[Federal Register: May 16, 2003 (Volume 68, Number 95)]
[Rules and Regulations]               
[Page 26689-26755]
From the Federal Register Online via GPO Access [wais.access.gpo.gov]
[DOCID:fr16my03-16]                         


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Part II





Environmental Protection Agency





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40 CFR Part 63



National Emission Standards for Hazardous Air Pollutants for Brick and 
Structural Clay Products Manufacturing; and National Emission Standards 
for Hazardous Air Pollutants for Clay Ceramics Manufacturing; Final 
Rule


[[Page 26690]]


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ENVIRONMENTAL PROTECTION AGENCY

40 CFR Part 63

[OAR-2002-0054 and OAR-2002-0055, FRL-7459-9]
RIN 2060-A167 and 2060-A168

 
National Emission Standards for Hazardous Air Pollutants for 
Brick and Structural Clay Products Manufacturing; and National Emission 
Standards for Hazardous Air Pollutants for Clay Ceramics Manufacturing

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 new and existing sources at brick 
and structural clay products (BSCP) manufacturing facilities and NESHAP 
for new and existing sources at clay ceramics manufacturing facilities. 
This action will implement section 112(d) of the Clean Air Act (CAA) by 
requiring major sources to meet hazardous air pollutant (HAP) emission 
standards reflecting the application of the maximum achievable control 
technology (MACT). The two subparts will protect air quality and 
promote the public health by reducing emissions of several of the HAP 
listed in section 112(b)(1) of the CAA. The rules will reduce HAP 
emissions from existing sources by 2,300 tons per year nationwide, with 
hydrogen fluoride (HF) and hydrogen chloride (HCl) accounting for 2,290 
tons per year (99.6 percent) of the total HAP emissions reductions from 
existing sources. The associated metals (antimony, arsenic, beryllium, 
cadmium, chromium, cobalt, mercury, manganese, nickel, lead, and 
selenium) reductions from existing sources account for approximately 6 
tons per year nationwide (0.4 percent). Exposure to these substances 
has been demonstrated to cause adverse health effects such as 
irritation of the lung, skin, and mucus membranes, effects on the 
central nervous system, and kidney damage. The EPA has classified three 
of the HAP as known human carcinogens, four as probable human 
carcinogens, and one as a possible human carcinogen. We estimate that 
the two subparts will reduce nationwide emissions of HAP from these 
facilities by approximately 2,100 megagrams per year (Mg/yr)(2,300 tons 
per year (tpy)), a reduction of approximately 35 percent from the 
current level of emissions.

EFFECTIVE DATE: The final rule is effective May 16, 2003.

ADDRESSES: Docket No. OAR-2002-0054 contains supporting documentation 
used in developing the final BSCP rule. Docket No. OAR-2002-0055 
contains supporting documentation used in developing the final clay 
ceramics rule. The dockets are located at the Air and Radiation Docket 
and Information Center in the EPA Docket Center, (EPA/DC) EPA West, 
Room B102, 1301 Constitution Avenue, NW., Washington, DC 20460, 
telephone (202) 566-1744. The dockets are available for public 
inspection from 8:30 a.m. to 4:30 p.m., Monday through Friday, 
excluding Federal holidays.

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 rules, contact Ms. Mary Johnson, Combustion Group, Emission 
Standards Division (MC-C439-01), U.S. EPA, Research Triangle Park, 
North Carolina 27711, telephone number (919) 541-5025, e-mail address: 
johnson.mary@epa.gov.
SUPPLEMENTARY INFORMATION: Regulated Entities. Entities potentially 
regulated by this action are those industrial facilities that 
manufacture BSCP and clay ceramics. Brick and structural clay products 
manufacturing is classified under Standard Industrial Classification 
(SIC) codes 3251, Brick and Structural Clay Tile; 3253, Ceramic Wall 
and Floor Tile; and 3259, Other Structural Clay Products. The North 
American Industry Classification System (NAICS) codes for BSCP 
manufacturing are 327121, Brick and Structural Clay Tile; 327122, 
Ceramic Wall and Floor Tile Manufacturing; and 327123, Other Structural 
Clay Products. Clay ceramics manufacturing is classified under SIC 
codes 3253, Ceramic Wall and Floor Tile; and 3261, Vitreous Plumbing 
Fixtures (Sanitaryware). The NAICS codes for clay ceramics 
manufacturing are 327122, Ceramic Wall and Floor Tile Manufacturing; 
and 327111, Vitreous China Plumbing Fixture and China and Earthenware 
Bathroom Accessories Manufacturing. Regulated categories and entities 
are shown in Table 1 of this preamble.

               Table 1.--Regulated Categories and Entities
------------------------------------------------------------------------
                                                 Examples of potentially
            Category              SIC    NAICS      regulated entities
------------------------------------------------------------------------
Industrial.....................   3251   327121  Brick and structural
                                                  clay tile
                                                  manufacturing
                                                  facilities (BSCP
                                                  NESHAP)
Industrial.....................   3253   327122  Ceramic wall and floor
                                                  tile manufacturing
                                                  facilities (Clay
                                                  Ceramics NESHAP) and
                                                  extruded tile
                                                  manufacturing
                                                  facilities (BSCP
                                                  NESHAP).
Industrial.....................   3259   327123  Other structural clay
                                                  products manufacturing
                                                  facilities (BSCP
                                                  NESHAP)
Industrial.....................   3261   327111  Vitreous plumbing
                                                  fixtures
                                                  (sanitaryware)
                                                  manufacturing
                                                  facilities (Clay
                                                  Ceramics NESHAP).
------------------------------------------------------------------------

    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.  63.8385 of 
today's final BSCP rule and Sec.  63.8535 of today's final clay 
ceramics 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.
    Electronic Docket (E-Docket). The EPA has established official 
public dockets for this action under Docket ID No. OAR-2002-0054 for 
the final BSCP rule and Docket ID No. OAR-2002-0055 for the final clay 
ceramics rule. The official public dockets are the collection of 
materials that is available for public viewing at the EPA Docket Center 
(Air Docket), EPA West, Room B102, 1301 Constitution Avenue, NW., 
Washington, DC 20460. The Docket Center is open from 8:30 a.m. to 4:30 
p.m., Monday through Friday, excluding legal holidays. The telephone 
number for the Reading Room is (202) 566-1744, and the telephone number 
for the Air Docket is (202) 566-1742. A reasonable fee may be charged 
for copying docket materials.
    Electronic Access. Electronic versions of the public dockets are 
available through EPA's electronic public docket

[[Page 26691]]

and comment system, EPA Dockets. You may use EPA Dockets at http://www.epa.gov/edocket/
 to view public comments, access the indexes of the 
contents of the official public dockets, and to access those documents 
in the public dockets that are available electronically. Once in the 
system, select ``search'' and key in the appropriate docket 
identification number. 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 in 
this document.
    Worldwide Web (WWW). In addition to being available in the dockets, 
an electronic copy of today's document also will be available on the 
WWW. Following the Administrator's signature, a copy of this action 
will be posted at www.epa.gov/ttn/oarpg on EPA's Technology Transfer 
Network (TTN) policy and guidance page for newly proposed or 
promulgated rules. The TTN provides information and technology exchange 
in various areas of air pollution control. If more information 
regarding the TTN is needed, call the TTN HELP line at (919) 541-5384.
    Judicial Review. Under section 307(b)(1) of the CAA, judicial 
review 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 July 15, 2003. 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. Moreover, under section 307(b)(2) of the CAA, 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. Background
    A. What Is the Source of Authority for Development of NESHAP?
    B. What Criteria Are Used in the Development of NESHAP?
    C. How Were the Final Rules Developed?
    D. What Are the Health Effects of Pollutants Emitted From the 
Brick and Structural Clay Products Manufacturing and Clay Ceramics 
Manufacturing Source Categories?
II. Summary of Responses to Major Comments and Changes to the Brick 
and Structural Clay Products Manufacturing Proposed NESHAP
    A. Air Pollution Control Devices
    B. Affected Source
    C. Existing Source MACT
    D. New Source MACT
    E. Cost and Economic Impacts
    F. Test Data and Emission Limits
    G. Monitoring Requirements
    H. Startup, Shutdown, and Malfunction
    I. Risk-Based Approaches
III. Summary of the Final Brick and Structural Clay Products 
Manufacturing NESHAP
    A. What Source Category Is Regulated by the Final Rule?
    B. What Are the Affected Sources?
    C. When Must I Comply With the Final Rule?
    D. What Are the Emission Limits?
    E. What Are the Operating Limits?
    F. What Are the Performance Test and Initial Compliance 
Requirements?
    G. What Are the Continuous Compliance Requirements?
    H. What Are the Notification, Recordkeeping, and Reporting 
Requirements?
IV. Summary of Environmental, Energy, and Economic Impacts for the 
Final Brick and Structural Clay Products Manufacturing NESHAP
    A. What Are the Air Quality Impacts?
    B. What Are the Water and Solid Waste Impacts?
    C. What Are the Energy Impacts?
    D. Are There any Additional Environmental and Health Impacts?
    E. What Are the Cost Impacts?
    F. What Are the Economic Impacts?
V. Summary of Responses to Major Comments and Changes to the Clay 
Ceramics Manufacturing Proposed NESHAP
    A. Affected Source
    B. Existing Source MACT
    C. New Source MACT
    D. Cost and Economic Impacts
    E. Test Data and Emission Limits
    F. Monitoring Requirements
    G. Startup, Shutdown, and Malfunction
VI. Summary of the Final Clay Ceramics Manufacturing NESHAP
    A. What Source Category Is Regulated by the Final Rule?
    B. What Are the Affected Sources?
    C. When Must I Comply With the Final Rule?
    D. What Are the Emission Limits?
    E. What Are the Operating Limits?
    F. What Are the Work Practice Standards?
    G. What Are the Performance Test and Initial Compliance 
Requirements for Sources Subject to Emission Limits?
    H. What Are the Initial Compliance Requirements for Sources 
Subject to a Work Practice Standard?
    I. What Are the Continuous Compliance Requirements for Sources 
Subject to Emission Limits?
    J. What Are the Continuous Compliance Requirements for Sources 
Subject to a Work Practice Standard?
    K. What Are the Notification, Recordkeeping, and Reporting 
Requirements for Sources Subject to Emission Limits?
    L. What Are the Notification, Recordkeeping, and Reporting 
Requirements for Sources Subject to a Work Practice Standard?
VII. Summary of Environmental, Energy, and Economic Impacts for the 
Final Clay Ceramics Manufacturing NESHAP
    A. What Are the Air Quality Impacts?
    B. What Are the Water and Solid Waste Impacts?
    C. What Are the Energy Impacts?
    D. Are there any Additional Environmental and Health Impacts?
    E. What Are the Cost Impacts?
    F. What Are the Economic Impacts?
VIII. Statutory and Executive Order Reviews
    A. Executive Order 12866, Regulatory Planning and Review
    B. Paperwork Reduction Act
    C. Regulatory Flexibility Act
    D. Unfunded Mandates Reform Act
    E. Executive Order 13132, Federalism
    F. Executive Order 13175, Consultation and Coordination With 
Indian Tribal Governments
    G. Executive Order 13045, Protection of Children From 
Environmental Health & Safety Risks
    H. Executive Order 13211, Actions Concerning Regulations That 
Significantly Affect Energy Supply, Distribution, or Use
    I. National Technology Transfer and Advancement Act
    J. Congressional Review Act

I. Background

A. What Is the Source of Authority for Development of NESHAP?

    Section 112 of the CAA requires us to list categories and 
subcategories of major and area sources of HAP and to establish NESHAP 
for the listed source categories and subcategories. Clay products 
manufacturing was listed as a category of major sources on the initial 
source category list published in the Federal Register on July 16, 1992 
(57 FR 31576). In the July 22, 2002 Federal Register notice (67 FR 
47894) that proposed NESHAP for BSCP manufacturing and clay ceramics 
manufacturing, the clay products manufacturing source category was 
replaced by the BSCP manufacturing source category and the clay 
ceramics manufacturing source category. Today's action contains final 
rules for the two source categories. Major sources of HAP are those 
stationary sources or groups of stationary sources that are located 
within a contiguous area and under common control that emit or have the 
potential to emit considering controls, in the aggregate, 9.07 Mg/yr 
(10 tpy) or more of any one HAP or 22.68 Mg/yr (25 tpy) or more of any 
combination of HAP. Area sources are those stationary sources that are 
not major sources.

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

    Section 112 of the CAA requires that we establish NESHAP for the 
control of HAP from both new and existing major

[[Page 26692]]

sources. 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 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 standards are set at a level that assures that 
all major sources achieve the 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 for which the 
Administrator has emissions information (or the best-performing 5 
sources for which the Administrator has or could reasonably obtain 
emissions information for categories or subcategories with fewer than 
30 sources).
    In developing MACT, we also consider 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 health and environmental impacts, and energy 
requirements.

