements for CMS    Yes.
                                                                quality control,
                                                                including
                                                                calibration, etc.;
                                                                must keep quality
                                                                control plan on
                                                                record for 5 years.
                                                                Keep old versions for
                                                                5 years after
                                                                revisions.
Sec.   63.8(e)......................  CMS Performance          Notification,           Yes.
                                       Evaluation.              performance
                                                                evaluation test plan,
                                                                reports.
Sec.   63.8(f)(1)-(5)...............  Alternative Monitoring   Procedures for          Yes.
                                       Method.                  Administrator to
                                                                approve alternative
                                                                monitoring.
Sec.   63.8(f)(6)...................  Alternative to Relative  Procedures for          Yes.
                                       Accuracy Test.           Administrator to
                                                                approve alternative
                                                                relative accuracy
                                                                tests for CEMS.
Sec.   63.8(g)......................  Data Reduction.........  COMS 6-minute averages  Yes.
                                                                calculated over at
                                                                least 36 evenly
                                                                spaced data points;
                                                                CEMS 1 hour averages
                                                                computed over at
                                                                least 4 equally
                                                                spaced data points;
                                                                data that can't be
                                                                used in average;
                                                                rounding of data.
Sec.   63.9(a)......................  Notification             Applicability and       Yes.
                                       Requirements.            State delegation.
Sec.   63.9(b)(1)-(2)...............  Initial Notifications..  Submit notification     Yes.
                                                                120 days after
                                                                effective date;
                                                                contents of
                                                                notification.
Sec.   63.9(b)(3)...................  [Reserved].............
Sec.   63.9(b)(4)-(5)...............  Initial Notifications..  Submit notification     Yes.
                                                                120 days after
                                                                effective date;
                                                                notification of
                                                                intent to construct/
                                                                reconstruct;
                                                                notification of
                                                                commencement of
                                                                construct/
                                                                reconstruct;
                                                                notification of
                                                                startup; contents of
                                                                each.
Sec.   63.9(c)......................  Request for Compliance   Can request if cannot   Yes.
                                       Extension.               comply by date or if
                                                                installed best
                                                                available control
                                                                technology/lowest
                                                                achievable emission
                                                                rate.
Sec.   63.9(d)......................  Notification of Special  For sources that        Yes.
                                       Compliance               commence construction
                                       Requirements for New     between proposal and
                                       Source.                  promulgation and want
                                                                to comply 3 years
                                                                after effective date.
Sec.   63.9(e)......................  Notification of          Notify EPA              Yes.
                                       Performance Test.        Administrator 60 days
                                                                prior.
Sec.   63.9(f)......................  Notification of Visible  Notify EPA              No.
                                       Emissions/Opacity Test.  Administrator 30 days
                                                                prior.
Sec.   63.9(g)......................  Additional               Notification of         Yes.
                                       Notifications When       performance
                                       Using CMS.               evaluation;
                                                                notification using
                                                                COMS data;
                                                                notification that
                                                                exceeded criterion
                                                                for relative accuracy.
Sec.   63.9(h)(1)-(6)...............  Notification of          Contents; due 60 days   Yes.
                                       Compliance Status.       after end of
                                                                performance test or
                                                                other compliance
                                                                demonstration, except
                                                                for opacity/VE, which
                                                                are due 30 days
                                                                after; when to submit
                                                                to Federal vs. State
                                                                authority.

[[Page 46033]]

 
Sec.   63.9(i)......................  Adjustment of Submittal  Procedures for          Yes.
                                       Deadlines.               Administrator to
                                                                approve change in
                                                                when notifications
                                                                must be submitted.
Sec.   63.9(j)......................  Change in Previous       Must submit within 15   Yes.
                                       Information.             days after the change.
Sec.   63.10(a).....................  Recordkeeping/Reporting  Applies to all, unless  Yes.
                                                                compliance extension;
                                                                when to submit to
                                                                Federal vs. State
                                                                authority; procedures
                                                                for owners of more
                                                                than one source.
Sec.   63.10(b)(1)..................  Recordkeeping/Reporting  General Requirements;   Yes.
                                                                keep all records
                                                                readily available;
                                                                keep for 5 years.
Sec.   63.10(b)(2)(i)-(iv)..........  Records Related to       Occurrence of each of   Yes.
                                       Startup, Shutdown, and   operation (process
                                       Malfunction.             equipment);
                                                                occurrence of each
                                                                malfunction of air
                                                                pollution equipment;
                                                                maintenance on air
                                                                pollution control
                                                                equipment; actions
                                                                during startup,
                                                                shutdown, and
                                                                malfunction.
Sec.   63.10(b)(2)(vi) and (x)-(xi).  CMS Records............  Malfunctions,           Yes.
                                                                inoperative, out-of-
                                                                control.
Sec.   63.10(b)(2)(vii)-(ix)........  Records................  Measurements to         Yes.
                                                                demonstrate
                                                                compliance with
                                                                compliance options
                                                                and operating
                                                                requirements;
                                                                performance test,
                                                                performance
                                                                evaluation, and
                                                                visible emission
                                                                observation results;
                                                                measurements to
                                                                determine conditions
                                                                of performance tests
                                                                and performance
                                                                evaluations.
Sec.   63.10(b)(2)(xii).............  Records................  Records when under      Yes.
                                                                waiver.
Sec.   63.10(b)(2)(xiii)............  Records................  Records when using      Yes.
                                                                alternative to
                                                                relative accuracy
                                                                test.
Sec.   63.10(b)(2)(xiv).............  Records................  All documentation       Yes.
                                                                supporting initial
                                                                notification and
                                                                notification of
                                                                compliance status.
Sec.   63.10(b)(3)..................  Records................  Applicability           Yes.
                                                                determinations.
Sec.   63.10(c)(1)-(6), (9)-(15)....  Records................  Additional records for  Yes.
                                                                CMS.
Sec.   63.10(c)(7)-(8)..............  Records................  Records of excess       No.
                                                                emissions and
                                                                parameter monitoring
                                                                exceedances for CMS.
Sec.   63.10(d)(1)..................  General Reporting        Requirement to report.  Yes.
                                       Requirements.
Sec.   63.10(d)(2)..................  Report of Performance    When to submit to       Yes.
                                       Test Results.            Federal or State
                                                                authority.
Sec.   63.10(d)(3)..................  Reporting Opacity or VE  What to report and      NA.
                                       Observations.            when.
Sec.   63.10(d)(4)..................  Progress Reports.......  Must submit progress    Yes.
                                                                reports on schedule
                                                                if under compliance
                                                                extension.
Sec.   63.10(d)(5)..................  Startup, Shutdown, and   Contents and            Yes.
                                       Malfunction Reports.     submission.
Sec.   63.10(e)(1)-(2)..............  Additional CMS Reports.  Must report results     Yes.
                                                                for each CEM on a
                                                                unit; written copy of
                                                                performance
                                                                evaluation; 3 copies
                                                                of COMS performance
                                                                evaluation.
Sec.   63.10(e)(3)..................  Reports................  Excess emission         No.
                                                                reports.
Sec.   63.10(e)(4)..................  Reporting COMS data....  Must submit COMS data   NA.
                                                                with performance test
                                                                data.
Sec.   63.10(f).....................  Waiver for               Procedures for EPA      Yes.
                                       Recordkeeping/           Administrator to
                                       Reporting.               waive.
Sec.   63.11........................  Flares.................  Requirements for        NA.
                                                                flares.
Sec.   63.12........................  Delegation.............  State authority to      Yes.
                                                                enforce standards.
Sec.   63.13........................  Addresses..............  Addresses where         Yes.
                                                                reports,
                                                                notifications, and
                                                                requests are send.
Sec.   63.14........................  Incorporation by         Test methods            Yes.
                                       Reference.               incorporated by
                                                                reference.
Sec.   63.15........................  Availability of          Public and              Yes.
                                       Information.             confidential
                                                                information.
----------------------------------------------------------------------------------------------------------------


