[Federal Register Volume 63, Number 56 (Tuesday, March 24, 1998)]
[Proposed Rules]
[Pages 14182-14248]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 98-6678]
[[Page 14181]]
_______________________________________________________________________
Part II
Environmental Protection Agency
_______________________________________________________________________
40 CFR Part 63
National Emission Standards for Hazardous Air Pollutants; Proposed
Standards for Hazardous Air Pollutants Emissions for the Portland
Cement Manufacturing Industry; Proposed Rule
Federal Register / Vol. 63, No. 56 / Tuesday, March 24, 1998 /
Proposed Rules
[[Page 14182]]
ENVIRONMENTAL PROTECTION AGENCY
40 CFR Part 63
[IL-64-2-5807; FRL-5978-2]
RIN 2060-AE78
National Emission Standards for Hazardous Air Pollutants;
Proposed Standards for Hazardous Air Pollutants Emissions for the
Portland Cement Manufacturing Industry
AGENCY: Environmental Protection Agency (EPA).
ACTION: Proposed rule and notice of public hearing.
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SUMMARY: This action proposes national emission standards for hazardous
air pollutants (NESHAP) for new and existing sources in portland cement
manufacturing plants. Exposure to the hazardous air pollutants (HAPs)
in these emissions may be associated with a wide variety of effects,
including carcinogenic, respiratory, nervous system, dermal,
developmental, and/or reproductive health effects. Implementation of
the proposed requirements would reduce emissions of several HAPs.
The standards are proposed under the authority of section 112(d) of
the Clean Air Act as amended (the Act) and are based on the
Administrator's determination that portland cement manufacturing plants
may reasonably be anticipated to emit several of the HAPs listed in
section 112(b) of the Act from the various process operations found
within the industry. The proposed NESHAP would provide protection to
the public by requiring all portland cement plants which are major
sources to meet emission standards reflecting the application of the
maximum achievable control technology (MACT).
DATES: Comments. The EPA will accept comments on the proposed rule
until May 26, 1998.
Public Hearing. If anyone contacts the Agency requesting to speak
at a public hearing, the hearing will be held at the Agency's Office of
Administration Auditorium, Research Triangle Park, North Carolina on
April 23, 1998 beginning at 10:00 a.m. Persons wishing to present oral
testimony must contact the Agency by April 14, 1998.
ADDRESSES: Comments. Comments should be submitted (in duplicate) to:
Air and Radiation Docket and Information Center (6102), Attention:
Docket No. A-92-53, U.S. Environmental Protection Agency, 401 M Street
SW., Washington, DC 20460. The Agency requests that a separate copy
also be sent to the contact person listed below (Mr. Joseph Wood).
Comments and data may also be submitted electronically by following the
instructions provided in the SUPPLEMENTARY INFORMATION section. No
confidential business information (CBI) should be submitted through
electronic mail.
Public Hearing. Persons wishing to present oral testimony or to
inquire as to whether or not a hearing is to be held should notify Ms.
Cathy Coats, Minerals and Inorganic Chemicals Group (MD-13), U.S.
Environmental Protection Agency, Research Triangle Park, NC 27711,
telephone number (919) 541-5422. Additional information regarding the
public hearing is given in the SUPPLEMENTARY INFORMATION section.
Docket. The official record for this rulemaking, as well as the
public version, has been established under Docket No. A-92-53
(including comments and data submitted electronically as described
below). A public version of this record, including printed, paper
versions of electronic comments and data, which does not include any
information claimed as CBI, is available for inspection from 8 a.m. to
4 p.m., Monday through Friday, excluding legal holidays. The official
rulemaking docket is located at the address in the ADDRESSES section
above. Alternatively, a docket index, as well as individual items
contained within the docket, may be obtained by calling (202) 260-7548.
A reasonable fee may be charged for copying.
FOR FURTHER INFORMATION CONTACT: For information about this proposed
rule, contact Mr. Joseph Wood, P.E., Minerals and Inorganic Chemicals
Group, Emission Standards Division (MD-13), U.S. Environmental
Protection Agency, Research Triangle Park, NC 27711, telephone number
(919) 541-5446; electronic mail address wood.joe@epamail.epa.gov. For
information about the proposed test methods contact Ms. Rima
Dishakjian, Emission Measurement Center, Emissions, Monitoring and
Analysis Division (MD-19), U.S. Environmental Protection Agency,
Research Triangle Park, NC 27711, telephone number (919) 541-0443.
SUPPLEMENTARY INFORMATION: Electronic filing. Electronic comments can
be sent directly to the EPA at a-and-r-docket@epamail.epa.gov.
Electronic comments and data must be submitted as an ASCII file
avoiding the use of special characters and any form of encryption.
Comments and data will also be accepted on disks in Wordperfect 5.1 or
6.1 file format or ASCII file format. All comments and data in
electronic form must be identified by the docket number A-92-53.
Electronic comments may be filed online at many Federal Depository
Libraries.
Implementation of the proposed requirements would achieve an
emission reduction from existing and projected new sources estimated at
82 megagrams per year (Mg/yr) (90 tons per year [tpy]) of HAPs and
4,900 Mg/yr (5,400 tpy) of other pollutants (volatile organic compounds
[VOC] and particulate matter [PM]). The EPA is also proposing to
require portland cement plants that are area sources to meet emission
standards for dioxins and furans reflecting the application of MACT.
The EPA is also proposing Methods 320, 321, and 322 with the
standards for addition to 40 CFR part 63, appendix A. These methods may
be used to assist in determining the applicability of the proposed
emission limitations.
Public Hearing. If a public hearing is requested and held, EPA will
ask clarifying questions during the oral presentation but will not
respond to the presentations or comments. Written statements and
supporting information will be considered with equivalent weight as any
oral statement and supporting information subsequently presented at a
public hearing, if held.
Confidential Business Information. Commenters wishing to submit
proprietary information for consideration should clearly distinguish
such information from other comments and clearly label it
``Confidential Business Information.'' Submissions containing such
proprietary information should be sent directly to the following
address, and not to the public docket, to ensure that proprietary
information is not inadvertently placed in the docket: Attention: Mr.
Joseph Wood, c/o Ms. Melva Toomer, U.S. EPA Confidential Business
Information Manager, OAQPS (MD-13); Research Triangle Park, NC 27711.
Information covered by such claim of confidentiality will be disclosed
by the EPA only to the extent allowed and by the procedures set forth
in 40 CFR part 2. If no claim of confidentiality accompanies a
submission when it is received by the EPA, the submission may be made
available to the public without further notice to the commenter.
Regulated entities. Entities potentially regulated by this action
are those who have the potential to emit HAPs listed in section 112(b)
of the Act in the regulated categories and entities shown in Table 1.
[[Page 14183]]
This table is not intended to be exhaustive, but rather provides a
guide for readers regarding entities likely to be regulated by this
action. This table lists the types of entities that the EPA is now
aware could potentially be regulated by this action. Other types of
entities not listed in this table could also be regulated. To determine
whether your facility is regulated by this action, you should carefully
examine the applicability criteria in Sec. 63.1340 of the proposed
rule. If you have questions regarding the applicability of this action
to a particular entity, consult the person listed in the preceding FOR
FURTHER INFORMATION CONTACT section of this preamble.
Table 1.--Regulated Entities
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Category Examples of regulated entities
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Industry............................... Owners or operators of portland
cement manufacturing plants.
State.................................. Owners or operators of portland
cement manufacturing plants.
Tribal associations.................... Owners or operators of portland
cement manufacturing plants.
Federal agencies....................... None.
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Technology Transfer Network. The proposed regulatory text is also
available on the Technology Transfer Network (TTN), one of EPA's
electronic bulletin boards. The TTN provides information and technology
exchange in various areas of air pollution control. The service is
free, except for the cost of a phone call. Dial (919) 541-5742 for up
to a 14,400 BPS modem. The TTN is also accessible through the Internet
(world wide web) at http://www.epa.gov/ttn/. If more information on the
TTN is needed, call the HELP line at (919) 541-5384. The help desk is
staffed from 11 a.m. to 5 p.m.; a voice menu is available at other
times.
Outline. The information in this preamble is organized as shown
below.