C. How Were the Final Rules Developed?

    We proposed standards for BSCP manufacturing and clay ceramics 
manufacturing on July 22, 2002 (67 FR 47894). 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 July 22, 2002 to September 20, 2002. 
Industry representatives, regulatory agencies, environmental groups, 
and the general public were given the opportunity to comment on the 
proposed rules and to provide additional information during the public 
comment period. We also offered at proposal the opportunity for oral 
presentation of data, views, or arguments concerning the proposed 
rules. A public hearing on the proposed BSCP rule was held on August 
21, 2002, during which 21 presentations were made. Following the public 
hearing, we met with representatives of industry and environmental 
groups on several occasions.
    We received a total of 80 public comment letters on the proposed 
BSCP rule and 9 public comments letters on the proposed clay ceramics 
rule. Comments were submitted by industry trade associations, BSCP and 
clay ceramics manufacturing companies, State regulatory agencies and 
their representatives, and environmental groups. Today's final rules 
reflect our consideration of all of the comments received. Major public 
comments on the proposed rules, along with our responses to those 
comments, are summarized in this preamble.

D. What Are the Health Effects of Pollutants Emitted From the Brick and 
Structural Clay Products Manufacturing and Clay Ceramics Manufacturing 
Source Categories?

    Today's proposed rules protect air quality and promote the public 
health by reducing emissions of some of the HAP listed in section 
112(b)(1) of the CAA. Emissions data collected during development of 
the proposed rules show that HF, HCl, and small amounts of metals 
(antimony, arsenic, beryllium, cadmium, chromium, cobalt, mercury, 
manganese, nickel, lead, and selenium) are emitted from BSCP and clay 
ceramics manufacturing facilities. Exposure to these HAP is associated 
with a variety of adverse health effects. These adverse health effects 
include chronic health disorders (e.g., irritation of the lung, skin, 
and mucus membranes, effects on the central nervous system, and damage 
to the kidneys), and acute health disorders (e.g., lung irritation and 
congestion, alimentary effects such as nausea and vomiting, and effects 
on the kidney and central nervous system). We have classified three of 
the HAP as human carcinogens, four as probable human carcinogens, and 
one as a possible human carcinogen. We do not know the extent to which 
the adverse health effects described above occur, or if any adverse 
effects occur, in the populations surrounding these facilities. 
However, to the extent the adverse effects do occur, today's proposed 
rules would reduce emissions and subsequent exposures. The majority of 
the emissions reductions from this rule are HF (1900 tons per year 
nationwide) and HCl (390 tons per year nationwide), while the rule will 
only reduce emissions of the HAP metals listed below by a small amount 
(approximately 6 tons nationwide per year).
1. Hydrogen Fluoride
    Acute (short-term) inhalation exposure to gaseous HF can cause 
severe respiratory damage in humans, including severe irritation and 
pulmonary edema. Chronic (long-term) exposure to fluoride at low levels 
has a beneficial effect of dental cavity prevention and may also be 
useful for the treatment of osteoporosis. Exposure to higher levels of 
fluoride may cause dental fluorosis or mottling, while very high 
exposures through drinking water or air can result in crippling 
skeletal fluorosis. One study reported menstrual irregularities in 
women occupationally exposed to fluoride. We have not classified HF for 
carcinogenicity.
2. Hydrogen Chloride
    Hydrogen chloride, also called hydrochloric acid, is corrosive to 
the eyes, skin, and mucous membranes. Acute (short-term) inhalation 
exposure may cause eye, nose, and respiratory tract irritation and 
inflammation and pulmonary edema in humans. Chronic (long-term) 
occupational exposure to HCl has been reported to cause gastritis, 
bronchitis, and dermatitis in workers. Prolonged exposure to low 
concentrations may also cause dental discoloration and erosion. No 
information is available on the reproductive or developmental effects 
of HCl in humans. In rats exposed to HCl by inhalation, altered estrus 
cycles have been reported in females and increased fetal mortality and 
decreased fetal weight have been reported in offspring. We have not 
classified HCl for carcinogenicity.
3. Antimony
    Acute (short-term) exposure to antimony by inhalation in humans 
results in effects on the skin and eyes. Respiratory effects, such as 
inflammation of the lungs, chronic bronchitis, and chronic emphysema, 
are the primary effects noted from chronic (long-term) exposure to 
antimony in humans via inhalation. Human studies are inconclusive 
regarding antimony exposure and cancer, while animal studies have 
reported lung tumors in rats exposed to antimony trioxide via 
inhalation. Effects of oral exposure to antimony are not well-
described, but a single study has reported decreased longevity and 
changes in serum glucose and cholesterol in rats. We have not 
classified antimony for carcinogenicity.
4. Arsenic
    Acute (short-term) high-level inhalation exposure to arsenic dust 
or fumes has resulted in gastrointestinal effects (nausea, diarrhea, 
abdominal

[[Page 26693]]

pain), and central and peripheral nervous system disorders. 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, such as spontaneous abortions. Inorganic arsenic exposure in 
humans by the inhalation route has been shown to be strongly associated 
with lung cancer, while ingestion of inorganic arsenic in humans has 
been linked to a form of skin cancer and also to bladder, liver, and 
lung cancer. We have classified inorganic arsenic as a Group A, human 
carcinogen.
5. Beryllium
    Acute (short-term) inhalation exposure to high levels of beryllium 
has been observed to cause inflammation of the lungs or acute 
pneumonitis (reddening and swelling of the lungs) in humans; after 
exposure ends, these symptoms may be reversible. 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. Oral 
exposure to beryllium was found to cause stomach lesions in dogs, but 
effects on humans are not well-described. We have classified beryllium 
as a Group B1, probable human carcinogen, when inhaled; data are 
inadequate to determine whether beryllium is carcinogenic when 
ingested.
6. Cadmium
    The acute (short-term) effects of cadmium inhalation in humans 
consist mainly of effects on the lung, such as pulmonary irritation. 
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 in animals, 
resulting in fetal malformations and other effects, but no conclusive 
evidence exists in humans. An association between cadmium inhalation 
exposure and an increased risk of lung cancer has been reported from 
human studies, but these studies are inconclusive due to confounding 
factors. 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.
7. Chromium
    Chromium may be emitted in two forms, trivalent chromium (chromium 
III) or hexavalent chromium (chromium VI). The respiratory tract is the 
major target organ for chromium VI toxicity, for acute (short-term) and 
chronic (long-term) inhalation exposures. Shortness of breath, 
coughing, and wheezing have been reported from acute exposure to 
chromium VI, while perforations and ulcerations of the septum, 
bronchitis, decreased pulmonary function, pneumonia, and other 
respiratory effects have been noted from chronic 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. Oral 
exposure of humans to chromium VI has been reported to cause sores in 
the mouth, gastrointestinal effects, and elevated white blood cell 
counts. Animal studies of oral chromium VI exposure have reported 
testicular degeneration and fetal damage in mice and rats. Chromium IV 
is also a potent contact sensitizer, producing allergic dermatitis in 
previously-exposed humans. Data are inadequate to determine if chromium 
VI is carcinogenic by oral exposure.
    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.
8. Cobalt
    Acute (short-term) exposure to high levels of cobalt by inhalation 
in humans and animals results in respiratory effects such as a 
significant decrease in ventilatory function, congestion, edema, and 
hemorrhage of the lung. Respiratory effects are also the major effects 
noted from chronic (long-term) exposure to cobalt by inhalation, with 
respiratory irritation, wheezing, asthma, pneumonia, and fibrosis 
noted. Cardiac effects, congestion of the liver, kidneys, and 
conjunctiva, and immunological effects have also been associated with 
cobalt inhalation in humans. Cobalt is an essential element in humans, 
as a constituent of vitamin B12, but excessive oral intake has been 
reported to damage the heart, and to cause gastrointestinal effects and 
contact dermatitis. Human and animal studies are inconclusive with 
respect to potential carcinogenicity of cobalt. We have not classified 
cobalt for carcinogenicity.
9. Mercury
    Mercury exists in three forms: Elemental mercury, inorganic mercury 
compounds (primarily mercuric chloride), and organic mercury compounds 
(primarily methylmercury). Each form exhibits different health effects. 
Brick, structural clay products, and clay ceramics manufacturing may 
release elemental or inorganic mercury, but not methylmercury. However, 
elemental and inorganic mercury are deposited on surface water, where 
they are converted to methylmercury, an important food contaminant.
    Acute (short-term) exposure to high levels of elemental mercury in 
humans results in central nervous system (CNS) effects such as tremors, 
mood changes, and slowed sensory and motor nerve function. High 
inhalation exposures can also cause kidney damage and effects on the 
gastrointestinal tract and respiratory system. Chronic (long-term) 
inhalation exposure to elemental mercury in humans also affects the 
CNS, with effects such as increased excitability, irritability, 
excessive shyness, and tremors. Data on toxic effects of oral exposure 
to elemental mercury are sparse. We have not classified elemental 
mercury for carcinogenicity.
    Acute exposure to inorganic mercury by the oral route may result in 
effects such as nausea, vomiting, and severe abdominal pain. The major 
effect from chronic exposure, either oral or inhalation, to inorganic 
mercury is kidney damage. Reproductive and developmental animal studies 
have reported effects such as alterations in

[[Page 26694]]

testicular tissue, increased embryo resorption rates, and abnormalities 
of development. Mercuric chloride (an inorganic mercury compound) 
exposure has been shown to result in forestomach, thyroid, and renal 
tumors in experimental animals. We have classified mercuric chloride as 
a Group C, possible human carcinogen.
    Both acute and chronic oral exposure to methylmercury have been 
found to cause developmental damage to the central nervous system in 
fetuses and children, with effects including mental retardation, 
deafness, blindness, and cerebral palsy. Lower exposures may cause 
developmental delays and abnormal reflexes. The most important source 
of methylmercury exposure for most people is eating fish. Although fish 
is an important part of a balanced diet federal and state fish 
advisories recommend limiting intake of certain fish that contain 
elevated methylmercury levels.
10. 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 
CNS effects. Visual reaction time, hand steadiness, and eye-hand 
coordination were affected in chronically-exposed workers. Manganism, 
characterized by feelings of weakness and lethargy, tremors, a mask-
like face, and psychological disturbances, may result from chronic 
exposure to higher levels. Impotence and loss of libido have been noted 
in male workers afflicted with manganism attributed to inhalation 
exposures. We have classified manganese as Group D, not classifiable as 
to human carcinogenicity.
11. 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. 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. Dermal exposure to nickel may produce 
contact dermatitis. Adverse effects of oral nickel exposure are not 
well-described. 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.
12. Lead
    Lead is a very toxic element, causing a variety of effects at low 
oral or inhaled dose levels. Brain damage, kidney damage, and 
gastrointestinal distress may occur from acute (short-term) exposure to 
high levels of lead in humans. Chronic (long-term) exposure to 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.
13. Selenium
    Selenium is a naturally occurring substance that is toxic at high 
concentrations but is also a nutritionally essential element. Acute 
(short-term) exposure to elemental selenium, hydrogen selenide, and 
selenium dioxide by inhalation results primarily in respiratory 
effects, such as irritation of the mucous membranes, pulmonary edema, 
severe bronchitis, and bronchial pneumonia. Studies of humans 
chronically (long-term) exposed to high levels of selenium in food and 
water have reported discoloration of the skin, pathological deformation 
and loss of nails, loss of hair, excessive tooth decay and 
discoloration, lack of mental alertness, and listlessness. The 
consumption of high levels of selenium by pigs, sheep, and cattle has 
been shown to interfere with normal fetal development and to produce 
birth defects. Results of human and animal studies suggest that 
supplementation with some forms of selenium may result in a reduced 
incidence of several tumor types. One selenium compound, selenium 
sulfide, is carcinogenic in animals exposed orally. We have classified 
elemental selenium as a Group D, not classifiable as to human 
carcinogenicity, and selenium sulfide as a Group B2, probable human 
carcinogen.

II. Summary of Responses to Major Comments and Changes to the Brick and 
Structural Clay Products Manufacturing Proposed NESHAP

    In response to the public comments received on the proposed BSCP 
rule, we made several changes in developing today's final BSCP rule. 
The major comments and our responses and rule changes are summarized in 
the following sections. A more detailed summary can be found in the 
Response-to-Comments document, which is available from several sources 
(see SUPPLEMENTARY INFORMATION section).