[[Page 46034]]

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

1.0 Scope and Application

    This procedure has been developed specifically for the rule for 
the plywood and composite wood products (PCWP) industry and is used 
to determine the capture efficiency of a partial hot press enclosure 
in that industry. This procedure is applicable for the determination 
of capture efficiency for enclosures around hot presses and is an 
alternative to the construction of temporary total enclosures (TTE). 
Sulfur hexafluoride (SF6) is used as a tracer gas (other 
tracer gases may be used if approved by the EPA Administrator). This 
gas is not indigenous to the ambient atmosphere and is nonreactive.
    This procedure uses infrared spectrometry (IR) as the analytical 
technique. When the infrared spectrometer used is a Fourier-
Transform Infrared spectrometer (FTIR), an alternate instrument 
calibration procedure may be used; the alternate calibration 
procedure is the calibration transfer standard (CTS) procedure of 
EPA Method 320 (appendix A to 40 CFR part 63). Other analytical 
techniques which are capable of equivalent Method Performance 
(Section 13.0) also may be used. Specifically, gas chromatography 
with electron capture detection (GC/ECD) is an applicable technique 
for analysis of SF6.

2.0 Summary of Method

    A constant mass flow rate of SF6 tracer gas is 
released through manifolds at multiple locations within the 
enclosure to mimic the release of hazardous air pollutants during 
the press process. This test method requires a minimum of three 
SF6 injection points (two at the press unloader and one 
at the press) and provides details about considerations for locating 
the injection points. A GC/ECD is used to measure the concentration 
of SF6 at the inlet duct to the control device (outlet 
duct from enclosure). Simultaneously, EPA Method 2 (appendix A to 40 
CFR part 60) is used to measure the flow rate at the inlet duct to 
the control device. The concentration and flow rate measurements are 
used to calculate the mass emission rate of SF6 at the 
control device inlet. Through calculation of the mass of 
SF6 released through the manifolds and the mass of 
SF6 measured at the inlet to the control device, the 
capture efficiency of the enclosure is calculated.
    In addition, optional samples of the ambient air may be taken at 
locations around the perimeter of the enclosure to quantify the 
ambient concentration of SF6 and to identify those areas 
of the enclosure that may be performing less efficiently; these 
samples would be taken using disposable syringes and would be 
analyzed using a GC/ECD.
    Finally, in addition to the requirements specified in this 
procedure, the data quality objectives (DQO) or lower confidence 
limit (LCL) criteria specified in appendix A to 40 CFR part 63, 
subpart KK, Data Quality Objective and Lower Confidence Limit 
Approaches for Alternative Capture Efficiency Protocols and Test 
Methods, must also be satisfied. A minimum of three test runs are 
required for this procedure; however, additional test runs may be 
required based on the results of the DQO or LCL analysis.

3.0 Definitions

    3.1 Capture efficiency (CE). The weight per unit time of 
SF6 entering the control device divided by the weight per 
unit time of SF6 released through manifolds at multiple 
locations within the enclosure.
    3.2 Control device (CD). The equipment used to reduce, by 
destruction or removal, press exhaust air pollutants prior to 
discharge to the ambient air.
    3.3 Control/destruction efficiency (DE). The volatile organic 
compound or HAP removal efficiency of the control device.
    3.4 Data Quality Objective (DQO) Approach. A statistical 
procedure to determine the precision of the data from a test series 
and to qualify the data in the determination of capture efficiency 
for compliance purposes. If the results of the DQO analysis of the 
initial three test runs do not satisfy the DQO criterion, the LCL 
approach can be used or additional test runs must be conducted. If 
additional test runs are conducted, then the DQO or LCL analysis is 
conducted using the data from both the initial test runs and all 
additional test runs.
    3.5 Lower Confidence Limit (LCL) Approach. An alternative 
statistical procedure that can be used to qualify data in the 
determination of capture efficiency for compliance purposes. If the 
results of the LCL approach produce a CE that is too low for 
demonstrating compliance, then additional test runs must be 
conducted until the LCL or DQO is met. As with the DQO, data from 
all valid test runs must be used in the calculation.
    3.6 Minimum Measurement Level (MML). The minimum tracer gas 
concentration expected to be measured during the test series. This 
value is selected by the tester based on the capabilities of the IR 
spectrometer (or GC/ECD) and the other known or measured parameters 
of the hot press enclosure to be tested. The selected MML must be 
above the low-level calibration standard and preferably below the 
mid-level calibration standard.
    3.7 Method 204. The U.S. EPA Method 204, ``Criteria For and 
Verification of a Permanent or Temporary Total Enclosure'' (40 CFR 
part 51, appendix M).
    3.8 Method 205. The U.S. EPA Method 205, ``Verification of Gas 
Dilution Systems for Field Instrument Calibrations'' (40 CFR part 
51, appendix M).
    3.9 Method 320. The U.S. EPA Method 320, ``Measurement of Vapor 
Phase Organic and Inorganic Emissions by Extractive Fourier 
Transform Infrared (FTIR) Spectroscopy'' (40 CFR part 63, appendix 
A).
    3.10 Overall capture and control efficiency (CCE). The 
collection and control/destruction efficiency of both the PPE and CD 
combined. The CCE is calculated as the product of the CE and DE.
    3.11 Partial press enclosure (PPE). The physical barrier that 
``partially'' encloses the press equipment, captures a significant 
amount of the associated emissions, and transports those emissions 
to the CD.
    3.12 Test series. A minimum of three test runs or, when more 
than three runs are conducted, all of the test runs conducted.