I. Statutory Authority
II. Introduction
A. Background
B. NESHAP for Source Categories
C. Health Effects of Pollutants
D. Portland Cement Manufacturing Industry Profile
III. Summary of Proposed Standards
A. Applicability
B. Emission Limits and Requirements
C. Performance Test and Compliance Provisions
D. Monitoring Requirements
E. Notification, Recordkeeping, and Reporting Requirements
IV. Impacts of Proposed Standards
A. Applicability
B. Air Quality Impacts
C. Water Impacts
D. Solid Waste Impacts
E. Energy Impacts
F. Nonair Health and Environmental Impacts
G. Cost Impacts
H. Economic Impacts
V. Selection of Proposed Standards
A. Selection of Source Category
B. Selection of Emission Sources
1. Feed Preparation Processes (Grinding, Conveying)
2. Feed Preparation Processes (Drying, Blending, Storage)
3. Kiln
4. Clinker Cooler
5. Finish Grinding/Conversion of Clinker to Portland Cement
C. Selection of Pollutants
D. Selection of Proposed Standards for Existing and New Sources
1. Background
2. MACT Floor Technology, Emission Limits, and Format
E. Selection of Testing and Monitoring Requirements
1. Kiln and In-line Kiln Raw Mill PM Emissions
2. Kiln D/F Emissions
3. Kiln and Raw Material Dryer THC Emissions
4. Clinker Cooler PM Emissions
5. Raw and Finish Mill PM Emissions
6. Raw Material Dryer and Materials Handling Processes PM
Emissions
7. General Monitoring Requirements
F. Selection of Notification, Recordkeeping, and Reporting
Requirements
VI. Public Participation
VII. Administrative Requirements
A. Docket
B. Public Hearing
C. Executive Order 12866
D. Enhancing the Intergovernmental Partnership Under Executive
Order 12875
E. Unfunded Mandates Reform Act
F. Regulatory Flexibility Act
G. Paperwork Reduction Act
H. Clean Air Act
I. Statutory Authority
The statutory authority for this proposal is provided by sections
101, 112, 114, 116, 183(f) and 301 of the Clean Air Act, as amended (42
U.S.C. 7401, 7411, 7414, 7416, 7511(f) and 7601).
II. Introduction
A. Background
Nationwide baseline HAP emissions from portland cement
manufacturing plants are estimated to be 260 Mg/yr (290 tpy) at the
current level of control. The HAPs released from kiln systems include
acetaldehyde, arsenic, benzene, cadmium, chromium, chlorobenzene,
dibenzofurans, formaldehyde, hexane, hydrogen chloride, lead,
manganese, mercury, naphthalene, nickel, phenol, polycyclic organic
matter, selenium, styrene, 2,3,7,8-tetrachlorodibenzo-p-dioxin,
toluene, and xylenes. The HAPs released from raw material dryers should
be similar to those from the kiln. The HAPs released from clinker
coolers, raw mills, finish mills, storage bins, conveying system
transfer points, bagging systems and bulk loading and unloading systems
include arsenic, cadmium, chromium, lead, manganese, mercury, nickel,
and selenium. Implementing MACT-level controls is expected to decrease
emissions of these HAPs from existing and projected new sources by
approximately 82 Mg/yr (90 tpy). Plants can achieve this reduction by
upgrading or installing fabric filters (FF), also known as baghouses,
and electrostatic precipitators (ESP) to decrease HAP metals; limiting
temperatures at the particulate matter control device (PMCD) inlet to
decrease dioxin and furan (D/F) emissions; and selecting suitable feed
materials to decrease organic HAP emissions.
The overall effect of these standards would be to improve the
control performance of the industry to the level achieved by the best
performing plants. In addition to the health and environmental benefits
associated with HAP emission reductions, benefits of this action
include a decrease in site-specific emission levels of PM and VOC and
lowered occupational exposure levels for employees.
The nationwide capital and annualized costs of the proposed NESHAP,
including emission controls and associated monitoring equipment, are
estimated at $88 million and $27 million/yr, respectively. The economic
impacts are predicted to increase prices of portland cement by an
average of 1.1 percent.
To minimize adverse impacts, the Agency has proposed controls at
the MACT-floor level, tailored the requirements to allow less-costly
testing and monitoring by using surrogates for HAP emissions and
provided choice in methods of control. The proposed rule
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is ``user friendly,'' with language that is easy to understand by all
of the regulated community. The EPA also proposes to allow existing
facilities up to 3 years to comply. And, as allowed under section
112(i)(3)(B) of the Act, the Administrator or delegated regulatory
authority also may grant 1 additional year if necessary for the
installation of controls.
B. NESHAP for Source Categories
Section 112 of the Act as amended specifically directs the EPA to
develop a list of all categories of major sources and such area sources
as appropriate that emit one or more of the HAPs listed in the Act. The
EPA is further directed to develop NESHAP to control emissions of HAPs
from both existing and new major sources, where a major source is
defined as a source that emits or has the potential to emit 9.1 Mg/yr
(10 tpy) or more of any one HAP or 22.7 Mg/yr (25 tpy) of any
combination of HAPs. The statute requires the standards to reflect the
maximum degree of reduction in HAP emissions that is achievable, taking
into consideration the cost of achieving the emission reduction, any
nonair quality health and environmental impacts, and energy
requirements. This level of control is commonly referred to as MACT.
The control of HAPs is achieved through the promulgation of
technology-based emission standards under sections 112(d) and 112(f)
and work practice standards under 112(h) for categories of sources that
emit HAPs. Emission reductions may be accomplished through the
application of measures, processes, methods, systems, or techniques
including, but not limited to: (1) Reducing the volume of, or
eliminating emissions of, such pollutants through process changes,
substitution of materials, or other modifications; (2) enclosing
systems or processes to eliminate emissions; (3) collecting, capturing,
or treating such pollutants when released from a process, stack,
storage or fugitive emissions point; (4) design, equipment, work
practice, or operational standards (including requirements for operator
training or certification) as provided in subsection (h); or (5) a
combination of the above. [See section 112(d)(2) of the Act.] The EPA
may promulgate more stringent regulations to address residual risk that
remains after the imposition of controls at a later date.
C. Health Effects of Pollutants
The Clean Air Act was created in part to protect and enhance the
quality of the Nation's air resources so as to promote the public
health and welfare and the productive capacity of its population. [See
section 101(b)(1).] In the 1990 Amendments to the Clean Air Act,
Congress specified that each standard for major sources must require
the maximum reduction in emissions of HAPs that EPA determines is
achievable considering cost, health and environmental impacts, and
energy requirements. Title III of the Act establishes a control
technology-based program to reduce stationary source emissions of HAPs.
The goal of section 112(d) (in Title III) is to apply such control
technology to reduce emissions and thereby reduce the hazard of HAPs
emitted from stationary sources.
Section 112(b) of the Act lists HAPs believed to cause adverse
health or environmental effects. The EPA recognizes that the degree of
adverse effects to health can range from mild to severe. The extent and
degree to which the health effects may be experienced is dependent
upon: (1) The ambient concentrations observed in the area (e.g., as
influenced by emission rates, meteorological conditions, and terrain);
(2) the frequency of and duration of exposures; (3) characteristics of
exposed individuals (e.g., genetics, age, pre-existing health
conditions, and lifestyle) which vary significantly with the
population; and (4) pollutant-specific characteristics (e.g., toxicity,
half-life in the environment, bioaccumulation, and persistence). In
essence, these MACT standards would ensure that all major sources of
air toxic emissions achieve the level of control already being achieved
by the better controlled and lower emitting sources in each category.
This approach provides assurance to citizens that each major source of
toxic air pollution will be required to effectively control its
emissions. At the same time, this approach provides a level economic
playing field, ensuring that facilities that employ cleaner processes
and good emissions controls are not disadvantaged relative to
competitors with poorer controls.
Available emission data, collected in conjunction with the
development of this NESHAP, show that non-volatile HAP metals, mercury,
organic HAPs and hydrogen chloride are the predominant HAPs emitted
from portland cement manufacturing plants. These pollutants (except
mercury and hydrogen chloride) have the potential to be reduced by
implementation of the proposed emission limits. In addition to the
HAPs, the portland cement manufacturing NESHAP would also control some
of the pollutants whose emissions are controlled under the National
Ambient Air Quality Standards (NAAQS). These pollutants include PM,
VOC, and lead. The following is a summary of the potential health
effects associated with exposures, at some level, to pollutants that
would be reduced by the standard.
Almost all metals appearing on the section 112(b) list are emitted
from portland cement manufacturing affected sources. There is a wide
range of targets of toxicity for these metals. Effects include skin
irritation, mucous membrane irritation (e.g., lung irritation),
gastrointestinal effects, nervous system effects (including cognitive
effects, tremor, and numbness), increased blood pressure, and
reproductive and developmental effects. Additionally, several of the
metals accumulate in the environment and in the human body. Cadmium,
for example, is a cumulative pollutant which causes kidney effects
after the cessation of exposure. Similarly, the onset of effects from
beryllium exposure may be delayed by months to years. Many of the metal
compounds are also known (arsenic, chromium (VI)) or probable (cadmium,
nickel carbonyl, lead, and beryllium) human carcinogens.
Organic compounds which will potentially be decreased by the
proposed standard include but are not limited to acetaldehyde, benzene,
chlorobenzene, formaldehyde, D/F, hexane, naphthalene, phenol,
polycyclic organic matter, styrene, toluene, and xylenes. Each of these
organic compounds has a range of potential health effects associated
with exposure at some level. Some of the effects associated with short-
term inhalation exposure to these pollutants are similar and include
irritation of the eyes, skin, and respiratory tract in humans; central
nervous system effects (e.g., drowsiness, dizziness, headaches,
depression, nausea, irregular heartbeat); reproductive and
developmental effects; and, neurological effects. Exposure to benzene
at extremely high concentrations may even lead to respiratory
paralysis, coma, or death.
Health effects associated with long-term inhalation exposure in
humans to the organic compounds which will potentially be decreased by
the proposed standard may include mild symptoms such as nausea,
headache, weakness, insomnia, intestinal pain, and burning eyes;
effects on the central nervous system; disorders of the blood; toxicity
to the immune system; reproductive disorders in women (e.g., increased
risk of spontaneous abortion); developmental effects; gastrointestinal
irritation; liver injury; and muscular effects.