A. Air Pollution Control Devices

    The most significant change to the proposed BSCP rule concerns our 
conclusions regarding the effective application of air pollution 
control devices (APCD) to existing kilns. The EPA received numerous 
comments from industry representatives, kiln manufacturers, and air 
pollution control device vendors on issues related to the application 
and performance of APCD. The MACT floor in the proposed rule was based 
on the use of dry lime injection fabric filters (DIFF), dry lime 
scrubber/fabric filters (DLS/FF), or wet scrubbers (WS). Another 
technology commonly used to control emissions from brick kilns, dry 
limestone adsorbers (DLA), was not considered to be a MACT floor 
technology at the time of proposal because we had concerns with 
monitoring options and our data indicated that the DLA could not 
achieve HAP emissions reductions equivalent to the reductions achieved 
by DIFF, DLS/FF, or WS technologies. However, as discussed in the 
paragraphs below, many commenters reported disadvantages of the DIFF, 
DLS/FF, and WS technologies for BSCP kilns and provided information to 
address our concerns about DLA technology. Consequently, the final rule 
allows some sources to use the DLA technology.
    Several commenters argued that DIFF, DLS/FF, and WS technologies 
are not proven or commercially available for BSCP kilns. Commenters 
pointed out that, with the exception of one facility, full-scale WS 
have never been used on

[[Page 26695]]

BSCP kilns, although some short-term pilot tests of WS have been 
conducted. The commenters pointed out that injection systems (such as 
DIFF and DLS/FF) and wet control devices need a certain airflow to 
operate properly, and different products may require different 
airflows, some of which could be outside of the range within which the 
APCD operates properly. In addition, commenters pointed out that during 
kiln slowdowns (which could be caused by a situation such as an 
economic slowdown), the APCD may not be able to operate at all because 
of reduced kiln airflow.
    Several commenters expressed concerns about waste disposal. 
Commenters stated that DIFF and DLS/FF systems produce large amounts of 
solid waste that is difficult and expensive to dispose of. Commenters 
stated that WS would not be viable options for many BSCP plants because 
of wastewater treatment issues (e.g., limited or no sewer access, 
wastewater treatment costs). Commenters added that recycling of WS 
wastewater back into the brick body is not an option because of 
problems created by the soluble salts in the water (e.g., scumming and 
efflorescence) and because the volume of wastewater generated would 
exceed process water needs even if recycling were possible.
    Commenters also raised concerns about retrofitting existing BSCP 
kilns with DIFF, DLS/FF, and WS technologies. Commenters pointed out 
that brick color, the primary factor in brick sales, is affected by 
kiln airflow. Thus, retrofitting with an APCD that changes the kiln 
airflow would change the recipes for the manufacture of brick in a 
tunnel kiln. Thus, years of experience in the colors produced by the 
unique firing characteristics of a kiln would be lost. Implications are 
serious if a facility cannot match its existing product line.
    The commenters also charged that we did not account for other 
retrofitting problems associated with installing DIFF, DLS/FF, or WS on 
older kilns, and the costs associated with these problems. Commenters 
also described how attempts at retrofitting kilns with these APCD have 
resulted in significant amounts of kiln downtime and permanent 
reductions in kiln production capacities. As stated by the commenters, 
none of the retrofits have been entirely successful in terms of 
reducing emissions while not disrupting the production process, and 
several have had dramatic negative impacts on the production process. 
At one facility that retrofitted two kilns with DIFF, the capacities of 
the two kilns decreased from 13.5 cars per day to 12.2 cars per day 
because of changes in the kiln airflow that resulted from the retrofit. 
This resulted in a loss of revenue of about $1 million per year. 
Another retrofit DIFF (multi-stage injection system) installation at a 
different facility was reported to be extremely problematic, and the 
cost of the APCD, which was originally estimated at $1 million, is now 
over $2 million and the system is still not operating correctly more 
than 2 years later. The facility has experienced numerous problems with 
the basic design of the unit, including improperly designed dampers and 
reagent feeding systems. A facility representative stated that the 
problems are largely due to the fact that few systems have been 
developed for brick kiln operations; therefore, vendors are still 
learning (often on the industry's nickel) how to design these systems. 
In the facility's public comments, they stated that they plan to never 
build another hot baghouse (DIFF or DLS/FF) due to the massive 
operating problems associated with them. A retrofit DLS/FF system, the 
only one that has been attempted in the U.S. to date, also was 
problematic. The facility stated that they have experienced maintenance 
and material quality problems that have resulted in kiln downtime. The 
facility added that the problems stem from the fact that the system is 
a prototype without a substantial operational, troubleshooting and 
maintenance history, which has left the facility in the position of 
having to diagnose and solve the problems as the system operates. In 
addition, the company that installed this system is no longer quoting 
systems to the BSCP industry.
    Numerous commenters recommended that EPA allow use of DLA. The 
commenters described the operating benefits of DLA, including ease of 
operation, low operating cost, little down time, and the ability to 
handle kiln fluctuations with changing throughputs. Most importantly, 
DLA do not impact kiln operation. The commenters pointed out that DLA 
do not require a minimum airflow like DIFF, DLS/FF, or WS technologies. 
One commenter pointed out that once a DLA is designed for maximum 
airflow, any fluctuations below this maximum only create more contact 
time between the kiln exhaust gases and the limestone, which would 
likely increase the effectiveness of the DLA and would not impact the 
operation of the kiln. The commenters pointed out that DLA have been 
used extensively in Europe for many years and also are the most 
prevalent APCD used in the BSCP industry in the United States. Many 
commenters stated that DLA should be allowed if they can meet the BSCP 
standards. The commenters indicated that plants should not have to 
request site-specific monitoring parameters for DLA because they are 
the most prevalent technology. In addition, some commenters discussed 
the high costs and limited additional HAP reduction associated with 
replacing existing DLA with a DIFF system.
    Several commenters felt that EPA disregarded or ``bashed'' DLA and 
disagreed with EPA's conclusions regarding DLA in the preamble to the 
proposed rule. Specifically, the commenters disagreed that: DLA 
generate particulate matter (PM) emissions; long-term test data that 
demonstrate DLA performance over the life of the sorbent are not 
available; DLA limestone is not continuously replaced; and the 
performance of DLA decreases as the sorbent is re-used because the 
ability of the sorbent to adsorb HF and HCl decreases.
    We disagree with commenters that the use of DIFF has not been 
proven in the brick industry. The DIFF and DLS/FF systems are a proven 
control technology for kilns with a given minimum airflow rate. We do, 
however, believe that retrofitting existing kilns with DIFF or DLS/FF 
systems is not feasible in many cases. We recognize that WS may not be 
practical or low-cost for most facilities, but believe they could be a 
legitimate option for some facilities (e.g., facilities with sewer 
access). We acknowledge that retrofitting existing BSCP kilns with 
certain APCD (particularly those that affect kiln airflow) can alter 
time-honored recipes for brick color, thereby changing the product. We 
acknowledge that DLA are used extensively around the world to control 
emissions from brick kilns. In developing the description of DLA 
technology for the preamble to the proposed rule, we used the technical 
data available to us at the time. We had no intention of ``bashing'' 
DLA but simply reported the data at hand.
    After consideration of the comments received regarding DIFF, DLS/
FF, WS, and DLA technologies, we have come to new conclusions regarding 
the effective application of these devices. We now believe that DLA are 
the only currently available technology that can be used to retrofit 
existing kilns without potentially significant impacts on the 
production process, and we have revised today's final rule accordingly. 
In addition, we believe that, because of the retrofit concerns that we 
have identified, it is not technologically and economically feasible 
for an existing

[[Page 26696]]

small tunnel kiln that would otherwise meet the criteria for 
reconstruction in 40 CFR 63.2 and whose design capacity is increased 
such that it is equal to or greater than 9.07 Mg/hr (10 tph) of fired 
product (for the remainder of this preamble, these sources will be 
referred to as ``existing small kilns that are rebuilt such that they 
become large kilns'') to meet the relevant standards (i.e., new source 
MACT) by retrofitting with a DIFF, DLS/FF, or WS. In addition, we 
believe that it is not technologically and economically feasible for an 
existing large DLA-controlled kiln that would otherwise meet the 
criteria for reconstruction in 40 CFR 63.2 (for the remainder of this 
preamble, these sources will be referred to as ``existing large DLA-
controlled kilns that are rebuilt'') to meet the relevant (i.e., new 
source MACT) standards by retrofitting with a DIFF, DLS/FF, or WS. 
Accordingly, we have added regulatory language in 40 CFR 63.8390(i) to 
provide that an existing small kiln that is rebuilt such that it 
becomes a large kiln and an existing large DLA-controlled tunnel kiln 
that is rebuilt do not meet the definition of reconstruction in 40 CFR 
63.2 and are not subject to the same requirements as new and 
reconstructed large tunnel kilns. However, it is technologically and 
economically feasible for both types of kilns described in 40 CFR 
63.8390(i) to retrofit with a DLA (or to continue operating an existing 
DLA) and we have revised today's final rule to require that such kilns 
meet emission limits that correspond to the level of control provided 
by a DLA. We continue to believe that DIFF, DLS/FF, and WS are 
appropriate technologies for new large tunnel kilns and for 
reconstructed large tunnel kilns that were equipped with DIFF, DLS/FF, 
or WS prior to reconstruction. However, DLA are the only APCD that have 
been demonstrated on small tunnel kilns (which have smaller airflows 
than large tunnel kilns), and, therefore, the requirements for new and 
reconstructed small tunnel kilns are based on the level of control that 
can be achieved by a DLA. We note that facilities have the flexibility 
to select any control device or technique that ensures that emissions 
from their brick kilns are in compliance with the emission limits set 
forth in the final rule. Each of the APCD described above have 
advantages and disadvantages to their use, and the selection of the 
APCD to meet the requirements of the final rule will be dependent on 
site-specific parameters.

B. Affected Source

1. Production-Rate Limit
    The proposed rule subcategorized tunnel kilns based on a 9.07 Mg/hr 
(10 tph) design capacity. We requested comment on the appropriate 
design capacity-based subcategorization level in the preamble to the 
proposed rule. We received numerous comments regarding 
subcategorization of tunnel kilns. While some commenters agreed with 
the 9.07 Mg/hr (10 tph) distinction among tunnel kiln subcategories, 
several commenters thought that the 9.07 Mg/hr (10 tph) limit was 
arbitrarily assigned. The commenters charged that EPA did not use all 
available data in determining the appropriate size cutoff. Many 
commenters argued that the design capacity limit should be higher based 
on available data (i.e., 10.1 Mg/hr (11.1 tph) or 12.1 Mg/hr (13.3 
tph)). The commenters disagreed that the cutoff should be rounded down 
from 10.1 Mg/hr (11.1 tph) to 9.07 Mg/hr (10 tph).
    Some commenters noted that a design capacity distinction gives a 
competitive advantage to facilities operating smaller kilns. One 
commenter disagreed that there was a technological basis for 
differentiating among tunnel kilns producing above or below 9.07 Mg/hr 
(10 tph). The commenter stated that EPA may not subcategorize tunnel 
kilns to reduce costs.
    Through subcategorization, we are able to define subsets of similar 
emission sources within a source category if differences in emissions 
characteristics, processes, APCD viability, or opportunities for 
pollution prevention exist within the source category. Section 
112(d)(1) of the CAA states ``the Administrator may distinguish among 
classes, types, and sizes of sources within a category or subcategory'' 
in establishing emission standards. Thus, we have discretion in 
determining appropriate subcategories based on classes, types, and 
sizes of sources. We used this discretion in developing subcategories 
for the BSCP source category. We first subcategorized kilns based on 
type (i.e., periodic kilns versus tunnel kilns). We then further 
subcategorized tunnel kilns based on kiln size. Our distinctions are 
based on technological differences in the equipment. For example, 
periodic kilns are smaller than tunnel kilns and operate in batch 
cycles, whereas tunnel kilns operate continuously. There are also 
differences in the effective application of air pollution controls. To 
our knowledge, HAP emissions from periodic kilns have not successfully 
been controlled. Similarly, we distinguished between tunnel kilns with 
design capacities above and below 9.07 Mg/hr (10 tph) at proposal in 
part because the APCD we believed to be the best performers (DIFF, DLS/
FF, and WS) were not demonstrated on existing tunnel kilns with design 
capacities below roughly 9.07 Mg/hr (10 tph). For the reasons discussed 
below, we revisited the appropriate subcategorization level in response 
to comments on the proposal when developing today's final rule. While 
we continue to believe that 9.07 Mg/hr (10 tph) is the appropriate 
subcategorization level, our reasons for choosing that level have 
changed since proposal in light of new information that we received 
during the public comment period about DLA controls and the three 
proposed MACT controls (DIFF, DLS/FF, and WS).
    As discussed earlier, numerous commenters pointed out serious 
concerns regarding retrofitting existing kilns with APCD such as DIFF, 
DLS/FF, and WS. Therefore, we now consider DLA to be the only currently 
available technology that can be used to retrofit existing kilns, 
including existing small kilns that are rebuilt such that they become 
large kilns and existing large DLA-controlled kilns that are rebuilt, 
without potentially significant impacts on the production process.
    In response to comments suggesting that we include new data in our 
analyses, we updated our data base with information on new kilns, new 
APCD (except those controls that we consider to achieve the lowest 
achievable emission rate (LAER) as specified in section 112(d)(3)(A) of 
the CAA), changes in kiln capacities, and changes in facility 
ownership. We used the information submitted by commenters and made 
followup calls to States and individual facilities for additional 
clarification as necessary to update our data base.
    We used our updated data base in reevaluating all aspects of the 
proposed standards. The smallest tunnel kiln with MACT floor controls 
(i.e., with DLA controls reflecting the existing source MACT floor 
under today's final rule) in our updated database has a capacity of 8.3 
Mg/hr (9.1 tph). Rounding up to the nearest integer, based on current 
application of APCD to BSCP tunnel kilns, we believe that 9.07 Mg/hr 
(10 tph) continues to be an appropriate subcategorization level. 
Commenters have stated that a smaller tunnel kiln (e.g., 4.5 Mg/hr (5 
tph) capacity) is dissimilar from a larger tunnel kiln (e.g., 13.6 Mg/
hr (15 tph) capacity), especially with regard to the airflow, which is 
a key operating parameter for APCD. Airflow is particularly important 
for