4.0 Interferences

    There are no known interferences.

5.0 Safety

    Sulfur hexafluoride is a colorless, odorless, nonflammable 
liquefied gas. It is stable and nonreactive and, because it is 
noncorrosive, most structural materials are compatible with it. The 
Occupational Safety and Health Administration Permissible Emission 
Limit-Time Weighted Average (PEL-TWA) and Threshold Limit Value-Time 
Weighted Average (TLV-TWA) concentrations are 1,000 parts per 
million. Sulfur hexafluoride is an asphyxiant. Exposure to an 
oxygen-deficient atmosphere (less than 19.5 percent oxygen) may 
cause dizziness, drowsiness, nausea, vomiting, excess salivation, 
diminished mental alertness, loss of consciousness, and death. 
Exposure to atmospheres containing less than 12 percent oxygen will 
bring about unconsciousness without warning and so quickly that the 
individuals cannot help themselves. Contact with liquid or cold 
vapor may cause frostbite. Avoid breathing sulfur hexafluoride gas. 
Self-contained breathing apparatus may be required by rescue 
workers. Sulfur hexafluoride is not listed as a carcinogen or a 
potential carcinogen.

6.0 Equipment and Supplies

    This method requires equipment and supplies for: (a) the 
injection of tracer gas into the enclosure, (b) the measurement of 
the tracer gas concentration in the exhaust gas entering the control 
device, and (c) the measurement of the volumetric flow rate of the 
exhaust gas entering the control device. In addition, the requisite 
equipment needed for EPA Methods 1-4 in appendix A to 40 CFR part 60 
will be required. Equipment and supplies for optional ambient air 
sampling are discussed in Section 8.6.
    6.1 Tracer Gas Injection.
    6.1.1 Manifolds. This method requires the use of tracer gas 
supply cylinder(s) along with the appropriate flow control elements. 
Figure 1 shows a schematic drawing of the injection system showing 
potential locations for the tracer gas manifolds. Figure 2 shows a 
schematic drawing of the recommended configuration of the injection 
manifold. Three tracer gas discharge manifolds are required at a 
minimum.
    6.1.2 Flow Control Meter. Flow control and measurement meter for 
measuring the quantity of tracer gas injected. A mass flow, 
volumetric flow, or critical orifice control meter can be used for 
this method. The meter must be accurate to within  5 
percent at the flow rate used. This means that the flow meter must 
be calibrated against a primary standard for flow measurement at the 
appropriate flow rate.
    6.2 Measurement of Tracer Gas Concentration.
    6.2.1 Sampling Probes. Use Pyrex or stainless steel sampling 
probes of sufficient length to reach the traverse points calculated 
according to EPA Method 1 (appendix A to 40 CFR part 60).

[[Page 46035]]

    6.2.2 Sampling Line. Use a heated Teflon sampling line to 
transport the sample to the analytical instrument.
    6.2.3 Sampling Pump. Use a sampling pump capable of extracting 
sufficient sample from the duct and transporting to the analytical 
instrument.
    6.2.4 Sample Conditioning System. Use a particulate filter 
sufficient to protect the sampling pump and analytical instrument. 
At the discretion of the tester and depending on the equipment used 
and the moisture content of the exhaust gas, it may be necessary to 
further condition the sample by removing moisture using a condenser.
    6.2.5 Analytical Instrument. Use one of the following analytical 
instruments.
    6.2.5.1 Spectrometer. Use an infrared spectrometer designed to 
measuring SF6 tracer gas and capable of meeting or 
exceeding the specifications of this procedure. An FTIR meeting the 
specifications of Method 320 in appendix A to 40 CFR part 63 may be 
used.
    6.2.5.2 GC/ECD. Use a GC/ECD designed to measure SF6 
tracer gas and capable of meeting or exceeding the specifications of 
this procedure.
    6.2.6 Recorder. At a minimum, use a recorder with linear strip 
chart. An automated data acquisition system (DAS) is recommended.
    6.3 Exhaust Gas Flow Rate Measurement. Use equipment specified 
for EPA Methods 2, 3, and 4 in appendix A to 40 CFR part 60 for 
measuring flow rate of exhaust gas at the inlet to the control 
device.

7.0 Reagents and Standards

    7.1 Tracer Gas. Use SF6 as the tracer gas. The 
manufacturer of the SF6 tracer gas should provide a 
recommended shelf life for the tracer gas cylinder over which the 
concentration does not change more than  2 percent from 
the certified value. A gas mixture of SF6 diluted with 
nitrogen should be used; based on experience and calculations, pure 
SF6 gas is not necessary to conduct tracer gas testing. 
Select a concentration and flow rate that is appropriate for the 
analytical instrument's detection limit, the MML, and the exhaust 
gas flow rate from the enclosure (see section 8.1.1). You may use a 
tracer gas other than SF6 with the prior approval of the 
EPA Administrator. If you use an approved tracer gas other than 
SF6, all references to SF6 in this protocol 
instead refer to the approved tracer gas.
    7.2 Calibration Gases. The SF6 calibration gases 
required will be dependent on the selected MML and the appropriate 
span selected for the test. Commercial cylinder gases certified by 
the manufacturer to be accurate to within 1 percent of the certified 
label value are preferable, although cylinder gases certified by the 
manufacturer to 2 percent accuracy are allowed. Additionally, the 
manufacturer of the SF6 calibration gases should provide 
a recommended shelf life for each calibration gas cylinder over 
which the concentration does not change more than  2 
percent from the certified value. Another option allowed by this 
method is for the tester to obtain high concentration certified 
cylinder gases and then use a dilution system meeting the 
requirements of EPA Method 205, 40 CFR part 51, appendix M, to make 
multi-level calibration gas standards. Low-level, mid-level, and 
high-level calibration gases will be required. The MML must be above 
the low-level standard, the high-level standard must be no more than 
four times the low-level standard, and the mid-level standard must 
be approximately halfway between the high- and low-level standards. 
See section 12.1 for an example calculation of this procedure.

    Note: If using an FTIR as the analytical instrument, the tester 
has the option of following the CTS procedures of Method 320 in 
appendix A to 40 CFR part 63; the calibration standards (and 
procedures) specified in Method 320 may be used in lieu of the 
calibration standards and procedures in this protocol.