[[Page 14185]]
In addition to the non-cancer effects described above, some of the
organic HAPs that would be controlled under this proposed standard are
either known (benzene) or probable (formaldehyde and D/F) human
carcinogens.
Hydrogen chloride (HCl) is highly corrosive to the eyes, skin, and
mucous membranes. Short-term inhalation of HCl by humans may cause
coughing, hoarseness, inflammation and ulceration of the respiratory
tract, as well as chest pain and pulmonary edema. Long-term
occupational exposure of humans to HCl has been reported to cause
inflammation of the stomach, skin, and lungs, and photosensitization.
The health effects of PM, lead, and VOC that would be reduced by
this standard are described in EPA's Criteria Documents, which support
the NAAQS. Briefly, PM emissions have been associated with aggravation
of existing respiratory and cardiovascular disease and increased risk
of premature death. Depending on the degree of exposure, lead can cause
subtle effects on behavior and cognition, increased blood pressure,
reproductive effects, seizures, and even death.
Volatile organic compounds are precursors to the formation of ozone
in the ambient air. At ambient levels, ozone has been shown in human
laboratory and community studies to be responsible for the reduction of
lung function, respiratory symptoms (e.g., cough, chest pain, throat
and nose irritation), increased hospital admissions for respiratory
causes, and increased lung inflammation. Animal studies have shown
increased susceptibility to respiratory infection and lung structure
changes. Exposure to ozone has also been linked to harmful effects on
agricultural crops and forests.
D. Portland Cement Manufacturing Industry Profile
Portland cement is a fine powder, usually gray in color, that
consists of a mixture of the minerals dicalcium silicate, tricalcium
silicate, tricalcium aluminate, and tetracalcium aluminoferrite, to
which one or more forms of calcium sulfate have been added (docket item
II-I-43, p. 746). The primary end use of portland cement is as the key
ingredient in portland cement concrete, which is used in almost all
construction applications.
In 1993, 44 companies operated 118 portland cement plants located
in 37 states. The manufacture of portland cement is covered by SIC code
3241 for hydraulic cements. According to U.S. Small Business
Administration size standards, companies owning portland cement plants
are categorized as small if the total number of employees at the
company is less than 750. Otherwise the company is classified as large.
A total of 7 companies are categorized as small, while the remaining 37
companies are in the large category (docket item II-D-200).
Few new plants are predicted to be constructed during the next 5
years. The EPA estimates that two to four existing plants will undergo
reconstruction in the next 5 years.
All existing kilns and alkali bypasses have PM control devices.
Some existing cement manufacturing plants are required to meet new
source performance standards (NSPS) for PM (40 CFR part 60, subpart F).
The affected facilities to which the NSPS apply are the kiln, kiln gas
alkali bypass, clinker cooler, raw material dryer, and materials
handling processes.
III. Summary of Proposed Standards
A. Applicability
The proposed standards apply to each existing, reconstructed, and
newly constructed portland cement manufacturing plant at any facility
which is a major source or an area source, with the following
exception. Some portland cement plants fire hazardous wastes in the
kiln to provide part or all of the fuel requirement for clinker
production. Portland cement kilns and in-line kiln/raw mills subject to
the NESHAP for hazardous waste combustors 1 (HWC) are not
subject to this standard; however other affected sources at portland
cement plants where hazardous waste is burned in the kiln are subject
to this standard.
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\1\ The EPA proposed regulations for subpart EEE of 40 CFR part
63 on April 19, 1996 at 61 FR 17358.
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For portland cement plants with on-site non-metallic minerals
processing facilities, the first affected source in the sequence of
materials handling operations subject to this proposed NESHAP is the
raw material storage, which is just prior to the raw mill. The primary
and secondary crushers and any other equipment in the non-metallic
minerals processing plant, which precede the raw material storage are
not affected sources under the proposed NESHAP. Furthermore, the first
conveyor system transfer point subject to the proposed NESHAP is the
transfer point associated with the conveyor transferring material from
the raw material storage to the raw mill. Conveyor system transfer
points prior to this conveyor are not affected sources under this
proposed NESHAP (docket item II-B-53).
This regulation does not apply to the emissions from cement kiln
dust (CKD) storage facilities (i.e., CKD piles or landfills). A
separate rulemaking will be forthcoming from EPA's Office of Solid
Waste (OSW) that will apply to air emissions associated with CKD
management and disposal facilities.
Except for hazardous waste burning (HW) cement kilns and HW in-line
kiln/raw mills, EPA is proposing to apply these standards to all cement
kilns and in-line kiln/raw mills regardless of the material being
combusted in the kiln. This proposal, however, does not preclude EPA
from determining that cement kilns combusting solid waste materials
should be regulated under section 129 of the Clean Air Act, 42 U.S.C.
7429, and to revise the applicability section of these regulations
accordingly at the time section 129 regulations applicable to cement
kilns are promulgated.
The EPA believes that applying this regulation to all non-hazardous
waste burning (NHW) cement kilns regardless of the material combusted
in the kiln is necessary at this time due to the Court of Appeals for
the District of Columbia's recent decision in Davis County Solid Waste
Management District v. Environmental Protection Agency, 101 F.3d 1395
(D.C. Cir. 1996) (petition to review municipal waste combustor
(``MWC'') regulations promulgated on December 19, 1995 pursuant to
section 129 of the Act, 60 FR 65387). In the applicability section of
the MWC regulations, EPA applied the standards to all solid waste
incineration units combusting more than 30-percent municipal solid
waste. Two owners and operators of MWC units with capacity less than
250 tons/day filed petitions for review on the grounds that EPA
improperly had included their units in the large category. The Cement
Kiln Recycling Coalition (``CKRC'') also filed a petition for review on
the grounds that the standards should not apply to cement kilns. In its
opinion dated December 6, 1996, the Court indicated its intent to
vacate the standards in their entirety on the grounds raised by the two
petitioners who own and operate MWC units; as a result, the Court did
not reach the issue raised by CKRC. Accordingly, EPA believes that it
is appropriate to apply these regulations as a gap-filling measure to
control emissions from NHW cement kilns and in-line kiln/raw mills
regardless of the material combusted in the kiln (except for hazardous
waste) until EPA determines whether regulations applicable to cement
kilns combusting solid waste materials should be re-promulgated under
section 129. To
[[Page 14186]]
decide otherwise would have the potential effect of allowing cement
kiln owners and operators to avoid regulation by adding some solid
waste material to the cement kiln.
As background, section 129(a)(1)(A) requires the Administrator to
establish performance standards and other requirements pursuant to
section 111 and section 129 of the Act for each category of solid waste
incineration units [42 U.S.C. 7429(a)(1)(A)]. Whereas section 112(c) of
the Act requires EPA to determine major and area sources of the 188
hazardous air pollutants (HAPs) listed in section 112(b), Congress
specifically listed in section 129 various categories of solid waste
incineration units that EPA must regulate, including solid waste
incineration units combusting municipal solid waste [sections
129(a)(1)(B) and (C)], solid waste incineration units combusting
hospital waste, medical waste, and infectious waste [section
129(a)(1)(C)], solid waste incineration units combusting commercial or
industrial waste [section 129(a)(1)(D)], and ``other categories of
solid waste incineration units'' which are to be defined by EPA [42
U.S.C. 7429(a)(1)].
Section 129(g)(1) of the Act broadly defines a solid waste
incineration unit (``SWIU'') as ``a distinct operating unit of any
facility which combusts any solid waste material from commercial or
industrial establishments or the general public * * *.'' 42 U.S.C.
7429(g)(1) (emphasis added). Section 129(g)(1) expressly states that
``incinerators or other units required to have a permit under section
3005 of the Solid Waste Disposal Act, 42 U.S.C. 6925'' shall not be
considered a SWIU. That section also expressly excludes from the
definition of SWIU the following units:
(A) materials recovery facilities (including primary or
secondary smelters) which combust waste for the primary purpose of
recovering metals, (B) qualifying small power production facilities,
as defined in section 769(17)(C) of Title 16, or qualifying
cogeneration facilities as defined in section 796(18)(B) of Title
16, which burn homogeneous waste (such as units which burn tires or
used oil, but not including refuse-derived fuel) for the production
of electric energy or in the case of qualifying cogeneration
facilities which burn homogenous waste for the production of
electric energy (such as heat) which are used for industrial,
commercial, heating or cooling purposes, or (C) air curtain
incinerators provided that such incinerators only burn wood wastes,
yard wastes and clean lumber and that such air curtain incinerators
comply with opacity limitations to be established by the
Administrator by rule.
42 U.S.C. 7429(g)(1). Accordingly, with the exception of those solid
waste incineration units that are expressly excluded from regulation by
section 129(g)(1), Congress intended EPA to establish regulations for
all SWIU's under section 129. This includes cement kilns that combust
solid waste materials, including refuse-derived fuel.