[[Page 26697]]

lime injection-type systems (DIFF and DLS/FF), because the injected 
lime is carried through the reaction chamber (or duct) by the kiln 
exhaust gas. For a given lime injection rate, if a minimum exhaust flow 
is not maintained, the sorbent can settle in the duct work and cause 
APCD malfunction. Furthermore, APCD malfunctions can affect the airflow 
within the kiln, and can destroy product that is in the kiln. We 
believe that DIFF and DLS/FF systems, if attempted on smaller kilns, 
would experience more difficulties with respect to airflow than systems 
on larger kilns because as the design airflow decreases, the acceptable 
operating range also would be expected to decrease. Any fluctuation in 
airflow would be expected to have a greater impact on APCD operation as 
the size of the system decreases. Given the technological concerns and 
the capacities of currently-controlled tunnel kilns, we maintain that a 
design capacity-based subcategorization level of 9.07 Mg/hr (10 tph) is 
appropriate for existing tunnel kilns.
    We acknowledge the comments suggesting that 10.1 Mg/hr (11.1 tph) 
should be the size cutoff based on the smallest DIFF-controlled tunnel 
kiln. However, because we now consider that the performance of a DLA 
represents the MACT floor for existing sources (and DIFF, DLS/FF, and 
WS also can meet the emission limits), we considered the smallest non-
LAER DLA-controlled kiln in setting the subcategorization level. We 
disagree that 12.1 Mg/hr (13.3 tph) would have been the proper level 
for proposal or for the final rule. We believe that consideration of 
technological differences and the effective application of APCD to 
kilns of different sizes is the appropriate method of selecting a 
subcategorization level. We maintain that 9.07 Mg/hr (10 tph) is 
appropriate.
    We understand that, regardless of the particular subcategorization 
level selected, there will be facilities that operate kilns with 
throughputs slightly above the level and some that operate kilns at 
slightly below the level. Facilities operating kilns slightly above the 
subcategorization level have the option of accepting a federally 
enforceable permit limit to limit their throughput to below the level. 
Facilities operating just below the level must make careful decisions 
regarding expansion of their kilns. We acknowledge that facilities 
operating near the subcategorization level must make decisions 
regarding permit limits and expansions based on facility-specific 
considerations (e.g., control costs, impact on revenue). However, as 
some commenters have pointed out, cost is not an appropriate criteria 
for us to use in establishing subcategories, because our discretion for 
establishing subcategories is limited, under the CAA, to distinguishing 
among classes, types, and sizes of sources.
2. R&D Kiln Definition
    One commenter requested that we change the definition of research 
and development (R&D) kiln so that it is consistent with the definition 
of R&D in section 112(c)(7) of the CAA and most other NESHAP. 
Therefore, today's final rule includes a revised definition of research 
and development kiln that is consistent with section 112(c)(7) of the 
CAA and other NESHAP.

C. Existing Source MACT

1. Consideration of Synthetic Area Sources in the MACT Floor 
Determinations for Existing Sources
    In the preamble to the proposed BSCP rule, we requested comment on 
inclusion of synthetic area sources (also called synthetic minor 
sources) in the MACT floor determinations for existing tunnel kilns. 
For the remainder of this preamble, we will refer to these sources as 
synthetic minor sources. Synthetic minor sources are those facilities 
that emit fewer than 10 tons per year of any HAP and fewer than 25 tons 
per year of any combination of HAP because they use some emission 
control device (or devices), the operation of which is required by a 
Federally Enforceable State Operating Permit (FESOP). In the absence of 
such controls, these sources would be major.
    Inclusion of synthetic minor sources in the MACT floor 
determination was an issue prior to proposal because whether or not 
synthetic minor sources were included would affect the level of control 
represented by the floor determinations for existing large tunnel kilns 
(i.e., tunnel kilns with design capacities equal to or greater than 
9.07 Mg/hr (10 tph)). Had synthetic minor sources been excluded, the 
MACT floor for existing tunnel kilns would have been ``no emissions 
reductions.'' With synthetic minor sources included (as we proposed), 
the MACT floor for existing tunnel kilns was based on a DIFF, DLS/FF or 
WS.
    Industry representatives asserted, prior to proposal, that the BSCP 
MACT floor determination should not include synthetic minor sources. We 
rejected the idea of excluding synthetic minor sources from the MACT 
floor determination for several reasons discussed in the preamble to 
the proposed rule. (See 67 FR 47894, 47911-47912, July 22, 2002.) 
Nevertheless, because of the industry representatives' arguments, we 
requested comment from all interested parties on inclusion of synthetic 
minor sources in MACT floor determinations.
    Following proposal, numerous industry representatives commented on 
the issue of whether to include synthetic minor sources in MACT floor 
determinations. The industry representatives commented that only major 
sources are included in the listed BSCP source category, and therefore, 
only major sources are to be used in the MACT floor determination. The 
commenters referenced section 112(a)(1) of the CAA, which defines major 
source as a source that ``emits or has the potential to emit 
considering controls 10 tons per year * * *.'' (emphasis added), and 
stated that by definition, synthetic minor sources are not major 
sources. The commenters noted that EPA did not include true area 
sources (or minor sources) in the MACT floor determination and stated 
that synthetic minor sources should be treated similarly for purposes 
of establishing MACT floors.
    An environmental group also commented on the issue of including 
synthetic minor sources in MACT floor determinations. The commenter 
supported EPA's decision to include synthetic minor sources in the MACT 
floor for BSCP. The commenter stated that the CAA requires EPA to 
include synthetic minor sources in MACT floor determinations. The 
commenter stated that excluding consideration of the best-controlled 
sources (which became synthetic minor sources as a result of effective 
controls) would contradict the CAA section 112(d) MACT floor 
methodology established by Congress. The commenter argued that such 
exclusion would weaken emission standards required for existing 
sources, and increase the levels of air toxics released into the 
environment.
    Section 112(d) of the CAA directs us to establish emission 
standards for each category or subcategory of major sources and minor 
sources of HAP listed for regulation pursuant to section 112(c) of the 
CAA. Each such standard must reflect a minimum level of control known 
as the MACT floor. (See CAA section 112(d).) However, section 112 of 
the CAA does not specifically address synthetic minor or synthetic area 
sources, which include those sources that emit fewer than 10 tons per 
year of any HAP or fewer than 25 tons per year of any combination of 
HAP because they use some emission control device(s), pollution 
prevention techniques or other measures (collectively referred to as 
controls in this preamble) adopted

[[Page 26698]]

under Federal or State regulations. If not for the enforceable controls 
they have implemented, synthetic minor sources would be major sources 
under section 112 of the CAA.
    We believe that the better interpretation of the CAA's plain 
language and legislative history requires that synthetic minor sources 
be included in MACT floor determinations. First, the plain language of 
the statute makes clear that our MACT floor determinations are to 
reflect the best sources in a category. For new sources in a category 
or subcategory, the MACT floor shall not be less stringent than the 
emission control that is achieved in practice by the best-controlled 
similar source, as determined by EPA. (See CAA section 112(d)(3), 
emphasis added.) For existing sources in a category or subcategory with 
30 or more sources, the MACT floor may be less stringent than the floor 
for new sources in the same category or subcategory but shall not be 
less stringent than the average emission limitation achieved by the 
best performing 12 percent of the existing sources (for which the 
Administrator has emissions information). (See CAA section 
112(d)(3)(A), emphasis added.\1\) Thus, section 112(d)(3) of the CAA 
requires that MACT floors reflect what the best-controlled new sources 
and the best-performing existing sources achieve in practice. These 
phrases contain no exemptions and are not limited by references to 
sources with or without controls. Therefore, they suggest that all of 
the best-controlled or best-performing sources should be considered in 
MACT floor determinations, regardless of whether or not such sources 
rely upon controls.
---------------------------------------------------------------------------

    \1\ If a category or subcategory has fewer than 30 sources, the 
floor shall be ``the average emission limitation achieved by the 
best performing 5 sources (for which the Administrator has or could 
reasonably obtain emissions information) in the category or 
subcategory.'' (See CAA section 112(d)(3)(B), emphasis added.)
---------------------------------------------------------------------------

    Furthermore, section 112(d)(3) of the CAA expressly excludes 
certain sources that meet LAER requirements from MACT floor 
determinations for existing sources. (See CAA section 112(d)(3)(A).) 
The fact that Congress expressly excluded such LAER sources but did not 
also exclude synthetic minor sources suggests that no exclusion was 
intended for synthetic minor sources. Indeed, nothing in the statute 
suggests that EPA should exclude a control technology from its 
consideration of the MACT floor because the technology is so effective 
that it reduces source emissions such that the source is no longer a 
major source of HAP. (See 67 FR 36,460 and 36,464, May 23, 2002, 
stating this rationale for including synthetic minor sources in the 
floor determination for the proposed NESHAP for municipal solid waste 
landfills.)
    Some commenters argue that because the BSCP source category only 
includes major sources and synthetic minor sources are non-major by 
definition, synthetic minor sources (like true area sources) fall 
outside the regulated source category and should not be considered in 
MACT floor determinations. EPA agrees that the BSCP source category 
includes only major sources. (See 67 FR 47,894 and 47,898, July 22, 
2002.) However, EPA disagrees that the CAA contemplates that synthetic 
minor sources must be treated like true area sources and excluded from 
MACT floor determinations. Section 112(a) of the CAA defines a major 
source as:

    any stationary source or group of stationary sources located 
within a contiguous area and under common control that emits or has 
the potential to emit considering controls, in the aggregate, 10 
tons per year or more of any hazardous air pollutant or 25 tons per 
year or more of any combination of hazardous air pollutants * * *.

(See CAA section 112(a)(1).) An area source is defined as any 
stationary source of hazardous air pollutants that is not a major 
source. (See CAA section 112(a)(1).) In the major source definition, 
the reference to a source's potential to emit considering controls 
allows the interpretation that a source's potential to emit before and 
after controls is relevant, such that synthetic minor sources may be 
considered within the meaning of this definition and included in MACT 
floor determinations for categories of major sources.\2\ Some 
commenters appear to suggest that the reference to a source's potential 
to emit considering controls can only mean a source's potential to emit 
after controls have been implemented. While it is possible to read the 
phrase in this manner in isolation, this interpretation would have the 
effect of excluding the best-performing sources in a category from MACT 
floor determinations and therefore would be contrary to the statutory 
mandate that EPA set MACT floors based on the levels the best-
controlled new sources and the best-performing existing sources achieve 
in practice. We believe the statutory reference to potential to emit 
considering controls should be read in a manner consistent with the 
other requirements of section 112(d) of the CAA to allow for the 
consideration of synthetic minor sources in MACT floor determinations 
for categories of major sources.
---------------------------------------------------------------------------

    \2\ We believe this approach is not inconsistent with our policy 
that existing sources that limit their potential to emit to below 
the major source threshold prior to the first compliance deadline 
under a MACT standard will not be subject to the standard, as one 
commenter suggests. (See Memorandum from John S. Seitz, Director, 
Office of Air Quality Planning and Standards, EPA, to EPA Regions, 
``Potential to Emit for MACT Standards--Guidance on Timing Issues,'' 
May 16, 1995.) Including synthetic minor sources in MACT floor 
determinations ensures that MACT floors reflect the best-performing 
sources, as the CAA requires. At the same time, our policy 
recognizes that sources that already achieve or perform better than 
the MACT floors need not be subject to the MACT standards.
---------------------------------------------------------------------------