    7.2.1 Zero Gas. High purity nitrogen.
    7.2.2 Low-Level Calibration Gas. An SF6 calibration 
gas in nitrogen with a concentration equivalent to 20 to 30 percent 
of the applicable span value.
    7.2.3 Mid-Level Calibration Gas. An SF6 calibration 
gas in nitrogen with a concentration equivalent to 45 to 55 percent 
of the applicable span value.
    7.2.4 High-Level Calibration Gas. An SF6 calibration 
gas in nitrogen with a concentration equivalent to 80 to 90 percent 
of the applicable span value.

8.0 Sample Collection, Preservation, Storage, and Transport

    8.1 Test Design.
    8.1.1 Determination of Minimum Tracer Gas Flow Rate.
    8.1.1.1 Determine (via design calculations or measurements) the 
approximate flow rate of the exhaust gas through the enclosure, 
actual cubic feet per minute (acfm).
    8.1.1.2 Calculate the minimum tracer gas injection rate 
necessary to assure a detectable SF6 concentration at the 
exhaust gas measurement point (see section 12.1 for calculation).
    8.1.1.3 Select a flow meter for the injection system with an 
operating range appropriate for the injection rate selected.
    8.1.2 Determination of the Approximate Time to Reach 
Equilibrium.
    8.1.2.1 Determine the volume of the enclosure.
    8.1.2.2 Calculate the air changes per minute of the enclosure by 
dividing the approximate exhaust flow rate (8.1.1.1 above) by the 
enclosed volume (8.1.2.1 above).
    8.1.2.3 Calculate the time at which the tracer concentration in 
the enclosure will achieve approximate equilibrium. Divide 3 by the 
air changes per minute (8.1.2.2 above) to establish this time. This 
is the approximate length of time for the system to come to 
equilibrium. Concentration equilibrium occurs when the tracer 
concentration in the enclosure stops changing as a function of time 
for a constant tracer release rate. Because the press is 
continuously cycling, equilibrium may be exhibited by a repeating, 
but stable, cyclic pattern rather than a single constant 
concentration value. Assure sufficient tracer gas is available to 
allow the system to come to equilibrium, and to sample for a minimum 
of 20 minutes and repeat the procedure for a minimum of three test 
runs. Additional test runs may be required based on the results of 
the DQO and LCL analyses described in 40 CFR part 63, subpart KK, 
appendix A.
    8.1.3 Location of Injection Points. This method requires a 
minimum of three tracer gas injection points. The injection points 
should be located within leak prone, volatile organic compound/
hazardous air pollutant (VOC/HAP) producing areas around the press, 
or horizontally within 12 inches of the defined equipment. One 
potential configuration of the injection points is depicted in 
Figure 1. The effect of wind, exfiltration through the building 
envelope, and air flowing through open building doors should be 
considered when locating tracer gas injection points within the 
enclosure. The injection points should also be located at a vertical 
elevation equal to the VOC/HAP generating zones. The injection 
points should not be located beneath obstructions that would prevent 
a natural dispersion of the gas. Document the selected injection 
points in a drawing(s).
    8.1.4 Location of Flow Measurement and Tracer Sampling. Accurate 
CD inlet gas flow rate measurements are critical to the success of 
this procedure. Select a measurement location meeting the criteria 
of EPA Method 1 (40 CFR part 60, appendix A), Sampling and Velocity 
Traverses for Stationary Sources. Also, when selecting the 
measurement location, consider whether stratification of the tracer 
gas is likely at the location (e.g., do not select a location 
immediately after a point of air in-leakage to the duct).
    8.2 Tracer Gas Release. Release the tracer gas at a calculated 
flow rate (see section 12.1 for calculation) through a minimum of 
three injection manifolds located as described above in 8.1.3. The 
tracer gas delivery lines must be routed into the enclosure and 
attached to the manifolds without violating the integrity of the 
enclosure.
    8.3 Pretest Measurements.
    8.3.1 Location of Sampling Point(s). If stratification is not 
suspected at the measurement location, select a single sample point 
located at the centroid of the CD inlet duct or at a point no closer 
to the CD inlet duct walls than 1 meter. If stratification is 
suspected, establish a ``measurement line'' that passes through the 
centroidal area and in the direction of any expected stratification. 
Locate three traverse points at 16.7, 50.0 and 83.3 percent of the 
measurement line and sample from each of these three points during 
each run, or follow the procedure in section 8.3.2 to verify whether 
stratification does or does not exist.
    8.3.2 Stratification Verification. The presence or absence of 
stratification can be verified by using the following procedure. 
While the facility is operating normally, initiate tracer gas 
release into the enclosure. For rectangular ducts, locate at least 
nine sample points in the cross section such that the sample points 
are the centroids of similarly-shaped, equal area divisions of the 
cross section. Measure the tracer gas concentration at each point. 
Calculate the mean value for all sample points. For circular ducts, 
conduct a 12-point traverse (i.e., six points on each of the two 
perpendicular

[[Page 46036]]

diameters) locating the sample points as described in 40 CFR part 
60, appendix A, Method 1. Perform the measurements and calculations 
as described above. Determine if the mean pollutant concentration is 
more than 10 percent different from any single point. If so, the 
cross section is considered to be stratified, and the tester may not 
use a single sample point location, but must use the three traverse 
points at 16.7, 50.0, and 83.3 percent of the entire measurement 
line. Other traverse points may be selected, provided that they can 
be shown to the satisfaction of the Administrator to provide a 
representative sample over the stack or duct cross section.
    8.4 CD Inlet Gas Flow Rate Measurements. The procedures of EPA 
Methods 1-4 (40 CFR part 60, appendix A) are used to determine the 
CD inlet gas flow rate. Molecular weight (Method 3) and moisture 
(Method 4) determinations are only required once for each test 
series. However, if the test series is not completed within 24 
hours, then the molecular weight and moisture measurements should be 
repeated daily. As a minimum, velocity measurements are conducted 
according to the procedures of Methods 1 and 2 before and after each 
test run, as close to the start and end of the run as practicable. A 
velocity measurement between two runs satisfies both the criterion 
of ``after'' the run just completed and ``before'' the run to be 
initiated. Accurate exhaust gas flow rate measurements are critical 
to the success of this procedure. If significant temporal variations 
of flow rate are anticipated during the test run under normal 
process operating conditions, take appropriate steps to accurately 
measure the flow rate during the test. Examples of steps that might 
be taken include: (1) conducting additional velocity traverses 
during the test run; or (2) continuously monitoring a single point 
of average velocity during the run and using these data, in 
conjunction with the pre- and post-test traverses, to calculate an 
average velocity for the test run.
    8.5 Tracer Gas Measurement Procedure.
    8.5.1 Calibration Error Test. Immediately prior to the emission 
test (within 2 hours of the start of the test), introduce zero gas 
and high-level calibration gas at the calibration valve assembly. 
Zero and calibrate the analyzer according to the manufacturer's 
procedures using, respectively, nitrogen and the calibration gases. 
Calculate the predicted response for the low-level and mid-level 
gases based on a linear response line between the zero and high-
level response. Then introduce the low-level and mid-level 
calibration gases successively to the measurement system. Record the 
analyzer responses for the low-level and mid-level calibration gases 
and determine the differences between the measurement system 
responses and the predicted responses using the equation in section 
12.3. These differences must be less than 5 percent of the 
respective calibration gas value. If not, the measurement system 
must be replaced or repaired prior to testing. No adjustments to the 
measurement system shall be conducted after the calibration and 
before the drift determination (section 8.5.4). If adjustments are 
necessary before the completion of the test series, perform the 
drift checks prior to the required adjustments and repeat the 
calibration following the adjustments. If multiple electronic ranges 
are to be used, each additional range must be checked with a mid-
level calibration gas to verify the multiplication factor.