Section 129 is similar to section 112 of the Act in that both
require EPA to establish performance standards that are based upon the
performance of maximum achievable control technology (MACT). Section
112(b), however, lists 188 hazardous air pollutants (HAPs) for
potential regulation, and section 112(c)(6) requires EPA to establish
performance standards under section 112(d) for categories of sources
emitting seven specific pollutants, including the following HAPs
emitted by cement kilns: mercury and dioxins/dibenzofurans [42 U.S.C.
7412]. By comparison, section 129 expressly requires EPA to regulate
emissions of the following criteria pollutants and HAPs--particulate
matter, opacity (as appropriate), sulfur dioxide, hydrogen chloride,
nitrogen oxides, carbon monoxide, lead, cadmium, mercury, and dioxins
and dibenzofurans [42 U.S.C. 7429(a)(4)]. Section 129 also gives EPA
the discretion to promulgate emission limitations or provide for the
monitoring of postcombustion concentrations of surrogate substances or
any other pollutant not expressly listed for regulation in section
129(a)(4). [See 42 U.S.C. 7429(a)(4).] In addition, section 129
contains other requirements not contained in section 112, such as
operator training requirements. [See 42 U.S.C. 7429(d).]
As stated previously, the regulations being proposed today are
pursuant to section 112 of the Act and apply to all cement kilns except
portland cement kilns and in-line kiln/raw mills that would be subject
to the NESHAP for hazardous waste combustors. In today's notice, the
EPA is proposing to establish emission limitations for particulate
matter (as a surrogate for metals, except mercury), dioxins/furans, and
total hydrocarbons (as a surrogate for organic HAPs) regardless of the
material being combusted in the cement kiln. If EPA determines that
additional regulations are required under section 129 for cement kilns
that combust solid waste materials (e.g., cement kilns combusting
materials containing more than 30-percent municipal solid waste or
cement kilns combusting medical waste), then such regulations will be
promulgated under section 129 and EPA will state clearly in the
applicability section of those regulations when those standards apply
and revise the applicability section of these regulations accordingly.
At no time, will a cement kiln be expected to comply simultaneously
with regulations promulgated pursuant to section 112 and regulations
promulgated pursuant to section 129. Section 129(h)(1) expressly states
that no solid waste incineration unit subject to performance standards
under section 129 and section 111 shall be subject to standards under
section 112(d) of the Act [42 U.S.C. 7429(h)(1)]. The EPA reads this
provision to mean that for emissions potentially subject to section
129, the Agency must elect whether to cover such emissions under that
section, or under section 112. If EPA elects to cover emissions under
section 129, those emissions must be excluded from regulation under
section 112. For example, if a cement kiln combusts only fossil fuels,
it would have to comply with the regulations being proposed today. If
the kiln combusts a mixture of 50% coal and 50% non-hazardous solid
waste, it would continue to comply with the regulations being proposed
today until EPA promulgates regulations applicable to such kilns under
section 129 of the Act. At that time, if the kiln is burning the 50%
coal and 50% solid waste mixture, it would have to comply with the
section 129 regulations as long as it continued to combust solid waste
material. Thus, in the same way that installation of a particular type
of combustion device determines which regulation is applicable,
combustion of certain materials in that combustion device would
determine whether the section 112 regulation or section 129 regulation
is applicable.
The EPA does not believe that this approach will subject cement
kiln owners to duplicative regulations. As noted earlier, regulations
under section 112 and section 129 are based on MACT. If EPA determines
that additional regulations under section 129 are appropriate because
cement kilns are combusting solid waste material, EPA would be required
to promulgate additional MACT standards for the following pollutants
pursuant to section 129(a)(4): opacity, sulfur dioxide, hydrogen
chloride, nitrogen oxides, carbon monoxide, lead, cadmium, and mercury.
The EPA also would determine whether the standards for particulate
matter, total hydrocarbon, and dioxins/furans should be revised for
kilns combusting solid waste materials [42 U.S.C. 7429(a)(4)].
B. Emission Limits and Requirements
The proposed NESHAP for portland cement manufacturing would apply
to both major and area sources of HAPs.
[[Page 14187]]
The affected sources for which emission limits are proposed include the
kiln, in-line kiln/raw mill, clinker cooler, raw material dryer, and
materials handling processes that include the raw mill, finish mill,
raw material storage, clinker storage, finished product storage,
conveyor transfer points, bagging and bulk loading and unloading
systems (hereafter referred to as materials handling processes).
The proposed NESHAP would limit emissions of HAPs from non-
hazardous waste (NHW) portland cement kilns, NHW in-line kiln/raw
mills, and NHW kiln alkali bypasses. Kiln emission limits would not
apply to kilns or in-line kiln/raw mills that will be subject to the
NESHAP for various hazardous waste combustor (HWC) types, including
cement kilns which burn hazardous waste.2
---------------------------------------------------------------------------
\2\ The EPA proposed regulations for subpart EEE of 40 CFR part
63 on April 19, 1996 at 61 FR 17358.
---------------------------------------------------------------------------
The kiln emission limits would apply to the kiln and in-line kiln/
raw mill gases and to kiln alkali bypass gases (which may or may not be
discharged through a separate stack).
The proposed rule would limit emissions of HAPs from raw material
dryers, clinker coolers and materials handling processes, regardless of
the type of fuel burned in the kiln. The proposed rule would limit PM
(surrogate for non-volatile HAP metals) emissions from new and existing
NHW kilns, NHW in-line kiln/raw mills, and clinker coolers at portland
cement plants which are major sources. Particulate matter emitted from
portland cement manufacturing contains quantities of metal HAPs such as
compounds of arsenic, cadmium, chromium, lead, manganese, mercury,
nickel, and selenium. Controlling PM emissions would also control
emissions of HAP metals. A surrogate approach is used for particulate
metal HAPs in the proposed NESHAP to allow easier and less expensive
measurement, analysis, and monitoring requirements, and because the
control techniques for non-volatile metal HAPs are the same as the
control techniques for PM. Although trace amounts of mercury may be
found in the particulate matter, it is generally considered a volatile
metal, and appreciable reductions of mercury emissions are not expected
through the use of PM controls. Opacity limits would also apply to NHW
kilns, NHW in-line kiln/raw mills, clinker coolers, raw material
dryers, and materials handling processes.
The proposed rule also would limit D/F emissions from new and
existing NHW kilns and NHW in-line kiln/raw mills located at portland
cement plants which are major or area sources of HAPs. In addition, the
rule would limit total hydrocarbon (THC) as a surrogate for organic HAP
emissions from new NHW kilns, new NHW in-line kiln/raw mills, and new
raw material dryers at portland cement plants which are major sources.
Kiln, in-line kiln/raw mill, and raw material dryer organic emissions
contain various organic HAPs including, but not limited to,
acetaldehyde, benzene, formaldehyde, hexane, naphthalene, styrene,
toluene, and xylenes. Tables 2 and 3 present a summary of the proposed
emission limits for new and existing portland cement affected sources.
Table 2.--Summary of Proposed Emission Limitsa for Affected Sources at
Portland Cement Plants
[Metric units]
------------------------------------------------------------------------
Affected source and Emission limit for Emission limit for
pollutant existing sources new sources
------------------------------------------------------------------------
NHW kiln and NHW in-line 0.15 kg/Mg dry feedd 0.15 kg/Mg dry feedd
kiln/raw mill b PM. and opacity levelb and opacity levelb
no greater than 20 no greater than 20
percent. percent.
NHW kiln and NHW in-line 0.2 ng TEQ/dscm or 0.2 ng TEQ/dscm or
kiln/raw mill D/F b, c. 0.4 ng TEQ/dscm 0.4 ng TEQ/dscm
with PM control with PM control
device operated at device operated at
204 deg. 204 deg.
C. C.
NHW kiln and NHW in-line None................ 50 ppmvd (as
kiln/raw mill THC. propane).
Clinker cooler PM........... 0.05 kg/Mg dry feed 0.05 kg/Mg dry feed
and opacity level and opacity level
no greater than 10 no greater than 10
percent. percent.
Raw material dryer and 10 percent opacity.. 10 percent opacity.
materials handling
processes (raw mill system,
finish mill system, raw
material storage, clinker
storage, finished product
storage, conveyor transfer
points, bagging, and bulk
loading and unloading
systems) PM.
Raw material dryer THC...... None................ 50 ppmvd (as
propane).
------------------------------------------------------------------------
a All concentration limits at 7 percent oxygen.
b Includes main and alkali bypass stacks.
c Applies to both major and area source portland cement plants.
d If there is an alkali bypass stack associated with the kiln or in-line
kiln/raw mill, the combined PM emission from the kiln or in-line kiln/
raw mill and the alkali bypass must be less than 0.15 kg/Mg dry feed.
Table 3.--Summary of Proposed Emission Limits a for Affected Sources at
Portland Cement Plants
[English Units]
------------------------------------------------------------------------
Affected source and Emission limit for Emission limit for
pollutant existing sources new sources
------------------------------------------------------------------------
NHW kiln and NHW in-line 0.30 lb/ton dry feed 0.30 lb/ton dry feed
kiln/raw mill b PM. d and opacity level d and opacity level
b no greater than b no greater than
20 percent. 20 percent.