    In addition, the legislative history suggests that synthetic minor 
sources should be included in MACT floor determinations. In a floor 
statement, Senator Durenberger stated that in implementing section 
112(d)(3) of the CAA, ``the [Senate] managers intend the Administrator 
to take whatever steps are necessary to assure that [the Administrator] 
has collected data on all of the better-performing sources within each 
category. [The Administrator] must have a data-gathering program 
sufficient to assure that [EPA] does not miss any sources that have 
superior levels of emission control.'' (See Environment and Natural 
Resources Policy Division, Congressional Research Service, 103d Cong., 
S.Prt. 103-38 (prepared for the U.S. Senate Committee on Environment 
and Public Works), A Legislative History of the Clean Air Act 
Amendments of 1990 at 870, Nov. 1993, emphasis added.) This statement 
underscores that Congress intended for MACT floor determinations to 
reflect consideration of all of the sources in each category with the 
best emission controls. We believe it would be inconsistent with 
Congress's intent and the plain language of the CAA to exclude 
synthetic minor sources--those sources with superior controls which 
became synthetic minor sources by implementing such controls--from MACT 
floor determinations.
    We believe that the inclusion of synthetic minor sources in MACT 
floor determinations is justified because of the reasons explained 
above. Even if the MACT floor determination had been ``no emissions 
reductions'' we believe that a departure from the MACT floor to a 
beyond-the-floor standard, based on DLA technology, is viable because 
the benefits associated with the emissions reductions will exceed the 
cost of installing and operating the technology.
2. MACT Floors for Existing Sources
    Some commenters questioned how the MACT floor for existing sources 
was

[[Page 26699]]

set. Some commenters thought that control devices installed for sulfur 
oxides (SOx) control (rather than for HAP control) should 
not be considered in the MACT floor. Other commenters felt that costs 
should be a consideration.
    One commenter charged that EPA has simply set MACT floors based on 
control technology type and that EPA did not identify the relevant best 
performers and set floors reflecting their average emission level. The 
commenter noted that factors other than control device type affect 
emissions and that EPA must consider all non-negligible factors in 
setting MACT floors and considering beyond-the-floor measures. The 
commenter stated that if EPA believes it is unworkable to consider all 
factors, then perhaps EPA should base standards on actual emissions 
data which reflects all the factors influencing a source's performance. 
The commenter also noted that EPA picked the worst performance of any 
source that used the chosen technology to set the floor for PM.
    A detailed discussion of how we determined the MACT floor for 
existing large tunnel kilns (i.e., tunnel kilns with design capacities 
equal to or greater than 9.07 Mg/hr (10 tph)) is provided below. 
Although the discussion in the example below focuses on existing large 
tunnel kilns that exhaust directly to the atmosphere or to an APCD, the 
same MACT floor methodology was used for existing large tunnel kilns 
that exhaust to sawdust dryers prior to exhausting to the atmosphere, 
existing small tunnel kilns that exhaust directly to the atmosphere or 
to an APCD, existing small sawdust-fired tunnel kilns that duct to 
sawdust dryers, and existing periodic kilns. Details of these MACT 
floor determinations were discussed in the preamble to the proposed 
rule. (See 67 FR 47909-47912, July 22, 2002.) Section 112(d)(3) is the 
section of the CAA that dictates how we must establish MACT floors. 
Section 112(d)(3) of the CAA states that:

    The maximum degree of reduction in emissions that is deemed 
achievable for new sources in a category or subcategory shall not be 
less stringent than the emission control that is achieved in 
practice by the best controlled similar source, as determined by the 
Administrator. Emission standards promulgated under this subsection 
for existing sources in a category or subcategory may be less 
stringent than standards for new sources in the same category or 
subcategory but shall not be less stringent, and may be more 
stringent than--
    (A) Rhe average emission limitation achieved by the best 
performing 12 percent of the existing sources (for which the 
Administrator has emissions information), excluding those sources 
that have, within 18 months before the emission standard is proposed 
or within 30 months before such standard is promulgated, whichever 
is later, first achieved a level of emission rate or emission 
reduction which complies, or would comply if the source is not 
subject to such standard, with the lowest achievable emission rate 
(as defined by section 171) applicable to the source category and 
prevailing at the time, in the category or subcategory for 
categories and subcategories with 30 or more sources * * *.

    With the exception of the LAER provisions in section 112(d)(3)(A) 
of the CAA, the CAA requires us to base the MACT floor on the best-
performing sources without consideration of why facilities decided to 
control emissions. Therefore, if an APCD is reducing HAP emissions 
(e.g., HF, HCl, or HAP metals), it is irrelevant if sources installed 
APCD for SOX or visible emissions control for purposes of 
conducting MACT floor determinations.
    We determined the MACT floor control level for existing sources 
using the following general procedure:
    (1) We reviewed available data on pollution prevention techniques 
(including substitution of raw materials and/or fuels) and the 
performance of add-on control devices to determine the techniques that 
were viable for and effective at reducing HAP emissions;
    (2) For each subcategory, we ranked the kilns from the best 
performing to the worst performing based on the emission reduction 
technique used on the kilns;
    (3) For each subcategory, we then identified the 94th percentile 
kiln and the emission reduction technique that represented the MACT 
floor technology; and
    (4) For each subcategory, we then selected production-based or 
percent-reduction emission limits that correspond to the 94th 
percentile kiln and emission reduction technique, and we based our 
selections on the available data while considering variability in the 
performance of a given emission reduction technique.
    To identify the best-performing emission reduction techniques, we 
reviewed available data on pollution prevention techniques (i.e.,, 
substitution of raw materials and/or fuels) and the performance of add-
on control devices. We determined that substitution of raw materials 
and/or fuels is not an option because substitution of raw materials 
and/or fuels could affect the ability of a facility to duplicate its 
current product line. In addition, it is impractical for facilities to 
import, from a distance of more than a few miles, the large amounts of 
raw material that are required (most facilities are located in close 
proximity to their raw material source). With respect to use of low-HAP 
fuels, our available test data for the BSCP industry do not show 
identifiable differences in emissions based on kiln fuel type; that is, 
the contribution of raw materials to HAP emissions far outweighs the 
contribution of the fuels. In addition, fuel type can impact the color 
of a product, and any requirement that would require a kiln to change 
fuel type could cause the kiln to be unable to match an existing 
product line. While we agree that factors other than APCD type can 
affect emissions, we do not have the data to determine the specific 
degree of the effect of factors other than APCD on emissions, and we 
believe that, for the BSCP industry, factors other than APCD use are 
not viable MACT floor or beyond-the-floor control options. Our data 
show that add-on APCD have a large effect on emissions, and further 
show that the presence or absence of an APCD is likely the greatest 
factor in determining a BSCP kiln's actual performance. It follows that 
the subset of BSCP kilns that are the best performers are those with 
add-on APCD. Therefore, our analysis focused on the performance of add-
on control devices.
    Prior to proposal we concluded that the best-performing add-on 
control devices were DIFF, DLS/FF, and WS. Based on the comments 
received following proposal (as discussed elsewhere in this preamble) 
regarding retrofit concerns with these technologies, we now believe 
that DLA are the only currently available technology that can be used 
to retrofit existing large kilns without potentially significant 
impacts on the production process. Thus, DLA are the best-performing 
APCD for existing large tunnel kilns.
    We ranked the kilns within each subcategory according to APCD use. 
Information on the number of kilns and the types of APCD was based 
primarily on responses to a survey of the industry and additional 
information gathered following the survey including public comments on 
the proposed rule. Equipment in use at major sources and synthetic 
minor sources was used in the equipment ranking. In accordance with 
section 112(d)(3)(A) of the CAA, equipment at kilns that achieved LAER 
less than 18 months before proposal was not included in the equipment 
ranking. When we ranked the large tunnel kilns, we treated kilns 
equipped with DLA as the best-controlled sources, although DIFF, DLS/
FF, and WS also can achieve the level of performance of a DLA. We 
ranked the kilns by APCD rather than actual unit-specific emissions 
reductions because we do not have emissions test data for all kilns.

[[Page 26700]]

    Section 112(d)(3) of the CAA specifies that we set standards for 
existing sources that are no less stringent than the average emission 
limitation achieved by the best-performing 12 percent of existing 
sources (for which the Administrator has emissions information) where 
there are 30 or more sources in the category or subcategory. Our 
interpretation of average emission limitation is that it is a measure 
of central tendency, such as the arithmetic mean or the median. If the 
median is used when there are at least 30 sources, then the emission 
level achievable by the source and its APCD that is at the bottom of 
the top 6 percent of the best-performing sources (i.e., the 94th 
percentile) represents the MACT floor control level. We based our MACT 
floors for each BSCP subcategory on this interpretation. Nineteen 
percent (22 of 115) of the existing large tunnel kilns located at 
synthetic minor sources or major sources are controlled by a DLA (12), 
DIFF (4), DLS/FF (4), or WS (2). Because more than 6 percent of the 
large tunnel kilns reduce emissions by some technique, emissions 
reductions from these kilns are required under the CAA. We then 
considered which of these controls are proven to be applicable to 
existing tunnel kilns, and we ranked these kilns to determine the 
appropriate MACT emission limits. We consider the 12 DLA to be 
equivalent and believe that this type of control can be applied to any 
existing large tunnel kiln without causing potentially significant 
production problems. We consider the performance of all of the DLA to 
be equivalent because there currently are two types of DLA in the 
industry (supplied by two manufacturers), and we have test data for 
both designs that show HF removal efficiencies that are within 1 
percent of one another. We excluded DIFF and DLS/FF from our ranking of 
controls for existing sources because of the reported problems caused 
by applying DIFF and DLS/FF to existing kilns. We excluded WS from our 
ranking of controls for existing sources because many facilities do not 
have proven wastewater disposal options. Therefore, we only considered 
DLA in our ranking, and accordingly, the 94th percentile source (the 
7th best-controlled source) is a DLA-controlled kiln. Therefore, the 
MACT floors for existing large tunnel kilns are based on the level of 
control achieved by a DLA. We have DLA outlet test data for 7 of the 12 
existing large DLA-controlled tunnel kilns, and therefore, we are 
confident that our test data are within the best-controlled 6 percent 
of sources. Furthermore, the single best-performing source, based on 
our available DLA outlet data, is one of the three sources for which a 
control efficiency is available.
    Section 112(d)(2) of the CAA dictates how we must establish MACT. 
The MACT can either be established at the MACT floor, or can be some 
control level more stringent than the MACT floor or beyond-the-floor. 
Section 112(d)(2) of the CAA states that:

    Emissions standards promulgated under this subsection and 
applicable to new or existing sources of hazardous air pollutants 
shall require the maximum degree of reduction in emissions of the 
hazardous air pollutants subject to this section (including a 
prohibition on such emissions, where achievable) that the 
Administrator, taking into consideration the cost of achieving such 
emission reduction, and any non-air quality health and environmental 
impacts and energy requirements, determines is achievable for new or 
existing sources in the category or subcategory to which such 
emission standard applies * * *.

Although section 112(d)(3) of the CAA does not allow us to consider 
cost when determining MACT floors, we do consider costs when we examine 
beyond-the-floor control options according to section 112(d)(2) of the 
CAA. We acknowledge the commenters' concerns regarding the cost of the 
proposed standards. We determined that beyond-the-floor control 
measures would not be appropriate for existing large BSCP kilns because 
of retrofit costs arising from technical difficulties in retrofitting 
DIFF, DLS/FF, or WS. Thus, the emission limits for existing large 
tunnel kilns in today's final rule are based on the level of control 
achievable with a DLA.
    It is our goal to set emission standards that reflect the 
performance of the best-controlled sources. Once we identified the 
subset of the best-controlled BSCP sources (i.e., DLA-controlled 
kilns), we used the highest emission level associated with these best 
performers to set the emission standard because it was our intent to 
set emission limits that reflect the performance that the best-
controlled sources continually achieve considering variability. All 
sources, including the best-controlled sources, have variability in 
emissions. For example, data (individual test runs) from two tests 
conducted on one DLA-controlled kiln showed HF control efficiencies 
that ranged from 91.6 percent to 96.4 percent. This variability may 
result from APCD performance, and also could result from uncertainty 
associated with the test methods. Commenters have agreed with our 
approach to setting the production-based emission limits at or slightly 
higher than the highest data point, because this approach accounts for 
variability in the performance of individual sources, variability that 
could exist across the industry, and uncertainty in the test methods 
used to measure emissions. Furthermore, use of the highest emission 
level associated with the best performers prevents sources within the 
best-controlled subset from having to remove their existing APCD and 
replace it with a new one that may or may not achieve slightly better 
performance.
    We believe and intend that a well-operated DLA will achieve the 
emission limits set forth in this rulemaking. However, concerns have 
recently been raised that if high concentrations of sulfur exist in the 
kiln exhaust gas stream, the ability of a well-operated DLA to reduce 
the target acid gas HAP emissions (i.e., HF and HCl) may be 
compromised. The data we have does not suggest that these concerns are 
justified. If the EPA receives information showing that they are, EPA 
will take prompt action to resolve the issue through rulemaking and 
ensure that a facility with a well-operated DLA will be in compliance 
with the rule. The EPA will also work with any affected facilities to 
ensure that they are not subject to inappropriate sanctions before we 
are able to complete such a rulemaking.