    Note: If using an FTIR for the analytical instrument, you may 
choose to follow the pretest preparation, evaluation, and 
calibration procedures of Method 320 (section 8.0) (40 CFR part 63, 
appendix A) in lieu of the above procedure.

    8.5.2 Response Time Test. Conduct this test once prior to each 
test series. Introduce zero gas into the measurement system at the 
calibration valve assembly. When the system output has stabilized, 
switch quickly to the high-level calibration gas. Record the time 
from the concentration change to the measurement system response 
equivalent to 95 percent of the step change. Repeat the test three 
times and average the results.
    8.5.3 SF6 Measurement. Sampling of the enclosure 
exhaust gas at the inlet to the CD should begin at the onset of 
tracer gas release. If necessary, adjust the tracer gas injection 
rate such that the measured tracer gas concentration at the CD inlet 
is within the spectrometer's calibration range (i.e., between the 
MML and the span value). Once the tracer gas concentration reaches 
equilibrium, the SF6 concentration should be measured 
using the infrared spectrometer continuously for at least 20 minutes 
per run. Continuously record (i.e., record at least once per minute) 
the concentration. Conduct at least three test runs. On the 
recording chart, in the data acquisition system, or in a log book, 
make a note of periods of process interruption or cyclic operation 
such as the cycles of the hot press operation. Table 1 to this 
appendix summarizes the physical measurements required for the 
enclosure testing.

    Note: If a GC/ECD is used as the analytical instrument, a 
continuous record (at least once per minute) likely will not be 
possible; make a minimum of five injections during each test run. 
Also, the minimum test run duration criterion of 20 minutes applies.

    8.5.4 Drift Determination. Immediately following the completion 
of the test run, reintroduce the zero and mid-level calibration 
gases, one at a time, to the measurement system at the calibration 
valve assembly. (Make no adjustments to the measurement system until 
both the zero and calibration drift checks are made.) Record the 
analyzer responses for the zero and mid-level calibration gases and 
determine the difference between the instrument responses for each 
gas prior to and after the emission test run using the equation in 
section 12.4. If the drift values exceed the specified limits 
(section 13), invalidate the test results preceding the check and 
repeat the test following corrections to the measurement system. 
Alternatively, recalibrate the test measurement system as in section 
8.5.1 and report the results using both sets of calibration data 
(i.e., data determined prior to the test period and data determined 
following the test period). Note: If using an FTIR for the 
analytical instrument, you may choose to follow the post-test 
calibration procedures of Method 320 in appendix A to 40 CFR part 63 
(section 8.11.2) in lieu of the above procedures.
    8.6 Ambient Air Sampling (Optional). Sampling the ambient air 
surrounding the enclosure is optional. However, taking these samples 
during the capture efficiency testing will identify those areas of 
the enclosure that may be performing less efficiently.
    8.6.1 Location of Ambient Samples Outside the Enclosure 
(Optional). In selecting the sampling locations for collecting 
samples of the ambient air surrounding the enclosure, consider 
potential leak points, the direction of the release, and laminar 
flow characteristics in the area surrounding the enclosure. Samples 
should be collected from all sides of the enclosure, downstream in 
the prevailing room air flow, and in the operating personnel 
occupancy areas.
    8.6.2 Collection of Ambient Samples (Optional). During the 
tracer gas release, collect ambient samples from the area 
surrounding the enclosure perimeter at predetermined location using 
disposable syringes or some other type of containers that are non-
absorbent, inert, and that have low permeability (i.e., polyvinyl 
fluoride film or polyester film sample bags or polyethylene, 
polypropylene, nylon or glass bottles). The use of disposable 
syringes allows samples to be injected directly into a gas 
chromatograph. Concentration measurements taken around the perimeter 
of the enclosure provide evidence of capture performance and will 
assist in the identification of those areas of the enclosure that 
are performing less efficiently.
    8.6.3 Analysis and Storage of Ambient Samples (Optional). 
Analyze the ambient samples using an analytical instrument 
calibrated and operated according to the procedures in this appendix 
or ASTM E 260 and ASTM E 697. Samples may be analyzed immediately 
after a sample is taken, or they may be stored for future analysis. 
Experience has shown no degradation of concentration in 
polypropylene syringes when stored for several months as long as the 
needle or syringe is plugged. Polypropylene syringes should be 
discarded after one use to eliminate the possibility of cross 
contamination of samples.

9.0 Quality Control

    9.1 Sampling, System Leak Check. A sampling system leak check 
should be conducted prior to and after each test run to ensure the 
integrity of the sampling system.
    9.2 Zero and Calibration Drift Tests.

[[Page 46037]]



----------------------------------------------------------------------------------------------------------------
           Section               Quality control measure                           Effect
----------------------------------------------------------------------------------------------------------------
8.5.4.......................  Zero and calibration drift    Ensures that bias introduced by drift in the
                               tests.                        measurement system output during the run is no
                                                             greater than 3 percent of span.
----------------------------------------------------------------------------------------------------------------

10.0 Calibration and Standardization

    10.1 Control Device Inlet Air Flow Rate Measurement Equipment. 
Follow the equipment calibration requirements specified in Methods 
2, 3, and 4 (appendix A to 40 CFR part 60) for measuring the 
velocity, molecular weight, and moisture of the control device inlet 
air.
    10.2 Tracer Gas Injection Rate. A dry gas volume flow meter, 
mass flow meter, or orifice can be used to measure the tracer gas 
injection flow rate. The selected flow measurement device must have 
an accuracy of greater than  5 percent at the field 
operating range. Prior to the test, verify the calibration of the 
selected flow measurement device using either a wet test meter, 
spirometer, or liquid displacement meter as the calibration device. 
Select a minimum of two flow rates to bracket the expected field 
operating range of the flow meter. Conduct three calibration runs at 
each of the two selected flow rates. For each run, note the exact 
quantity of gas as determined by the calibration standard and the 
gas volume indicated by the flow meter. For each flow rate, 
calculate the average percent difference of the indicated flow 
compared to the calibration standard.
    10.3 Spectrometer. Follow the calibration requirements specified 
by the equipment manufacturer for infrared spectrometer measurements 
and conduct the pretest calibration error test specified in section 
8.5.1. Note: if using an FTIR analytical instrument see Method 320, 
section 10 (appendix A to 40 CFR part 63).
    10.5 Gas Chromatograph. Follow the pre-test calibration 
requirements specified in section 8.5.1.
    10.4 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.