NHW kiln and NHW in-line 8.7 x 10-11 gr TEQ/ 8.7 x 10-11 gr TEQ/
kiln/raw mill D/F b, c. dscf or 1.7 x 10-10 dscf or 1.7 x 10-10
gr TEQ/dscf with PM gr TEQ/dscf with PM
control device control device
operated at 400 deg.F. eq>400 deg.F.
NHW kiln and NHW in-line None................ 50 ppmvd (as
kiln/raw mill THC. propane).
Clinker cooler PM........... 0.10 lb/ton dry feed 0.10 lb/ton dry feed
and opacity level and opacity level
no greater than 10 no greater than 10
percent. percent.
[[Page 14188]]
Raw material dryer and 10 percent opacity.. 10 percent opacity.
materials handling
processes (raw mill system,
finish mill system, raw
material storage, clinker
storage, finished product
storage, conveyor transfer
points, bagging, and bulk
loading and unloading
systems) PM.
Raw material dryer THC...... None................ 50 ppmvd (as
propane).
------------------------------------------------------------------------
a All concentration limits at 7 percent oxygen.
b Includes main and alkali bypass stacks.
c Applies to both major and area source portland cement plants.
d If there is an alkali bypass stack associated with the kiln or in-line
kiln/raw mill, the combined PM emission from the kiln or in-line kiln/
raw mill and the alkali bypass must be less than 0.30 lb/ton dry feed.
C. Performance Test and Compliance Provisions
A performance test would be required to demonstrate initial
compliance with each applicable numerical limit. Under the proposed
standard, the owner or operator would use EPA Method 5, ``Determination
of Particulate Emissions from Stationary Sources'' to measure PM
emissions from kilns, in-line kiln/raw mills and clinker coolers. These
tests would be repeated every 5 years. Kilns and in-line kiln/raw mills
equipped with alkali bypasses would be required to meet the particulate
standard based on combined emissions from the kiln exhaust and the
alkali bypass. Owners or operators of in-line kiln/raw mills would be
required to conduct a Method 5 performance test while the raw mill is
operating and a separate Method 5 performance test while the raw mill
is not operating. In conducting the Method 5 tests, a determination of
the particulate matter collected in the impingers (``back half'') of
the particulate sampling train would not be required.
The opacity exhibited during the period of the initial Method 5
performance test would be determined, if feasible, through the use of a
continuous opacity monitor (COM). Where the control device exhausts
through a monovent or where the use of a COM in accordance with the
installation specifications of EPA Performance Specification (PS)-1 of
appendix B to 40 CFR part 60, is not feasible, EPA Method 9, ``Visual
Determination of the Opacity of Emissions from Stationary Sources''
would be used. Where the control device discharges through a FF with
multiple stacks or an ESP with multiple stacks, the owner or operator
would have the option of conducting an opacity test in accordance with
Method 9, in lieu of installing a COM.
Under the proposed standard, the owner or operator would use EPA
Method 23, ``Determination of Polychlorinated Dibenzo-p-dioxins and
Polychlorinated Dibenzofurans from Stationary Sources'' to measure D/F
emissions from kilns and in-line kiln/raw mills. These tests would be
repeated every 5 years. The temperature at the inlet to the PMCD during
the period of the Method 23 performance test would be continuously
recorded. If carbon injection is used for D/F control the carbon
injection rate during the period of the Method 23 performance test
would be monitored. Owners or operators of in-line kiln/raw mills would
be required to conduct a Method 23 performance test, and monitor the
temperature at the inlet to the PMCD while the raw mill is operating,
and a separate Method 23 performance test and inlet temperature
monitoring while the raw mill is not operating. If applicable, the
carbon injection rate would be monitored during both performance tests.
Where applicable, the exhausts from both the kiln or in-line kiln/raw
mill and the alkali bypass would be required to meet the D/F standard.
Under the proposed standard, the owner or operator would use a THC
continuous emission monitor (CEM) to continuously measure THC emissions
from new or reconstructed kilns, new or reconstructed in-line kiln/raw
mills, and new raw material dryers. Owners or operators of new or
reconstructed in-line kiln/raw mills would be required to demonstrate
initial compliance by measuring THC emissions while the raw mill is
operating and while the raw mill is not operating. The proposed
standard for THC does not apply to the exhaust from the alkali bypass
of kilns or in-line kiln/raw mills. Each THC CEM would be required to
be designed, installed, and operated in accordance with EPA Performance
Specification (PS)-8A of 40 CFR part 60, appendix B. 3
---------------------------------------------------------------------------
\3\ The EPA proposed amendments to appendix B of 40 CFR part 60
on April 19, 1996 at 61 FR 17358.
---------------------------------------------------------------------------
Under the proposed standard, the owner or operator would use EPA
Method 9, ``Visual Determination of the Opacity of Emissions from
Stationary Sources'' to measure the opacity of gases discharged from
raw mills, finish mills, raw material dryers and materials handling
processes. These tests would be repeated every five years. A summary of
proposed compliance and monitoring options is given in Table 4.
Table 4.--Summary of Proposed Compliance Demonstration and Monitoring
Requirements
------------------------------------------------------------------------
Affected source and Compliance Monitoring
pollutant demonstration requirement
------------------------------------------------------------------------
New and existing NHW kiln EPA Method 5 a...... COM if feasible d, e
and NHW in-line kiln/raw or daily EPA Method
mill b, c PM. 9 visual opacity
readings.
New and existing NHW kiln EPA Method 23 a..... Monitor temperature
and NHW in-line kiln/raw at inlet to PM
mill b, c, h, i D/F. control device f
and minimum carbon
injection rate if
activated carbon
injection is used.
[[Page 14189]]
New NHW kiln and NHW in-line THC CEM (EPA PS-8A) THC CEM (EPA PS-8A)
kiln/raw mill THC. j. j
New and existing clinker EPA Method 5 a...... COM d, g or daily
cooler PM. EPA Method 9 visual
opacity readings.
New and existing raw and EPA Method 9 a, g... Daily EPA Method 22
finish mill PM. visual opacity
readings or
operation of bag
break detectors.
New and existing raw EPA Method 9 a, g... None.
material dryer and
materials handling
processes (raw mill system,
finish mill system, raw
material storage, clinker
storage, finished product
storage, conveyor transfer
points, bagging, and bulk
loading and unloading
systems) PM.
New raw material dryer THC.. THC CEM (EPA PS-8A) THC CEM (EPA PS-8A)
j. j
------------------------------------------------------------------------
a Required initially and every 5 years thereafter.
b Includes main exhaust and alkali bypass.
c In-line kiln/raw mill to be tested with and without raw mill in
operation.
d Must meet COM performance specification criteria. If the fabric filter
or electrostatic precipitator has multiple stacks, daily EPA Method 9
visual opacity readings may be taken instead of using a COM.
e Opacity limit is 20 percent. Corrective action trigger is 15 percent.
f Site-specific temperature limit at APCD inlet is established during
successful D/F emissions testing.
g Opacity limit is 10 percent.
h Alkali bypass is tested with the raw mill on.
i Temperature parameters determined separately with and without the raw
mill operating.
j EPA Performance Specification (PS)-8A. Proposed on April 19, 1996 at
61 FR 17358.
D. Monitoring Requirements
The proposed rule requires owners or operators to monitor the
opacity of gases discharged from kilns, in-line kiln/raw mills, alkali
bypasses and clinker coolers using a COM, if a COM can be feasibly
installed in accordance with PS-1 of appendix B to 40 CFR part 60.
Where it is not feasible to install a COM, e.g., where the control
device discharges through a monovent, the owner or operator would be
required to monitor emissions by conducting daily Method 9 tests. Where
the control device discharges through an FF with multiple stacks or an
ESP with multiple stacks, the owner or operator would have the option
of conducting daily tests in accordance with Method 9, in lieu of
installing a COM. The duration of the Method 9 tests would be 30
minutes. Owners or operators would also be required to determine kiln
or in-line kiln/raw mill feed rate.
The opacity limit for kilns and in-line kiln/raw mills would be 20
percent. Any 30-minute average opacity reading greater than 20 percent
determined by the COM or daily Method 9 test would be a violation of
the standard. Any ten consecutive 30-minute average COM readings
exceeding 15 percent, or any single 30-minute average Method 9 reading
exceeding 15 percent would trigger a site-specific operating and
maintenance plan, incorporated within the owner or operator's part 70
permit. The owner or operator would be required to initiate the site-
specific operating and maintenance plan within one hour. If the opacity
exceeds 15 percent for five percent of the operating time as determined
by 30-minute average COM readings, or if the 30-minute average readings
exceed 15 percent during five percent of the daily Method 9 tests,
during any 180 day reporting period, the owner or operator would be
required to develop and implement a quality improvement plan (QIP)
consistent with subpart D of the draft approach to compliance assurance
monitoring.4 The owner or operator would be required to
implement the QIP as expeditiously as possible but in no case would the
period for completing the implementation of the plan exceed 180 days.
If the owner or operator determined that more than 180 days was
required to complete the appropriate improvements, the owner or
operator would be required to notify the permitting authority and
obtain a site-specific resolution subject to the approval of the
permitting authority.