D. New Source MACT

    Several commenters disagreed that a large (design capacity equal to 
or greater than 9.07 Mg/hr (10 tph) of fired product) tunnel kiln 
equipped with DIFF, DLS/FF or WS was the best-controlled similar source 
for all new tunnel kilns. The commenters expressed concern that the 
DIFF, DLS/FF or WS controls proposed for all new tunnel kilns have not 
been demonstrated on smaller kilns. The commenters argued that 
emissions from small (e.g., less than 9.07 Mg/hr (10 tph)) and large 
tunnel kilns are different because the required airflow and pollutant 
loading is different. The commenters stated that controls such as DIFF, 
DLS/FF, or WS do not decrease in size or cost for kilns below 9.07 Mg/
hr (10 tph) design capacity. The commenters thought that the proposed 
standards for new tunnel kilns would prevent future construction of and 
upgrades to smaller kilns. The commenters recommended that a throughput 
cutoff be provided for new and reconstructed kilns. One commenter 
suggested that EPA create a size-cutoff for new kilns, where the best-
controlled similar source for smaller new kilns is a DLA-controlled 
kiln, and DLS/FF, DIFF, or WS for the larger

[[Page 26701]]

kilns. One commenter noted the potential of existing kilns triggering 
new source requirements during reconstruction. The commenter requested 
that the ability of small businesses to overhaul existing kilns be 
addressed in the final rule.
    These commenters have addressed several related issues including 
the selection of the best-controlled similar source, differences 
between small and large tunnel kilns, the feasibility of the proposed 
MACT-level controls in controlling emissions from smaller tunnel kilns 
or reconstructed tunnel kilns, and the costs of new controls. In 
responding to these comments, we have re-evaluated our analysis of MACT 
for new and reconstructed tunnel kilns. In the original MACT analysis 
developed for the proposed rule, we recognized the inherent differences 
between small and large tunnel kilns and established a 
subcategorization level of 9.07 Mg/hr (10 tph). The proposed 9.07 Mg/hr 
(10 tph) subcategorization level applied to both existing and new 
tunnel kilns. For new and reconstructed sources, we selected the best-
controlled similar source (DIFF, DLS/FF, WS) that would be applied to 
all new sources regardless of size. In re-evaluating this analysis and 
in light of several comments that described the inherent differences 
and issues with the application of DIFF, DLS/FF, and WS control 
technologies to small tunnel kilns or reconstructed tunnel kilns, we 
have revised MACT for new sources. We also have added language in 40 
CFR 63.8390(i) to provide that it is not technologically and 
economically feasible for two types of existing kilns that would 
otherwise meet the criteria for reconstruction under 40 CFR 63.2 to 
meet the relevant standards--i.e., new source MACT--and that such kilns 
do not fall within the definition of reconstruction and are not subject 
to new source MACT requirements. The two types of kilns are existing 
small kilns that are rebuilt such that they become large kilns and 
existing large DLA-controlled tunnel kilns that are rebuilt. Today's 
final emission limits for those kilns and for new and reconstructed 
small tunnel kilns are based on the performance of DLA control 
technology. The final emission limits for new large tunnel kilns are 
based on the performance of DIFF, DLS/FF, and WS control technology. In 
addition, existing large tunnel kilns equipped with DIFF, DLS/FF or WS 
are reconstructed sources subject to new source MACT requirements if 
they meet the criteria for reconstruction in 40 CFR 63.2. Such kilns 
must continue to meet new source MACT limits, which are based on the 
performance of DIFF, DLS/FF, and WS.
    We agree with the commenters that DIFF, DLS/FF, and WS control 
technologies have not been demonstrated on small kilns. However, we 
believe that the 9.07 Mg/hr (10 tph) size represents the threshold 
where emission control using DIFF, DLS/FF, or WS is technically 
feasible and demonstrated. Smaller kilns have smaller airflow rates 
than larger kilns and any fluctuations in airflow rates can have a 
significant impact on the ability of DIFF, DLS/FF, or WS to operate 
correctly. For new and reconstructed small kilns, the DLA control 
technology has been demonstrated to perform adequately despite the 
lower airflow rates; DLA control systems are not as sensitive to 
airflow changes as DIFF, DLS/FF, or WS control systems. In addition, 
existing small kilns that are rebuilt such that they become large kilns 
and existing large DLA-controlled kilns that are rebuilt would 
experience the same types of retrofit problems that we described for 
existing tunnel kilns, and we believe that such tunnel kilns should be 
subject to requirements that can be met with a DLA. The DIFF, DLS/FF, 
and WS control systems have been demonstrated on new large kilns. 
Therefore, MACT for new and reconstructed large tunnel kilns is based 
on DIFF, DLS/FF, and WS control and is unchanged from proposal. 
Finally, the determination of MACT for new sources at the floor does 
not take the cost of control into consideration.
    Our revised standards for new and reconstructed small tunnel kilns, 
existing small kilns that are rebuilt such that they become large 
kilns, and existing large DLA-controlled kilns that are rebuilt are 
based on the use of a DLA, which is considerably less expensive than 
the other MACT controls. The revised standards should minimize the 
commenters' concerns over the costs of reconstructing older kilns.

E. Cost and Economic Impacts

    Numerous comments were received regarding costs of the proposed 
rule. Commenters contended that EPA did not consider the full costs of 
the rule (e.g., costs associated with problems retrofitting existing 
kilns). In general, commenters indicated that the economic impacts to 
brick industry would be severe. Several commenters pointed out that the 
brick industry is losing market share to cheaper building materials 
(e.g., vinyl) that are more detrimental to the environment. The 
commenters stated that the proposed rule would have a negative effect 
on the future of many small businesses and the communities where they 
are located. The commenters expressed concern that the proposed rule 
would limit the opportunity for continued operation or expansion of 
brick plants throughout the U.S. The commenters noted that increased 
production costs would increase brick prices, causing brick to become 
less competitive with other materials and brick imports to rise, 
putting small U.S. companies out of business. Several commenters stated 
that the costs of the rule as proposed would prevent their company from 
ever replacing, performing a major repair on, or upgrading their 
existing kiln. Some commenters stated that the rule as proposed would 
eventually cause their company to go out of business. Some commenters 
added that they live in an economically depressed area and other jobs 
are not readily available.
    One commenter disagreed with the Administrator's certification that 
the proposed rule would not create a significant impact on a 
substantial number of small entities. The commenter submitted an 
Economic Impacts Analysis (EIA). The commenter calculated and presented 
the Sales Test, Cash Flow Test, and Profit Test criteria which the 
commenter believes shows a greater number of small businesses at risk 
than does EPA's EIA. In addition, the commenter provided several 
specific comments on EPA's EIA. The commenter argued that the rule as 
proposed is a significant rulemaking per Executive Order (E.O.) 12866. 
A few commenters provided specific comments on the monitoring, 
reporting, and recordkeeping costs in the Office of Management and 
Budget (OMB) 83-I form and supporting statement.
    Commenters also questioned the environmental benefits of the BSCP 
rule as proposed. One commenter questioned why the BSCP rule is 
necessary if brick manufacturing emissions are not causing public 
health problems or adverse environmental effects. Another commenter 
argued that there is no epidemiological evidence that anyone in North 
America has been harmed by brick plant HF emissions and that cancer 
incidence in brick plant workers is not higher than for the general 
population.
    As previously mentioned in this preamble, section 112(b) of the CAA 
contains a list of HAP identified by Congress and authorizes EPA to add 
to that list pollutants that present or may present a threat of adverse 
effects to human health or the environment. Section 112(c) of the CAA 
requires us to list all categories and subcategories of major and area 
sources of HAP and to

[[Page 26702]]

establish NESHAP for the listed source categories and subcategories 
under section 112(d) of the CAA. Because BSCP manufacturing is a listed 
source category containing major sources of HAP, we are required by the 
CAA to establish NESHAP for BSCP manufacturing.
    As stated previously, MACT can either be established at the MACT 
floor, or can be some control level more stringent than the MACT floor 
or beyond the floor. Section 112(d)(3) of the CAA does not allow us to 
consider cost when determining MACT floors. We are only allowed to 
consider costs when we examine beyond-the-floor control options 
according to section 112(d)(2) of the CAA. We acknowledge the 
commenters' concerns regarding the cost of the proposed rule. At 
proposal, we determined that beyond-the-floor control measures would 
not be appropriate for the BSCP industry, in part because of costs.
    Following proposal, we reevaluated the MACT floors for existing 
tunnel kilns and have revised the standards to incorporate use of DLA 
on existing large tunnel kilns. We also revised the MACT standards for 
new and reconstructed small tunnel kilns, existing small kilns that are 
rebuilt such that they become large kilns, and existing large DLA-
controlled tunnel kilns that are rebuilt such that the standards are 
based on the level of performance that can be achieved by a DLA. (MACT 
requirements for existing small tunnel kilns and new and reconstructed 
large tunnel kilns remain unchanged.) We continue to agree that beyond-
the-floor control measures are not warranted for the BSCP industry. The 
revised MACT standards for new and reconstructed small tunnel kilns, 
existing small kilns that are rebuilt such that they become large 
kilns, and existing large DLA-controlled kilns that are rebuilt are the 
same as the revised standards for existing large tunnel kilns. These 
revised standards are less costly and should reduce concerns regarding 
cost of retrofitting or rebuilding existing kilns and starting up new 
small kilns. Environmental benefits of today's final BSCP rule are 
discussed later in this preamble.
    EPA reviewed the economic impact analysis report submitted by the 
commenter. We have revised our EIA to identify additional small 
businesses affected by the rule. We have also incorporated the lower 
revised cost estimates into the EIA. Impacts on small businesses are 
considerably lower in the revised analysis and prices are predicted to 
rise by less than one percent on average. The results of our revised 
EIA, as well as a discussion of the impact of today's final rule on 
small businesses, are presented later in this preamble.
    Comments on the costs of monitoring, reporting, and recordkeeping 
were incorporated into the revised OMB 83-I form and supporting 
statement as appropriate. A discussion of the OMB 83-I form and 
supporting statement prepared in compliance with the Paperwork 
Reduction Act is presented later in this preamble.

F. Test Data and Emission Limits

1. HF and HCl Emission Limits
    Commenters stated that the test data EPA used to set the HF and HCl 
limits are questionable. An independent consultant, hired by the BSCP 
industry, reviewed the data and determined that six of the seven test 
runs used the wrong filter media. A glass filter media was used instead 
of a Teflon filter. The commenter suggested that, as a result, the data 
could be biased. One commenter also charged that EPA removed high test 
runs without any technical basis even though all of these runs met the 
same quality control (QC) criteria as other runs. Finally, one 
commenter stated that EPA's use of both HF and total fluorides (TF) 
data to develop the average uncontrolled HF emission factor (which was 
used in developing the HF emission limit) was unsupported, and the 
commenter believes that EPA should use only the HF test data because HF 
is the regulated pollutant.
    We have reviewed the emission tests mentioned by the commenter and 
agree that there are some problems with most of the available test 
data, and we have accounted for any potential bias by revising the 
emission limits. In consultation with EPA's Emission Measurement Center 
(EMC), we used a conservative approach to determine the possible impact 
of the bias on the percent reduction emission limits. The analysis 
showed that our available percent reduction data could be as much as 
about 5 percent high, and we, therefore, decreased the corresponding HF 
and HCl percent reduction requirements by 5 percent and adjusted the 
corresponding production-based emission limits accordingly. In response 
to the commenter's assertion that we dropped two test runs without a 
technical reason, we examined the test runs in question and 
incorporated one of the two runs back into the data set used for 
developing the standards. Finally, in response to the appropriateness 
of using TF data in calculating the average HF emission factor, while 
the average of the TF and HF data sets suggest that TF and HF 
measurements are similar, we recognize the inconsistencies between the 
few available side-by-side HF and TF tests and we, therefore, decided 
to remove the TF data from the HF emission factor calculation. Based on 
the three issues discussed above, we revised the emission limits for 
kilns where MACT is based on use of DIFF, DLS/FF, or WS (i.e., for new 
large kilns). Today's final rule requires new large kilns to limit HF 
emissions to 0.029 kilograms per megagram (kg/Mg) (0.057 pounds per ton 
(lb/ton)) of fired product or reduce HF emissions by 90 percent; and 
limit HCl emissions to 0.028 kg/Mg (0.056 lb/ton) or reduce HCl 
emissions by 85 percent.
    The revised HF and HCl emission limits for existing large tunnel 
kilns, new and reconstructed small tunnel kilns, existing small kilns 
that are rebuilt such that they become large kilns, and existing large 
DLA-controlled tunnel kilns that are rebuilt are based on the use of a 
DLA for HAP reduction. Two HF emission tests (both conducted on the 
same source) and two total fluorides emission test are available for 
DLA-controlled kilns, and the tests showed HF or TF control 
efficiencies of 92.3 percent (HF), 96.4 percent (HF), 93.3 percent 
(TF), and 93.5 percent (TF). Similar to the DIFF and DLS/FF tests, we 
identified problems with the two HF emission tests that could have 
biased the control efficiencies high. To account for this uncertain 
bias, and considering typical vendor guarantees for DLA systems 
(vendors will guarantee 90 percent HF reduction unless a lesser 
percentage meets the customer's need, in which case the vendors 
typically provide lower guarantees), we selected a percent reduction 
emission limit of 90 percent for HF. We applied this 90 percent 
reduction to the revised average HF emission factor of 0.29 kg/Mg (0.57 
lb/ton) to calculate a production-based HF emission limit of 0.029 kg/
Mg (0.057 lb/ton). Control efficiency data for HCl are available from 
two tests on a single DLA-controlled kiln. The tests averaged 30.7 
percent control, and we selected a percent reduction HCl emission limit 
of 30 percent. We applied this 30 percent reduction to the average HCl 
emission factor of 0.19 kg/Mg (0.37 lb/ton) to calculate a production-
based HCl emission limit of 0.13 kg/Mg (0.26 lb/ton).
    Percent of HAP metals in PM. Several commenters noted that HAP 
metals and PM data from four facilities (0.16 percent, 0.99 percent, 
2.8 percent, and 4.5 percent) were used to arrive at 1.9 percent of the 
PM is PM HAP. The