11.0 Analytical Procedures

    The sample collection and analysis are concurrent for this 
method (see section 8.0).

12.0 Calculations and Data Analysis

    12.1 Estimate MML and Span. The MML is the minimum measurement 
level. The selection of this level is at the discretion of the 
tester. However, the MML must be higher than the low-level 
calibration standard, and the tester must be able to measure at this 
level with a precision of <=10 percent. As an example, select the 
MML as 10 times the instrument's published detection limit. The 
detection limit of one instrument is 0.01 parts per million by 
volume (ppmv). Therefore, the MML would be 0.10 ppmv. Select the 
low-level calibration standard as 0.08 ppmv. The high-level standard 
would be four times the low-level standard or 0.32 ppmv. A 
reasonable mid-level standard would then be 0.20 ppmv (halfway 
between the low-level standard and the high-level standard). 
Finally, the span value would be approximately 0.40 ppmv (the high-
level value is 80 percent of the span). In this example, the 
following MML, calibration standards, and span values would apply:
MML = 0.10 ppmv
Low-level standard = 0.08 ppmv
Mid-level standard = 0.20 ppmv
High-level standard = 0.32 ppmv
Span value = 0.40 ppmv
    12.2 Estimate Tracer Gas Injection Rate for the Given Span. To 
estimate the minimum and maximum tracer gas injection rate, assume a 
worst case capture efficiency of 80 percent, and calculate the 
tracer gas flow rate based on known or measured parameters. To 
estimate the minimum tracer gas injection rate, assume that the MML 
concentration (10 times the IR detection limit in this example) is 
desired at the measurement location. The following equation can be 
used to estimate the minimum tracer gas injection rate:

((QT-MIN x 0.8)/QE) x (CT / 100) x 
106 = MML

QT-MIN = 1.25 x MML x (QE/CT) x 
10-4

Where:

QT-MIN = minimum volumetric flow rate of tracer gas 
injected, standard cubic feet per minute (scfm);
QE = volumetric flow rate of exhaust gas, scfm;
CT = Tracer gas (SF6) concentration in gas 
blend, percent by volume;
MML = minimum measured level, ppmv = 10 x IRDL (for this 
example);
IRDL = IR detection limit, ppmv.

    Standard conditions: 20[deg]C, 760 millimeters of mercury (mm 
Hg).
    To estimate the maximum tracer gas injection rate, assume that 
the span value is desired at the measurement location. The following 
equation can be used to estimate the maximum tracer gas injection 
rate:

((QT-MAX x 0.8)/QE) x (CT / 100) x 
106 = span value

QT-MAX = 1.25 x span value x (QE/
CT) x 10-4

Where:

QT-MAX = maximum volumetric flow rate of tracer gas 
injected, scfm;
Span value = instrument span value, ppmv.

    The following example illustrates this calculation procedure:
    Find the range of volumetric flow rate of tracer gas to be 
injected when the following parameters are known:

QE = 60,000 scfm (typical exhaust gas flow rate from an 
enclosure);
CT = 2 percent SF6 in nitrogen;
IRDL = 0.01 ppmv (per manufacturer's specifications);
MML = 10 x IRDL = 0.10 ppmv;
Span value = 0.40 ppmv;
QT = ?

Minimum tracer gas volumetric flow rate:

QT-MIN = 1.25 x MML x (QE/CT) x 
10-4

QT-MIN = 1.25 x 0.10 x (60,000/2) x 10-4 = 
0.375 scfm

Maximum tracer gas volumetric flow rate:

QT-MAX = 1.25 x span value x (QE/
CT) x 10-4

    QT-MAX = 1.25 x 0.40 x (60,000/2) x 10-4 = 
1.5 scfm

    In this example, the estimated total volumetric flow rate of the 
two percent SF6 tracer gas injected through the manifolds 
in the enclosure lies between 0.375 and 1.5 scfm.
    12.3 Calibration Error. Calculate the calibration error for the 
low-level and mid-level calibration gases using the following 
equation:

    Err = [bond]Cstd-Cmeas[bond] / 
Cstd x 100

Where:

Err = calibration error, percent;
Cstd = low-level or mid-level calibration gas value, 
ppmv;
Cmeas = measured response to low-level or mid-level 
concentration gas, ppmv.

    12.4 Calibration Drift. Calculate the calibration drift for the 
zero and low-level calibration gases using the following equation:

D = [bond]Cinitial - Cfinal [bond] / 
Cspan x 100

Where:

D = calibration drift, percent;
Cinitial = low-level or mid-level calibration gas value 
measured before test run, ppmv;
Cfinal = low-level or mid-level calibration gas value 
measured after test run, ppmv;
Cspan = span value, ppmv.

    12.5 Calculate Capture Efficiency. The equation to calculate 
enclosure capture efficiency is provided below:

CE = (SF6-CD / SF6-INJ) x 100

Where:

CE = capture efficiency;
SF6-CD = mass of SF6 measured at the inlet to 
the CD;
SF6-INJ= mass of SF6 injected from the tracer 
source into the enclosure.

Calculate the CE for each of the initial three test runs. Then 
follow the procedures outlined in section 12.6 to calculate the 
overall capture efficiency.
    12.6 Calculate Overall Capture Efficiency. After calculating the 
capture efficiency for each of the initial three test runs, follow 
the procedures in 40 CFR part 63, subpart KK, appendix A, to 
determine if the results of the testing can be used in determining 
compliance with the requirements of the rule. There are two methods 
that can be used: the DQO and LCL methods. The DQO method is 
described in section 3 of 40 CFR part 63, subpart KK, appendix A, 
and provides a measure of the precision of the capture efficiency 
testing conducted. Section 3 of 40 CFR part 63, subpart KK, appendix 
A, provides an example calculation using results from a facility. If 
the DQO criteria are met using the first set of three test runs, 
then

[[Page 46038]]

the facility can use the average capture efficiency of these test 
results to determine the capture efficiency of the enclosure. If the 
DQO criteria are not met, then the facility can conduct another set 
of three runs and run the DQO analysis again using the results from 
the six runs OR the facility can elect to use the LCL approach.
    The LCL method is described in section 4 of 40 CFR part 63, 
subpart KK, appendix A, and provides sources that may be performing 
much better than their regulatory requirement, a screening option by 
which they can demonstrate compliance. The LCL approach compares the 
80 percent lower confidence limit for the mean measured CE value to 
the applicable regulatory requirement. If the LCL capture efficiency 
is higher than the applicable limit, then the facility is in initial 
compliance and would use the LCL capture efficiency as the capture 
efficiency to determine compliance. If the LCL capture efficiency is 
lower than the applicable limit, then the facility must perform 
additional test runs and re-run the DQO or LCL analysis.