---------------------------------------------------------------------------
\4\ The EPA announced its intention to propose subpart D of 40
CFR part 64 on August 13, 1996 at 61 FR 41991.
---------------------------------------------------------------------------
The opacity limit for clinker coolers would be 10 percent, based on
any 30-minute average COM or Method 9 reading.
The proposed rule requires the owner or operator to monitor D/F
emissions from kilns and in-line kiln/raw mill systems and to maintain
the temperature at the inlet to the PMCD at a level no greater than
either: (1) the higher of 400 deg.F or the level established during
the successful Method 23 performance test plus five percent (not to
exceed 25 deg.F) of the temperature measured in deg.F during the
successful compliance test, if D/F emissions were determined to be no
greater than 0.15 ng toxic equivalent (TEQ)/dscm (6.5 x
10-11 gr/dscf); (2) the higher of 400 deg.F or the level
established during the successful Method 23 performance test, if D/F
emissions were determined to be greater than 0.15 ng TEQ/dscm (6.5 x
10-11 gr/dscf) but less than 0.2 ng TEQ/dscm (8.7 x
10-11 gr/dscf); or (3) 400 deg.F if D/F emissions were
greater than 0.2 ng TEQ/dscm (8.7 x 10-11 gr/dscf) but
less than or equal to 0.4 ng TEQ/dscm (1.7 x 10-10 gr/
dscf).
Owners or operators of in-line kiln/raw mills would be required to
establish separate PMCD inlet temperatures applicable to periods when
the raw mill is operating and periods when the raw mill is not
operating. The appropriate ``raw mill operating status dependent'' PMCD
inlet temperature could not be exceeded. Owners or operators of kilns
or in-line kiln/raw mills equipped with alkali bypasses would be
required to establish separate temperatures for the inlet to the kiln
or in-line kiln raw mill exhaust PMCD and the kiln or in-line kiln
alkali bypass PMCD.
If carbon injection is used for D/F control, the carbon injection
rate would be monitored, and maintained at a level equaling or
exceeding the rate which existed during the successful Method 23
performance test.
The proposed rule requires the owner or operator to monitor THC
emissions from the main exhaust of new and reconstructed kilns; the
main exhaust of new and reconstructed in-line kiln/raw mills; and new
and reconstructed raw
[[Page 14190]]
material dryers using a CEM installed in accordance with PS-8A in 40
CFR part 60, appendix B.5
---------------------------------------------------------------------------
\5\ The EPA proposed amendments to appendix B of 40 CFR part 60
on April 19, 1996 at 61 FR 17358.
---------------------------------------------------------------------------
The proposed rule requires the owner or operator to monitor the
opacity from raw mills and finish mills either by conducting a daily
six-minute test in accordance with Method 22, ``Visual Determination of
Fugitive Emissions from Material Sources and Smoke Emissions from
Flares'', or by installing, calibrating, operating and maintaining a
bag break detection system. In the event that fugitive emissions are
observed during the Method 22 test, the owner or operator would be
required to conduct a 30-minute Method 9 test commencing within 24
hours of the end of the Method 22 test. In addition, the owner or
operator would be required to initiate, within one hour, a site-
specific operating and maintenance plan developed as part of the
application for a part 70 permit.
In the event that the bag break detection system alarm were
triggered, the owner or operator would be required to initiate, within
one hour, a site-specific operating and maintenance plan developed as
part of the application for a part 70 permit.
As required by the NESHAP general provisions (40 CFR part 63,
subpart A), the owner or operator also must develop and implement a
startup, shutdown, and malfunction plan.
E. Notification, Recordkeeping, and Reporting Requirements
All notification, recordkeeping, and reporting requirements in the
general provisions (40 CFR part 63, subpart A) would apply to portland
cement manufacturing plants. These include: (1) Initial notification(s)
of applicability, notification of performance test, and notification of
compliance status; (2) a report of performance test results; (3) a
startup, shutdown, and malfunction plan with semiannual reports of
reportable events (if they occur); and (4) semiannual reports of excess
emissions. If excess emissions are reported, the owner or operator
would report quarterly until a request to return the reporting
frequency to semiannual is approved.
Owners and operators would also be required to prepare an operation
and maintenance plan for kiln, in-line kiln/raw mill, raw mill and
finish mill APCDs consistent with subpart D of the draft approach to
compliance assurance monitoring (CAM).6 The operation and
maintenance plan would become part of their operating permit required
by 40 CFR part 70.
---------------------------------------------------------------------------
\6\ The EPA announced its intention to propose subpart D of 40
CFR part 64 on August 13, 1996 at 61 FR 41991.
---------------------------------------------------------------------------
Under circumstances described in section III. D. of this preamble,
kiln and in-line kiln/raw mill monitoring may trigger a requirement to
prepare and implement a site-specific Quality Improvement Program
(QIP), that will also be consistent with the draft CAM
rule.7 Owners or operators would be required to report if a
QIP were required, and to notify the permitting authority if a required
QIP would take more than 180 days to implement.
---------------------------------------------------------------------------
\7\ The EPA announced its intention to propose subpart D of 40
CFR 64 on August 13, 1996 at 61 FR 41991.
---------------------------------------------------------------------------
The NESHAP general provisions (40 CFR part 63, subpart A) require
that records be maintained for at least 5 years from the date of each
record. The owner or operator must retain the records onsite for at
least 2 years but may retain the records offsite the remaining 3 years.
The files may be retained on microfilm, microfiche, on a computer disk,
or on magnetic tape. Reports may be made on paper or on a labeled
computer disk using commonly available and compatible computer
software.
IV. Impacts of Proposed Standards
A. Applicability
The EPA estimates that there are currently 118 portland cement
plants in the United States. All portland cement plants would be
subject to the proposed standards. The following sources would be
affected when located at a portland cement plant that is a major
source:
(1) New, reconstructed, and existing NHW kilns and NHW in-line
kiln/raw mills including alkali bypasses that are not subject to the
HWC NESHAP 8 would be subject to emission limits for PM, D/
F, and opacity;
---------------------------------------------------------------------------
\8\ The EPA proposed regulations for subpart EEE of 40 CFR part
63 on April 19, 1996 at 61 FR 17358.
---------------------------------------------------------------------------
(2) New and reconstructed NHW kiln main exhausts and new and
reconstructed NHW in-line kiln/raw mills main exhausts, that are not
subject to the HWC NESHAP,9 would be subject to an emission
limit for THC;
---------------------------------------------------------------------------
\9\ The EPA proposed regulations for subpart EEE of 40 CFR part
63 on April 19, 1996 at 61 FR 17358.
---------------------------------------------------------------------------
(3) New and reconstructed raw material dryers would be subject to
an emission limit for THC;
(4) New, reconstructed, and existing clinker coolers would be
subject to emission limits for PM and opacity; and
(5) New, reconstructed, and existing raw material dryers, raw and
finish mills, and material handling processes would be subject to an
opacity limit.
The following sources would be affected when located at a portland
cement plant that is an area source: new, reconstructed, and existing
NHW kilns and NHW in-line kiln/raw mills, including alkali bypasses,
that are not subject to the HWC NESHAP,10 would be subject
to emission limits for D/F.
---------------------------------------------------------------------------
\10\ The EPA proposed regulations for subpart EEE of 40 CFR part
63 on April 19, 1996 at 61 FR 17358.
---------------------------------------------------------------------------
B. Air Quality Impacts
Nationwide baseline HAP emissions from portland cement
manufacturing plants are estimated to be 260 Mg/yr (290 tpy) at the
current level of control. The proposed standards would reduce emissions
of HAPs by 82 Mg/yr (90 tpy) from baseline levels. Estimates of annual
emissions of HAPs and expected reductions from implementation of the
proposed standards are given in metric and English units in Tables 5
and 6 (docket item II-B-76, docket item II-B-77). The following text
reviews the information provided in Tables 5 and 6.
Table 5.--Nationwide Annual Emissions of HAPS and Other Pollutants From Portland Cement Manufacturing Plants
[Metric units]
----------------------------------------------------------------------------------------------------------------
Baseline emissions (Mg/ Emission reduction
Source Pollutant yr) (Mg/yr)
----------------------------------------------------------------------------------------------------------------
Kilns, in-line kiln/raw mills, and HAP Metals a............... 150................... 35.
alkali bypasses.
PM a....................... 14,000................ 3,400.
D/F (TEQ) b................ 44 g/yr............... 16 g/yr.
Organic HAPs c............. 120................... 47.
THC c...................... 530................... 200.
[[Page 14191]]
Clinker coolers.................... HAP Metals a............... 1.1................... 0.18.
PM a....................... 8,100................. 1,300.
----------------------------------------------------------------------------------------------------------------
a These numbers pertain to existing sources only.
b These numbers pertain to both new and existing NHW kilns.
c These numbers pertain to new NHW kilns only.
Table 6.--Nationwide Annual Emissions of HAPS and Other Pollutants From Portland Cement Manufacturing Plants
[English units]
----------------------------------------------------------------------------------------------------------------
Baseline emissions Emission reduction
Source Pollutant (tpy) (tpy)
----------------------------------------------------------------------------------------------------------------
Kilns, in-line kiln/raw mills, and HAP Metalsa................ 160................... 38.
alkali bypasses.