[[Page 26703]]

commenters stated that EPA included an invalid, high data point for 
manganese in developing the percentage of PM that is PM HAP. We have 
examined the test run mentioned by the commenters and agree that the 
run should be voided. Our revised analyses now indicate that the 
overall percentage of PM that is HAP metals is 0.72 percent.
    PM limit. Other commenters argued that a PM limit for brick kilns 
is unnecessary. One commenter noted that metals occur naturally in 
clays or shales used to make bricks and that PM emissions from BSCP 
plants are clay dust. The commenter argued that metals are locked into 
the structure of the clay dust and are not bio-available to affect 
humans through respiratory adsorption, ingestion, or dermal contact. 
Some commenters noted that there is limited information on the amount 
of HAP metals in the PM emitted. Commenters pointed out that EPA is not 
setting a PM limit for clay refractory kilns. Some commenters disagreed 
that PM is an adequate surrogate for HAP metals emissions. Commenters 
also requested that a percent reduction alternative be allowed for the 
PM standard, similar to the percent reduction limits for HF and HCl.
    We agree that PM emitted from BSCP facilities is largely clay dust, 
and that metals are naturally occurring in clays and shales used to 
make bricks. Many BSCP facilities apply surface coatings or body 
additives containing HAP metals to their products, and these coatings 
are another potential source of HAP metals emissions. These types of 
additives and coatings are not used in the manufacture of clay 
refractories.
    We have four emission tests for HAP metals from tunnel kilns and 
all of these tests measured some level of HAP metals emissions 
including emissions of antimony, arsenic, beryllium, cadmium, chromium, 
cobalt, mercury, manganese, nickel, lead, and selenium. Based on these 
data, we believe that all kilns emit some level of HAP metals and, 
therefore, we are regulating HAP metals emissions. Test data for HAP 
metals are not available for clay refractories kilns.
    We are unaware of any information to support the idea that the HAP 
metals are locked into the structure of the clay and are not bio-
available to affect humans. In the absence of such information and in 
the interest of protecting public health, we assume conservatively that 
the HAP metals are bio-available and could affect human health. This 
assumption is consistent with the conservative approach embodied in the 
CAA section 112(b)(2) directive that EPA add pollutants to the 
statutory list of HAP that ``may'' present adverse risks to human 
health and the environment through various exposure routes.
    We used PM as a surrogate for HAP metals so that individual 
emission limits would not be based on the limited and variable data. We 
examined the available HAP metals test data and calculated that about 
95 percent of the HAP metals emissions are in particulate form. 
Furthermore, the types of control technologies used on BSCP kilns 
remove PM and would indiscriminately remove particulate HAP metals. The 
United States Court of Appeals for the District of Columbia Circuit 
stated in a December 15, 2000 decision (in response to the National 
Lime Association (NLA) challenge of the use of PM as a surrogate for 
HAP metals), ``if HAP metals are invariably present in cement kiln PM, 
then even if the ratio of metals to PM is small and variable, or simply 
unknown, PM is a reasonable surrogate for the metals--assuming * * * 
that PM control technology indiscriminately captures HAP metals along 
with other particulates.'' Our use of PM as a surrogate for HAP metals 
in the final BSCP rule is consistent with this decision.
    We typically do not include percent reduction as an alternative for 
PM because a percent reduction standard rewards those facilities that 
have high inlet PM loadings. We believe that this is different from the 
percent reduction standards for HF and HCl because facilities do not 
typically have options for reducing the uncontrolled levels of HF or 
HCl. Therefore, we are not providing an alternative percent reduction 
standard for PM.
    The revised PM emission limit for existing large tunnel kilns, new 
and reconstructed small tunnel kilns, existing small kilns that are 
rebuilt such that they become large kilns, and existing large DLA-
controlled tunnel kilns that are rebuilt is based on the use of a DLA. 
Data from four tests conducted at the outlets of DLA were available for 
establishing a production-based emission limit, and we selected the 
highest PM data point as the emission limit in order to account for 
variability. Today's final rule contains a PM emission limit of 0.21 
kg/Mg (0.42 lb/ton) of fired product for existing large tunnel kilns, 
new and reconstructed small tunnel kilns, existing small kilns that are 
rebuilt such that they become large kilns, and existing large DLA-
controlled tunnel kilns that are rebuilt. The PM emission limit for new 
and reconstructed large tunnel kilns is unchanged from proposal (0.060 
kg/Mg (0.12 lb/ton) of fired product).

G. Monitoring Requirements

    Numerous comments were received on the proposed monitoring 
requirements. Some commenters felt that the monitoring, reporting, and 
recordkeeping requirements were unreasonable. Commenters noted that the 
monitoring requirements would require additional and higher skilled 
personnel.
    Under section 114(a)(3) of the CAA, owners or operators of major 
sources are required to conduct enhanced monitoring of affected sources 
to ensure compliance with applicable emission standards. In response to 
this mandate, we have incorporated continuous compliance requirements 
into all part 63 standards, generally in the form of continuous 
emissions monitoring or continuous parameter monitoring. We believe 
that continuous monitoring is needed to ensure that emission controls 
are operated properly. However, 40 CFR 63.8(f) allows owners and 
operators of affected sources to request approval for alternative 
monitoring procedures to demonstrate compliance with emission 
limitations.
    Although we have eliminated some of the proposed monitoring 
requirements (such as fabric filter inlet temperature monitoring) from 
today's final rule, we have retained most of the proposed monitoring 
requirements. We believe that those monitoring requirements are the 
minimum needed to ensure continuous compliance with the emission 
limits.
1. Operation, Maintenance, and Monitoring (OM&M) Plan
    Some commenters felt that development of an OM&M plan was overly 
burdensome. One commenter thought the requirement to include OM&M 
procedures for kiln operation was unjustified. Another commenter noted 
possible contradictions of OM&M plan requirements and Table 7 of the 
proposed BSCP rule (the table showing applicability of the General 
Provisions to part 63).
    After reviewing these comments, we decided that OM&M plans do not 
have to include procedures for monitoring the operation and maintenance 
of tunnel kilns, and we have written the final rule accordingly. 
However, we continue to believe that site-specific OM&M plans are 
necessary to ensure continued proper operation of any control device 
that is used to comply with the final rule.
    Regarding the apparent contradictions between 40 CFR 63.8425(b)(8) 
through (10) and Table 7 of the proposed rule, we did not cite the 
General Provisions

[[Page 26704]]

to part A in the proposed 40 CFR 63.8425 (b)(8) through (10), but 
specified that OM&M plans must include operation and maintenance, 
quality assurance, and reporting and recordkeeping procedures that are 
consistent with the General Provisions. Therefore, we believe there is 
no contradiction between 40 CFR 63.8425 (b)(8) through (10) and Table 7 
of the proposed rule. However, we did clarify in Table 7 of the final 
rule that 40 CFR 63.8(c)(4) does not apply to subpart JJJJJ because 40 
CFR 63.8425 and 63.8465 specify the requirements for continuous 
monitoring systems (CMS).
    Some commenters requested clarification on whether OM&M plans (and 
startup, shutdown, and malfunction plans (SSMP)) are required for kilns 
that would not be subject to control requirements (e.g., existing small 
tunnel kilns). Another commenter questioned if an OM&M plan would be 
required if compliance is achieved without a control device. The BSCP 
NESHAP applies only to affected sources. Under today's final rule, an 
existing small tunnel kiln is not an affected source. Therefore, the 
requirements for OM&M plans, SSMP, and other monitoring, notification, 
reporting, and recordkeeping requirements do not apply to those kilns. 
Owners or operators will be required to prepare an OM&M plan and SSMP 
for any kiln that is an affected source even if the kiln can meet the 
emission limits without the use of a control device.
2. Bag Leak Detectors
    Commenters indicated that bag leak detectors are unnecessary, 
overly protective, and maintenance intensive. The commenters noted that 
bag failure is noticeable because PM emissions would be visible at the 
stack. Several commenters requested that opacity or visible emissions 
(VE) determinations be allowed as opposed to bag leak detectors.
    We agree with the commenters that periodic VE checks should provide 
a reasonable alternative to bag leak detectors, and we have written the 
final rule accordingly. In today's final rule, owners and operators of 
affected kilns that are controlled with a DLS/FF or DIFF can choose 
between installing a bag leak detection system or performing daily VE 
checks. Today's final rule also includes a provision for decreasing the 
frequency of VE checks provided no VE are observed.
3. Water Injection Rate Monitoring on DLS/FF
    Three commenters stated that DLS/FF water injection rate monitoring 
has nothing to do with HF or HCl removal (but is important for sulfur 
dioxide (SO2) removal) and recommended that the provision 
for monitoring DLS/FF water injection rate be eliminated.
    After reviewing the available information, we decided to eliminate 
the requirement for water injection rate monitoring on affected DLS/FF-
controlled kilns. Water injection is used to enhance the removal of 
SO2 by a DLS/FF, but has little effect on removal of HF and 
HCl.
4. Fabric Filter Inlet Temperature
    Several commenters recommended that the requirement to monitor 
fabric filter inlet temperature be eliminated from the rule as 
proposed. The commenters explained that it would be impractical to hold 
the fabric filter inlet temperature to within 25 degrees below the 
average established during the performance test. The fabric filter 
inlet temperature varies frequently, much more than 25 degrees, because 
of many process factors. Other commenters noted that fabric filter 
inlet temperature has little relevancy to acid gas control. One 
commenter stated that control systems using hydrated lime are generally 
known to have increased HCl and HF removal when temperatures increase.
    As a result of these comments, we have eliminated the requirement 
for monitoring fabric filter inlet temperatures on affected kilns that 
are controlled with a DLS/FF or DIFF. We believe that the other 
monitoring requirements (e.g., lime feed rate monitoring and periodic 
VE checks) that we have incorporated into the final rule are adequate 
for ensuring continuous compliance with the emission limits.
5. DLA Parameter Monitoring
    Many commenters suggested potential parametric monitoring 
requirements for DLA that could be used to demonstrate continuous 
compliance. Various commenters suggested documenting use, on a 
continuous basis, of the same limestone that was used during the 
performance test demonstrating compliance. Other suggestions included 
monitoring pressure drop (demonstrating airflow); limestone flow; and 
inlet and/or exhaust gas temperature.
    We have incorporated parameter monitoring requirements for DLA into 
the final rule based on information provided by commenters and a recent 
site visit to a facility operating a DLA. Today's final rule will 
require owners and operators of affected kilns with DLA to continuously 
monitor the pressure drop across the DLA; perform a daily visual check 
of the limestone hopper and storage bin (located at the top of the 
DLA), and record the limestone feeder setting daily; and perform 
periodic VE observations. In addition, owners and operators will be 
required to document the source of the limestone used during the most 
recent performance test and maintain records that demonstrate that the 
source of limestone has not changed.
6. Continuous Emission Monitoring Systems
    In the preamble to the proposed rule, we requested comment on 
requiring the application of PM continuous emission monitoring systems 
(CEMS) as a method to assure continuous compliance with the proposed PM 
emission limits for BSCP tunnel kilns. While we believe there is 
evidence that PM CEMS should work on BSCP tunnel kilns, we received no 
comments in support of requiring PM CEMS. Commenters opposed use of 
CEMS when less expensive, but effective, parametric monitoring 
alternatives are available. Therefore, today's final rule does not 
require use of PM CEMS or any other type of CEMS. We believe that the 
parameter monitoring requirements specified in the final rule are 
adequate for ensuring continuous compliance.
7. Establishing/Re-Establishing Production Rate
    Several commenters requested that the process weight threshold be 
based on average annual throughput instead of hourly or monthly 
throughput. One commenter pointed out that the nature of brick 
production does not allow for spikes in emissions. Several commenters 
stated that the averaging period used to determine the MACT floor 
applicability to existing tunnel kilns must have the same production 
averaging basis as the data used in setting the subcategorization 
level. The commenters stated that it is not reasonable to base the 
standard on a 12-month averaging period and then enforce the floor on 
an instantaneous or 30-day rolling averaging period.
    One commenter requested clarification as to whether EPA would 
require a retest if the maximum production level of a kiln would be 
higher than the level observed during the performance test. The 
commenter added that several States recognize that capacity and maximum 
production are difficult figures to calculate for a brick kiln because 
they are highly dependent