13.0 Method Performance

    13.1 Measurement System Performance Specifications.
    13.1.1 Zero Drift. Less than  3 percent of the span 
value.
    13.1.2 Calibration Drift. Less than  3 percent of 
the span value.
    13.1.3 Calibration Error. Less than  5 percent of 
the calibration gas value.
    13.2 Flow Measurement Specifications. The mass flow, volumetric 
flow, or critical orifice control meter used should have an accuracy 
of greater than  5 percent at the flow rate used.
    13.3 Calibration and Tracer Gas Specifications. The manufacturer 
of the calibration and tracer gases should provide a recommended 
shelf life for each calibration gas cylinder over which the 
concentration does not change more than  2 percent from 
the certified value.

14.0 Pollution Prevention [Reserved]

15.0 Waste Management [Reserved]

16.0 References

    1. 40 CFR part 60, appendix A, EPA Method 1--Sample and velocity 
traverses for stationary sources.
    2. 40 CFR part 60, appendix A, EPA Method 2--Determination of 
stack gas velocity and volumetric flow rate.
    3. 40 CFR part 60, appendix A, EPA Method 3--Gas analysis for 
the determination of dry molecular weight.
    4. 40 CFR part 60, appendix A, EPA Method 4--Determination of 
moisture content in stack gases.
    5. SEMI F15-93 Test Method for Enclosures Using Sulfur 
Hexafluoride Tracer Gas and Gas Chromotography.
    6. Memorandum from John S. Seitz, Director, Office of Air 
Quality Planning and Standards, to EPA Regional Directors, Revised 
Capture Efficiency Guidance for Control of Volatile Organic Compound 
Emissions, February 7, 1995. (That memorandum contains an attached 
technical document from Candace Sorrell, Emission Monitoring and 
Analysis Division, ``Guidelines for Determining Capture 
Efficiency,'' January 9, 1994).
    7. Technical Systems Audit of Testing at Plant ``C,'' EPA-454/R-
00-26, May 2000.
    8. Material Safety Data Sheet for SF6 Air Products 
and Chemicals, Inc. Website: www3.airproducts.com. October 2001.

17.0 Tables, Diagrams, Flowcharts, and Validation Data

     Table 1 to Appendix A to Subpart DDDD of 40 CFR Part 63.--Summary of Critical Physical Measurements for
                                                Enclosure Testing
----------------------------------------------------------------------------------------------------------------
                                          Measurement
           Measurement                  instrumentation         Measurement frequency       Measurement site
----------------------------------------------------------------------------------------------------------------
Tracer gas injection rate........  Mass flow meter,           Continuous..............  Injection manifolds
                                    volumetric flow meter or                             (cylinder gas).
                                    critical orifice.
Tracer gas concentration at        Infrared Spectrometer or   Continuous (at least one  Inlet duct to the
 control device inlet.              GC/ECD.                    reading per minute) for   control device (outlet
                                                               a minimum of 20 minutes.  duct of enclosure).
Volumetric air flow rate.........  EPA Methods 1, 2, 3, 4     Each test run for         Inlet duct to the
                                    (40 CFR part 60,           velocity (minimum);       control device (outlet
                                    appendix A).               Daily for moisture and    duct of enclosure).
                                    Velocity sensor    molecular weight.
                                    (Manometer/Pitot tube).
                                    Thermocouple....
                                    Midget Impinger
                                    sampler
                                    Orsat or Fyrite
----------------------------------------------------------------------------------------------------------------

BILLING CODE 6560-50-P

[[Page 46039]]

[GRAPHIC] [TIFF OMITTED] TR72AD04.008


[[Page 46040]]


[GRAPHIC] [TIFF OMITTED] TR72AD04.009

BILLING CODE 6560-50-C

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 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 conduct HAP emissions tests according to the 
requirements in paragraphs (b) through (h) of this section and the 
methods specified in Table 2 to this appendix for every process unit 
within the affected source that emits one or more of the HAP listed 
in Table 1 to this appendix. You must test the process units at your 
affected source to 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

[[Page 46041]]

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 the NCASI 
Method IM/CAN/WP-99.02 (incorporated by reference (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).
    (g) For purposes of your low-risk demonstration, you must assume 
that 17 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.

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 (measured according to section 5 of 
this appendix), calculate your total toxicity-weighted carcinogen 
and noncarcinogen emission rates for each of your process units 
using Equations 1 and 2 of this appendix, respectively.
[GRAPHIC] [TIFF OMITTED] TR72AD04.010

TWCER = Toxicity-weighted carcinogenic emission rate for each 
process unit (1b/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] TR72AD04.011

TWNER = Toxicity-weighted noncarcinogenic emission rate for each 
process unit (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)

    (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 process 
units. Identify the appropriate maximum allowable toxicity-weighted 
carcinogen emission rate from Table 3 to this appendix for your 
affected source using the average 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 lookup table, then use 
the next lowest table value. (Note: If your average 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 process units. 
Identify the appropriate maximum allowable toxicity-weighted 
noncarcinogen emission rate from Table 4 to this appendix for your 
affected source using the average 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 lookup table, then use 
the next lowest table value. (Note: If your average 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 www.epa.gov/ttn/atw.
    (b) At a minimum, you 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 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

[[Page 46042]]

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 test methods specified in Table 2 to this appendix, 
including a description of the process parameters identified as 
being worst case.
    (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, annual 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 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 (5) of this section.
    (1) Identification of the stack heights for each emission point 
included in the calculation of average 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 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 via e-
mail to [email protected] or via 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) If you have an existing affected source, you must complete 
and submit for approval your low-risk demonstration no later than 
July 31, 2006.
    (b) 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 no 
later than July 31, 2006. 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 no later than 12 months after you become a major 
source or after initial startup of your affected source as a major 
source, whichever is later.
    (c) If you have a new or reconstructed affected source you must 
conduct the emission tests specified in section 5 of this appendix 
upon initial startup and use the results of these emissions tests to 
complete and submit your low-risk demonstration within 180 days 
following your initial startup date. If your new or reconstructed 
affected source starts up before September 28, 2004, for EPA to find 
that you are included in the low-risk subcategory, your low-risk 
demonstration must show that you were eligible to meet the criteria 
in section 11 of this appendix no later than September 28, 2004. If 
your new or reconstructed source starts up after September 28, 2004, 
for EPA to find that you are included in the low-risk subcategory, 
your low-risk demonstration must show that you were eligible to meet 
the criteria in section 11 of this appendix upon initial startup of 
your affected source. Affected sources that are not part of the low-
risk subcategory by October 1, 2007, must comply with the 
requirements of 40 CFR part 63, subpart DDDD. Affected sources may 
not request compliance extensions from the permitting authority if 
they fail to demonstrate they are part of the low-risk subcategory 
or to request additional time to install controls to become part of 
the low-risk subcategory.