PMa........................ 16,000................ 3,800.
D/F (TEQ)b................. 0.096 lbs/yr.......... 0.035 lbs/yr.
Organic HAPsc.............. 130................... 52.
THCc....................... 580................... 220.
Clinker coolers.................... HAP Metalsa................ 1.2................... 0.2.
PMa........................ 8,800................. 1,400.
----------------------------------------------------------------------------------------------------------------
a These numbers pertain to existing sources only.
b These numbers pertain to both new and existing NHW kilns.
c These numbers pertain to new NHW kilns only.
The proposed MACT standards would reduce PM emissions from the
existing NHW cement kilns and in-line kiln/raw mills by 3,400 Mg/yr
(3,800 tpy) from the baseline level, a reduction of 24 percent.
Emissions of HAP metals from the affected existing NHW cement kilns and
in-line kiln/raw mills would be reduced by 35 Mg/yr (38 tpy), a
reduction of 24 percent from the baseline level. Emissions of D/F TEQ
would be reduced by 15 grams (g)/yr (0.033 lb/yr), a reduction of 36
percent from the baseline level, at existing NHW cement kiln and in-
line kiln/raw mills.
For new NHW cement kilns and in-line kiln/raw mills, the MACT
standards are projected to reduce emissions of D/F TEQ by an average of
0.6 g/yr (0.001 lb/yr) over the next 5 years (from major and area
sources), a 36 percent reduction from projected baseline emissions. For
new kilns, the proposed standards would also reduce projected emissions
of THC by an average of 200 Mg/yr (220 tpy) and organic HAPs by an
average of 47 Mg/yr (52 tpy) over the next 5 years, an emissions
reduction for each of 39 percent from corresponding estimated
nationwide baseline emissions (docket item II-B-76).
The proposed MACT standards would reduce PM emissions from 35
percent of the existing clinker coolers by 1,300 Mg/yr (1,400 tpy) from
the baseline level, a reduction of 16 percent. Emissions of HAP metals
from the affected existing clinker coolers would be decreased by 0.18
Mg/yr (0.2 tpy), a reduction of 16 percent from the baseline level.
Additional reductions of THC and organic HAPs will result from the
MACT standards for new raw material dryers. However, information on THC
emission rates from raw material dryers and the number of such affected
sources is not currently available, so nationwide reductions cannot be
estimated.
The MACT standards would also reduce PM emissions from raw material
dryers, and other material handling processes. However, no impacts were
estimated for these affected sources because there is no available
information on typical PM emissions from the affected sources that do
not meet the NSPS, and no information on the number of sources
potentially affected by this MACT standard.
C. Water Impacts
Control of D/F emissions using water injection for temperature
reduction would result in an estimated increased water consumption
(evaporated into the kiln exhaust gas for cooling) of 190 million
gallons per year for existing NHW kilns and NHW in-line kiln/raw mills
of 8 million gallons per year for new NHW kilns and NHW in-line kiln/
raw mills (docket item II-B-77).
D. Solid Waste Impacts
The amount of solid waste from existing NHW kilns, in-line kiln/raw
mills, and clinker coolers (located at major sources) would increase by
an estimated 4,700 Mg/yr (5,200 tpy) due to the proposed standard for
PM control (docket item II-B-77).
E. Energy Impacts
For existing NHW kilns and NHW in-line kiln/raw mills the proposed
MACT standards for PM and D/F would increase energy consumption by an
estimated 11 million kilowatt hours (KWh)/yr [38 billion British
thermal units (Btu)/yr]. For new NHW kilns and NHW in-line kiln/raw
mills the proposed MACT standards for D/F would increase energy
consumption by an estimated (docket item II-B-77) 10,600 KWh/yr (36
million Btu/yr).
F. Nonair Health and Environmental Impacts
The reduction in HAP emissions would have a beneficial effect on
nonair health and environment impacts. D/F and HAP metals have been
found in the Great Lakes and have been listed as pollutants of concern
due to their persistence in the environment, potential to
bioaccumulate, and toxicity to humans and the environment (docket item
II-A-31, pp. 18 to 21). Implementation of the proposed
[[Page 14192]]
NESHAP would aid in reducing aerial deposition of these emissions.
Occupational exposure limits under 29 CFR part 1910 are in place
for some of the regulated HAPs (and surrogates) except D/F. The
National Institute for Occupational Safety and Health recommends an
exposure level for D/F at the lowest feasible concentration (docket
item II-I-45, p. 124). The proposed NESHAP would reduce emissions, and
consequently, occupational exposure levels for plant employees.
G. Cost Impacts
For existing NHW kilns, NHW in-line kilns/raw mills, clinker
coolers, raw and finish mills, and materials handling facilities, the
projected total capital costs (including estimated monitoring costs) of
the proposed standard for controlling emissions of PM and D/F are $87
million. The projected annual costs (including monitoring costs) for
these controls are $27 million. For new NHW kilns and NHW in-line kiln/
raw mills, the projected total capital and annual costs of the MACT
standard for D/F are $390,000 and $89,000, respectively. No capital and
annual costs are projected for new and reconstructed NHW kilns, NHW in-
line kilns/raw mills, and clinker coolers as a result of the proposed
standard for PM because these sources will be required to comply with
the existing NSPS for portland cement plants (40 CFR part 60, subpart
F). The proposed THC emissions limit for new NHW kilns and NHW in-line
kiln/raw mills can be met by processing materials with typical levels
of organic content, without installing and operating add-on pollution
control systems that would be relatively costly. Feed materials that
have sufficiently low levels of organic matter are widespread across
the U.S., and the siting of new kilns is not expected to be
significantly limited by the proposed emission limit. Information is
not available to quantify the costs of excluding deposits of feed
materials with the highest levels of organic constituents as the
primary feed for new kilns. Owners/operators of the few existing cement
plants that process feed materials containing relatively high levels of
organic material, and who desire to expand production through the
addition of a new kiln, would need to blend their existing feed
materials with lower THC materials from offsite, or selectively process
lower organic portions of the feed materials from the onsite mine or
quarry in the new kiln. Regarding the costs of monitoring, for new NHW
kilns and in-line kiln/raw mills, the projected fifth-year national
capital and annual costs of monitoring THC with a continuous emission
monitor at an estimated four new kilns are $576,000 and $340,000,
respectively (docket item II-B-77).
H. Economic Impacts
An economic analysis of the proposed NESHAP was conducted. The EPA
estimates that regional market price increases would be between 0.6 and
2.0 percent. The national average price increase is estimated to be 1.1
percent. The related decreases in quantity demanded are estimated to
range from 0.5 to 1.8 percent, with a national average of 0.9 percent.
Domestic production is estimated to decrease more than consumption (1.7
percent compared to 0.9 percent nationally because imports are
estimated to increase by 6.3 percent). The decreases in domestic
production may lead to the loss of approximately 230 jobs. No plants
are expected to close; two kilns are expected to cease operating
(docket item II-A-46).
V. Selection of Proposed Standards
A. Selection of Source Category
Section 112(c) of the Act directs the Agency to list each category
of major and area sources, as appropriate, that emits one or more of
the HAPs listed in section 112(b) of the Act. The EPA published an
initial list of source categories on July 16, 1992 (57 FR 31576), and
revised the list on June 4, 1996 (61 FR 28197). ``Portland Cement
Manufacturing'' is one of the 174 categories of sources on the initial
list. As defined in the EPA report, ``Documentation for Developing the
Initial Source Category List'' (docket item II-A-18), the Portland
Cement Manufacturing source category includes any facility engaged in
manufacturing portland cement by either the wet or dry process. The
category as described for the listing includes but is not limited to
the following process facilities: kiln, clinker cooler, raw mill
system, finish mill system, raw material dryer, raw material storage,
clinker storage, finished product storage, conveyor transfer points,
bagging, and bulk loading and unloading systems.
The term ``major source'' is defined under section 112(a)(1) of the
Act and in the EPA general provisions (40 CFR 63.2) as:
* * * any stationary source or group of stationary sources
located within a contiguous area 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 * * *
This definition of major source has been upheld in a recent decision,
National Mining Ass'n v. EPA, 59 F.3d 1351 (D.C. Cir. 1995). In this
case, the Court also concluded that ``EPA may require the inclusion of
fugitive emissions in a site's aggregate emissions without conducting
any special rule making'' for the purpose of determining whether a
source is major.
The listing of the portland cement major source category was based
on the Administrator's determination that some portland cement plants
would be major sources of particulate HAPs, including but not limited
to compounds of arsenic, cadmium, chromium, lead, manganese, mercury,
nickel, and selenium. Information and data have been compiled by the
EPA characterizing the portland cement manufacturing process and its
associated emission sources. There are three main steps to
manufacturing portland cement: (1) kiln feed preparation (i.e.,
crushing and grinding), (2) firing the raw mix in a rotary kiln to
produce clinker (including fuel handling), and (3) clinker grinding to
produce cement. The responses received from the information collection
request (ICR) that was sent to every company in the industry indicated
that HAP emissions have been identified from all steps in the
manufacturing process. The kiln feed preparation and clinker grinding
operations all produce particulate emissions, a fraction of which are
metal HAPs. The responses also showed that HAPs are emitted from the
clinker production step; the kiln exhaust gases contain metal HAPs,
organic HAPs, and HCl.