[[Page 26705]]

on the specific characteristics of a product (size, percent void).
    We agree with the commenters that a kiln's process weight threshold 
(e.g., design capacity level) should be based on average annual tonnage 
rather than on the proposed 30-day rolling average. We have revised the 
final BSCP rule accordingly to require the ton per hour production 
capacity of a kiln to be calculated based on the maximum amount of BSCP 
(in tons) that can be produced in a 12-month period divided by 8,760 
hours per year.
    Regarding the question of whether we will require a retest if the 
maximum production level of a kiln is higher than the level observed 
during the performance test, a retest will be required because an 
increase in production is likely to increase emissions, and the 
operating limits that are based on the performance test would no longer 
demonstrate continuous compliance with the emission limits.
8. Test Methods
    One commenter requested that we allow any of the applicable EPA 
Method 5 variations to demonstrate compliance with the PM standard. The 
commenter pointed out that a facility with high SO2 could 
reduce the potential for SO2 to be counted as PM by using 
EPA Method 5B. We are not including EPA Method 5B as a test method 
because our emission limit is based on EPA Method 5 and includes tests 
on sources with high SO2 emissions. Individual facilities 
will have the option of requesting an alternative test method.
    One commenter on the proposed clay ceramics rule requested that the 
final rule provide facilities with the option to use either EPA Method 
26A or EPA Method 320 for all required stack testing for HF and HCl. 
This comment applies for both BSCP and clay ceramics. Therefore, we 
have modified today's final BSCP rule to include EPA Method 320 as an 
alternative to EPA Method 26A.

H. Startup, Shutdown, and Malfunction

1. APCD Bypass
    Several commenters stated that the BSCP rule, as proposed, would 
not allow the kiln control device to be bypassed at any time. Various 
commenters stated that the proposed MACT controls (DIFF, DLS/FF, or WS) 
must maintain a given flow to perform efficiently. Thus, the APCD would 
dictate how the kiln is operated. During initial kiln startup or 
subsequent kiln startups or shutdowns, airflow temperatures and volumes 
would be below APCD design volumes. The heat from the furnace zone 
could damage the kiln walls and cars if not vented. Therefore, the 
ability to bypass during startups, routine maintenance, and emergency 
shutdowns of the APCD is needed.
    Several commenters noted that brick kilns are constant flow devices 
that cannot just be turned off without detrimental impact to large 
volumes of product (e.g., character, color, and quality of brick) and 
the kiln itself. The commenters stated that days to weeks may be needed 
to properly shut down a brick kiln. One commenter noted that kilns 
operate continuously 2 to 3 years before being shut down for routine 
maintenance.
    Commenters stated that short periods of bypass are necessary to 
conduct routine preventive maintenance inspections of APCD. Commenters 
pointed out that the control devices currently employed have and use 
bypass capability for routine maintenance and emergency repairs.
    We generally agree with the commenters that some provision is 
needed to allow the control device on tunnel kilns to be bypassed for 
routine maintenance of the control device, and we have revised the rule 
accordingly. Under 40 CFR 63.8420(e) of today's final rule, owners and 
operators of an affected tunnel kiln can bypass the kiln control device 
for a cumulative period of up to 4 percent of the annual operating 
hours for the kiln. Based on the data and other information submitted 
by commenters on the proposed rule, we believe that the amount of time 
equating to 4 percent of annual kiln operating hours is adequate for 
completing routine maintenance on the types of controls that are likely 
to be used to comply with the BSCP NESHAP.
    To comply with this bypass provision, owners or operators must 
submit a request to us for a routine control device maintenance 
exemption. The request must justify the need for the routine 
maintenance on the control device and the time required to complete the 
maintenance activities. The request also must describe the maintenance 
activities and the frequency of the maintenance activities, explain why 
the maintenance cannot be accomplished during kiln shutdowns, and 
describe how emissions will be minimized during the period when the 
kiln is operating and the control device is offline. Upon approval, the 
request for exemption must be incorporated by reference in, and 
attached to, the affected source's title V permit. During any period 
when the kiln is operating and the kiln control device is offline, the 
owner or operator must minimize HAP emissions. The duration of such 
periods also must be minimized.
    We also note that the bypass provision included in today's final 
rule does not apply to startups, shutdowns, or malfunctions. 40 CFR 
63.6(f)(1) explicitly states that nonopacity emission standards, such 
as the proposed emission limits for HF, HCl, and PM, ``* * * apply at 
all times except during periods of startup, shutdown, and malfunction * 
* *'' Startups, shutdowns, and malfunctions must be addressed in a 
facility's SSMP.
2. Initial Startup
    Commenters stated that it is impractical to meet emission standards 
during initial startup of a tunnel kiln. The commenters indicated that 
it can take from weeks to a year to bring new BSCP kilns online. In 
addition, APCD such as DIFF, DLS/FF, or WS cannot be brought online 
until adequate temperature and airflow ranges are met. The commenters 
indicated that roughly 75 percent of design gas flow rate or kiln 
production rate must be obtained before a DIFF or DLS/FF could begin to 
operate properly. Another commenter stated that the proposed initial 
testing deadline (180 days following the compliance date) would not 
provide enough time for a new kiln to come up-to-speed.
    We recognize that an extended period of time may be needed for the 
initial startup of a new kiln and have added a definition of initial 
startup to the BSCP final rule to address the concerns expressed by the 
commenters. The definition differentiates between DLA-controlled kilns 
and DIFF-, DLS/FF-, or WS-controlled kilns, because DLA are not 
sensitive to airflow and only require that the kiln gases are hot 
enough to avoid condensation in the DLA. Avoiding condensation is 
necessary because water and calcium carbonate (limestone) combine to 
make cement, and any introduction of water in the DLA reaction chamber 
could cause the limestone to be cemented together. In the final rule, 
we provided the following definition: ``Initial startup'' means: (1) 
For a new or reconstructed tunnel kiln controlled with a DLA, and for a 
tunnel kiln that would be considered reconstructed but for 40 CFR 
63.8390(i)(1) or 40 CFR 63.8390(i)(2), the time at which the 
temperature in the kiln first reaches 260 [deg]C (500 [deg]F) and the 
kiln contains product; or (2) for a new or reconstructed tunnel kiln 
controlled with a DIFF, DLS/FF, or WS, the time at which the kiln first 
reaches a level of production that is equal to 75 percent of the kiln 
design capacity or 12 months

[[Page 26706]]

after the affected source begins firing BSCP, whichever is earlier. 
Although some commenters suggested that initial startup for DIFF-, DLS/
FF-, and WS-controlled kilns be defined in terms of airflow, we defined 
initial startup in terms of production rate for DIFF-, DLS/FF-, and WS-
controlled kilns because the final rule requires owners and operators 
of affected sources to monitor production rate, whereas flowrate 
monitoring is not required under today's final rule. We included the 
stipulation for DIFF-, DLS/FF-, and WS-controlled kilns that initial 
startup occurs no later than 12 months after the new kiln begins firing 
BSCP to prevent facilities from operating an affected new or 
reconstructed kiln at just less than 75 percent of the kiln design 
capacity long term to circumvent the final rule. A similar stipulation 
is not necessary for DLA-controlled kilns because the kiln temperature 
requirement is such that the kiln cannot produce BSCP until well after 
the temperature is reached.
    By defining initial startup in today's final rule, we also have 
clarified the compliance date for new and reconstructed sources, which 
is specified in terms of the initial startup. Thus, new and 
reconstructed DIFF-, DLS/FF-, and WS-controlled tunnel kilns beginning 
operation after the promulgation date will be allowed to reach 75 
percent of the kiln design capacity before initial startup is triggered 
and the APCD must come online. New and reconstructed DLA-controlled 
tunnel kilns, and tunnel kilns that would be considered reconstructed 
but for 40 CFR 63.8390(i)(1) or 40 CFR 63.8390(i)(2), beginning 
operation after the promulgation date will trigger initial startup when 
the temperature in the kiln first reaches 260[deg]C (500[deg]F) and the 
kiln contains product. Performance testing is required 180 days 
following the compliance date (i.e., 180 days following initial 
startup). Facilities wishing to conduct performance testing to 
determine the level of air pollution control necessary may conduct such 
testing prior to achieving initial startup.
3. Startup
    Two commenters expressed concern with how startup is defined with 
respect to the proposed rule. The commenters stated that, under the 
proposed rule, a kiln could be considered to be operating if only one 
burner was operating. However, a kiln could have as many as 100 burners 
or more. To clarify what constitutes kiln startup we added to today's 
final rule a definition of ``startup'' that incorporates ``starting the 
production process.''
4. Deviations
    One commenter felt that the requirement of reporting emissions as 
deviations during startup, shutdown, or malfunction (SSM) is 
inappropriate because facilities are not required to be in compliance 
with the emission limitations during SSM. Another commenter requested 
that EPA make it clear the deviations are not necessarily an indication 
of noncompliance or excess emissions.
    The term deviation applies to events during which an affected 
source fails to meet an emission limitation or comply with another 
requirement of the final rule. Deviations are not synonymous with 
violations; depending on the circumstances, a deviation may or may not 
be a violation of an applicable requirement. We agree with the 
commenter that an affected source need not be in compliance with 
emission limits during periods of SSM. Although we consider non-
compliance with emission limits during startup, shutdown, and 
malfunction to be deviations from the emission limits, we do not 
consider these deviations to be violations of the emission limits. 40 
CFR 63.7(e)(1) specifies that, ``Operations during periods of startup, 
shutdown, and malfunction shall not constitute representative 
conditions for the purpose of a performance test, nor shall emissions 
in excess of the level of the relevant standard during periods of 
startup, shutdown, and malfunction be considered a violation of the 
relevant standard unless otherwise specified in the relevant standard 
or a determination of noncompliance is made under 40 CFR 63.6(e).'' As 
indicated in Table 7 of the final rule, this language of the general 
provisions to part 63 does apply to subpart JJJJJ. The definition of 
deviation included in today's final rule is consistent with how 
deviation is defined in other NESHAP, and has not been changed since 
proposal.

I. Risk-Based Approaches

    The preamble to the proposed BSCP rule requested comment on whether 
there might be further ways to structure the BSCP rule to focus on the 
facilities which pose significant risks and avoid the imposition of 
high costs on facilities that pose little risk to public health and the 
environment. Specifically, we requested comment on the technical and 
legal viability of two risk-based approaches: (1) An applicability 
cutoff for threshold pollutants under the authority of CAA section 
112(d)(4); and (2) subcategorization and delisting under the authority 
of CAA sections 112(c)(1) and 112(c)(9).\3\ We indicated that we would 
evaluate all comments before determining whether either approach would 
be included in the final BSCP rule. Numerous commenters submitted 
detailed comments on these risk-based approaches. These comments are 
summarized in the BSCP Response-to-Comments document (see SUPPLEMENTARY 
INFORMATION section).
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    \3\ See 68 FR 1276 (January 9, 2003) (Plywood and Composite Wood 
Products Proposed NESHAP) and docket number A-98-44, Item No. II-D-
525 (White papers submitted to EPA outlining the risk-based 
approaches).
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    Based on our consideration of the comments received and other 
factors, we have decided not to include the risk-based approaches in 
today's final BSCP rule. The risk-based approaches described in the 
proposed BSCP rule and addressed in the comments we received raise a 
number of complex issues. In addition, we are under time pressure to 
complete the BSCP rule, because the statutory deadline for promulgation 
has passed and a deadline suit has been filed against EPA. (See Sierra 
Club v. Whitman, Civil Action No. 1:01CV01537 (D.D.C.).) Given the 
range of issues raised by the risk-based approaches and the need to 
promulgate a final rule expeditiously, we believe that it is 
appropriate not to include any risk-based approaches in today's final 
BSCP rule. Nonetheless, we expect to continue to consider risk-based 
approaches in connection with other proposed NESHAP where we have 
described and solicited comment on such appr