11. How Does My Affected Source Become Part of the Low-Risk Subcategory 
of PCWP Facilities?

    To be included in the low-risk subcategory, EPA must find that 
you meet the criteria in paragraphs (a) and (b) 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, annual emission rate, type of 
control devices, process parameters reflecting the emissions rates 
used for your low-risk demonstration) must be incorporated 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

[[Page 46043]]

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 annual 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 website 
(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 website 
(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 three 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.

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:
    Direct-fired process unit means a process unit that is heated by 
the passing of combustion exhaust directly through the process unit 
such that the process material is contacted by the combustion 
exhaust.
    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.
    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).
    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.
    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.
    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/m\3\) in 
air.
    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.
------------------------------------------------------------------------


[[Page 46044]]


 Table 2 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
                               ports' location and   CFR part 60,
                               the number of         appendix A (as
                               traverse points.      appropriate).
(2) Each process unit.......  Determine velocity    Method 2 in addition
                               and volumetric flow   to Method 2A, 2C,
                               rate;                 2D, 2F, or 2G in
                                                     appendix A to 40
                                                     CFR part 60 (as
                                                     appropriate).
(3) Each process unit.......  Conduct gas           Method 3, 3A, or 3B
                               molecular weight      in appendix A to 40
                               analysis.             CFR part 60.
(4) Each process unit.......  Measure moisture      Method 4 in appendix
                               content of the        A to 40 CFR part
                               stack gas.            60.
(5) Each process unit.......  Measure emissions of  NCASI Method IM/CAN/
                               the following HAP:    WP-99.02 (IBR, see
                               acetaldehyde,         40 CFR 63.14(f));
                               acrolein,\1\          OR Method 320 in
                               formaldehyde, and     appendix A to 40
                               phenol.               CFR part 63; OR
                                                     ASTM D6348-03 (IBR,
                                                     see 40 CFR
                                                     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.
(6) Each process unit.......  Measure emissions of  Method 320 in
                               benzene\1\.           appendix A to 40
                                                     CFR part 63; OR
                                                     ASTM D6348-03 (IBR,
                                                     see 40 CFR
                                                     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 press that           Measure emissions of  Method 320 in
 processes board containing    MDI.                  appendix A to 40
 MDI resin.                                          CFR part 63; OR
                                                     Conditional Test
                                                     Method (CTM) 031
                                                     which is posted on
                                                     http://www.epa.gov/ttn/emc/ctm.html
(8) Each direct-fired         Measure emissions of  Method 29 in
 process unit.                 the following HAP     appendix A to 40
                               metals: arsenic,      CFR part 60.
                               beryllium, cadmium,
                               chromium, lead,
                               manganese, and
                               nickel.
(9) 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.       enclosures as
                               Or.................   defined in Sec.
                              Determine the          63.2292).
                               percent capture       Enclosures that
                               efficiency of the     meet the definition
                               enclosure directing   of wood products
                               emissions to an add-  enclosure or that
                               on control device.    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.
(10) 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.                                       appropriate) of 40
                                                     CFR part 51,
                                                     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.
(11) Each process unit with   Establish the site-   Data from the
 a HAP control device.         specific operating    parameter
                               requirements          monitoring system
                               (including the        or THC CEMS and the
                               parameter limits or   applicable
                               THC concentration     performance test
                               limits) in Table 2    method(s).
                               to subpart DDDD.
------------------------------------------------------------------------
\1\ If EPA approves that your process unit will not emit detectable
  amounts of benzene or acrolein, that unit may be excluded from the
  benzene and/or acrolein (as applicable) testing requirement in this
  table.


[[Page 46045]]


      Table 3 to Appendix B to Subpart DDDD of 40 CFR part 63.--Maximum Allowable Toxicity-Weighted Carcinogen Emission Rate (lb/hr)/([mu]g/m \3\)
--------------------------------------------------------------------------------------------------------------------------------------------------------
                                                                             Distance to Nearest Residence (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
Emission rates in table expressed as equivalents normalized to theoretical HAP with URE = 1([mu]g/m3)-1


      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.
Emission rates in table expressed in lbs/hr as equivalents normalized to theoretical HAP with RfC = 1.0 [mu]g/m\3\.

PART 429--[AMENDED]

0
1. The authority citation for part 429 continues to read as follows:

    Authority: Secs. 301, 304(b), (c), (e), and (g), 306(b) and (c), 
307(a), (b), and (c) and 501 of the Clean Water Act (the Federal 
Water Pollution Control Act Amendments of 1972, as amended by the 
Clean Water Act of 1977) (the ``Act''); 33 U.S.C. 1911, 1314(b), 
(c), (e), and (g), 1316(b) and (c), 1917(b) and (c), and 1961; 86 
Stat. 815, Pub. L. 92-500; 91 Stat. 1567, Pub L. 95-217.


0
2. Section 429.11 is amended by revising paragraph (c) to read as 
follows:


Sec.  429.11  General definitions.

* * * * *
    (c) The term ``process wastewater'' specifically excludes non-
contact cooling water, material storage yard runoff (either raw 
material or processed wood storage), boiler blowdown, and wastewater 
from washout of thermal oxidizers or catalytic oxidizers, wastewater 
from biofilters, or wastewater from wet electrostatic precipitators 
used upstream of thermal oxidizers or catalytic oxidizers installed by 
facilities covered by subparts B, C, D or M to comply with the national 
emissions standards for hazardous air pollutants (NESHAP) for plywood 
and composite wood products (PCWP) facilities (40 CFR part 63, subpart 
DDDD). For the dry process hardboard, veneer, finishing, particleboard, 
and sawmills and planing mills subcategories, fire control water is 
excluded from the definition.
* * * * *
[FR Doc. 04-6298 Filed 7-29-04; 8:45 am]
BILLING CODE 6560-50-P