All kiln exhaust gases are controlled at the existing plants by
either FFs or ESPs to limit PM emissions. Based on currently available
data, there are no plants that would be defined as major sources
according to section 112(a) of the Act on the basis of the mass of
metal HAPs emitted from kilns. That is, the reported emissions,
considering controls, did not exceed 9.1 Mg/yr (10 tpy) of a single
metal HAP or greater than 22.7 Mg/yr (25 tpy) of a combination of metal
HAPs from a cement kiln. However, operators of portland cement plants
must include HAP emissions from fugitive sources in determining whether
their facility is a major source of HAP emissions. Fugitive sources may
emit enough HAP metals to make a plant a major source (when fugitive
emissions are combined with all other HAP emissions at the site).
ICR responses for individual plants did show quantities of hydrogen
chloride (HCl) and chlorine each being emitted in excess of 9.1 Mg/yr
(10 tpy).
[[Page 14193]]
Most HCl emissions (reported in the ICR responses) were measured by EPA
Method 26, a method that may underestimate HCl emissions by a factor of
2 to 25 (docket item II-I-121). Results of Fourier Transform Infrared
(FTIR) spectroscopy emissions tests suggest that most plants may be
major sources of HCl. Hydrochloric acid concentrations of two wet
process portland cement kiln exhaust gases (docket item II-A-20, docket
item II-A-40) determined by FTIR spectroscopy ranged from 11 parts per
million by volume (ppmv) to 110 ppmv (dry basis corrected to 7 percent
oxygen). Assuming an average HCl emission of 50 ppmv (dry basis,
corrected to 7 percent oxygen), a wet kiln producing 600,000 tpy of
clinker would emit approximately 150 tpy of HCl.
Some plants reported formaldehyde, benzene, and toluene emissions
each to be in excess of 9.1 Mg/yr (10 tpy). One plant injects activated
carbon into the kiln exhaust to reduce the plume opacity thought to be
caused by hydrocarbons in the feed (docket item II-B-35). Various
organic HAPs were detected in its kiln exhaust using FTIR spectroscopy
(docket item II-A-41). Based on the kiln operating 330 d/yr, 24 hr/d,
kiln emissions were estimated at 331 Mg/yr (365 tpy) of hexane, 29 Mg/
yr (32 tpy) of benzene, 27 Mg/yr (30 tpy) of toluene, 15 Mg/yr (16 tpy)
of naphthalene, and 12 Mg/yr (13 tpy) chlorobenzene (docket item II-A-
41, docket item II-B-76).
Based on ICR responses, acetaldehyde, acrylonitrile, arsenic
compounds, lead compounds, manganese compounds, mercury compounds,
naphthalene, phosphorus, styrene, and xylenes were emitted at rates of
one tpy or greater from at least one portland cement kiln (docket item
II-B-69). The analysis of HAP emissions data from portland cement
manufacturing plants summarized above indicates that most if not all
cement plants are major sources of HAP emissions.
Consideration of subcategories or classes. Section 112(d)(1) of the
Act provides that the Administrator may distinguish among classes,
types and sizes of sources within a category or subcategory in
establishing standards. The EPA reviewed the listed source category to
determine if different classes were warranted. All portland cement is
manufactured in direct-fired, rotating kilns. In 1993, 210 kilns at 118
plants were in operation throughout the nation and Puerto Rico (docket
item II-I-101).
There are two main portland cement manufacturing processes
differentiated on the basis of feed preparation: wet process and dry
process. Approximately one-third of the kilns in operation use a wet
process; the other two-thirds use a dry process. The trend in the
industry for new kilns is toward the dry process because it is more
energy efficient than the wet process. Within the dry process there are
three variations: long kiln dry process, preheater process, and
preheater/precalciner process. The wet process kilns and all variations
of the dry process kilns use the same raw materials and use the same
types of pollution controls for PM emissions (docket item II-C-94,
attachment chapters 2 and 3). Based on ICR responses and test data the
use of these pollution controls to meet the NSPS for PM is feasible for
wet kilns and all types of dry kilns. Likewise test data show that
lowering kiln exhaust gas temperature to 400 deg. F at the APCD inlet,
MACT for reducing D/F concentrations, is feasible for wet and all types
of dry kilns. In any event, if classes were defined based on process
type, the MACT floor technology would be identical (docket item II-B-
73). For this reason, the EPA does not propose classes based on process
type.
The EPA OSW has recently proposed NESHAPs for various HWC types,
including cement kilns which burn hazardous waste.11 The
proposal is consistent with the terms of the 1993 settlement agreement
between the Agency and a number of groups that challenged EPA's final
RCRA rule entitled ``Burning of Hazardous Waste in Boilers and
Industrial Furnaces'' (56 FR 7134, February 21, 1991) and with the
Agency's Hazardous Waste Minimization and Combustion Strategy that was
first announced in May 1993. Hazardous waste burning cement kilns are
included in the portland cement manufacturing source category, but are
subject to different regulations than the NHW kilns. This proposed
NESHAP for portland cement manufacturing covers only NHW kilns and NHW
in-line kiln/raw mills. However, this proposed NESHAP does cover the
other affected sources (including clinker coolers, raw material dryers,
and materials handling processes) located at manufacturing plants
regardless of whether the plant has hazardous waste-burning cement
kilns.
---------------------------------------------------------------------------
\11\ The EPA proposed regulations for subpart EEE of 40 CFR part
63 on April 19, 1996 at 61 FR 17358.
---------------------------------------------------------------------------
Decision to regulate portland cement area sources. Section
112(c)(6) of the Act states that by November 15, 2000, EPA must list
and promulgate section 112(d)(2) or (d)(4) standards (i.e., standards
reflecting MACT) for categories (and subcategories) of sources emitting
seven specific pollutants, including the following HAPs emitted by
cement kilns: mercury, 2,3,7-8 tetrachlorodibenzofuran, and 2,3,7-8
tetrachlorodibenzo-p-dioxin. (Although other 112(c)(6) HAPs have been
found in cement kiln exhaust, the majority of the emissions data and
concern for NHW cement kiln 112(c)(6) HAPs is for mercury and dioxin/
furans.) The EPA must assure that source categories accounting for not
less than 90 percent of the aggregated emissions of each enumerated
pollutant are subject to MACT standards. Congress (docket item II-I-13,
p. 155 to 156) singled out the HAPs enumerated in section 112(c)(6) as
being of ``specific concern'' not just because of their toxicity but
because of their propensity to cause substantial harm to human health
and the environment via indirect exposure pathways (i.e., from the air
through other media, such as water, soil, food uptake, etc.).
Furthermore, these pollutants have exhibited special potential to
bioaccumulate, causing pervasive environmental harm in biota (and,
ultimately, human health risks).
The EPA estimates that approximately five tons of mercury are
emitted annually in aggregate from NHW cement kilns at portland cement
plants in the U.S. (docket item II-B-65). Also, it is estimated that
NHW kilns emit in aggregate approximately 22 lb of D/F (or about 0.10
lb TEQ per year (docket item II-B-57, docket item II-B-76). To assure
that these pollutants are subject to MACT, EPA is proposing to add the
portland cement manufacturing area source category to the list of
source categories and subcategories listed pursuant to section
112(c)(6). [See 62 FR 33625, 33637-38; June 20, 1997.] The EPA is doing
so because area and major source cement kilns emit these HAPs in
roughly equal quantities, because the dioxins and furans emitted by
area sources are equally toxic as those emitted by major sources (i.e.,
the distribution of dioxin and furan isomers is the same for both area
and major sources), and because these are particularly toxic HAPs. In
addition, EPA is already counting on control of these pollutants from
cement kiln area sources through the MACT process in assuring that
sources accounting for at least 90 percent of the emissions of these
HAPs are subject to standards under section 112(c)(6). [See 62 FR at
33635, 33636; June 20, 1997.]
The EPA notes, however, as it did in the June 20th notice, that
although the section 112(c)(6) listing process makes sources subject to
standards under subsection (d)(2) or (d)(4), the language of section
112(c)(6) does not specify
[[Page 14194]]
either a particular degree of emissions control or a reduction in these
specific pollutants emissions to be achieved by such regulations.
Rather, the specific control requirements will result from determining
the appropriate level of control under MACT [section 112(d)(2), or
section 112(d)(4)], and this interpretation will be made during the
section 112(d) rulemakings affecting the particular source category,
not as part of the section 112(c)(6) listing process. [See 62 FR at
33631; June 20, 1997.]
As noted above, EPA is interpreting section 112(c)(6) to require
the Agency to establish standards under section 112(d)(2) or 112(d)(4)
for all sources listed pursuant to section 112(c)(6), whether such
sources are major or area sources. This interpretation reflects the
express language of section 112(c)(6) that sources * * * of each such
pollutant are subject to standards under subsection (d)(2) or (d)(4)
and is in accord with the function of section 112(c)(6):
To assure that sources emitting significant amounts of the most
dangerous HAPs are subject to the rigorous MACT standard-setting
process.
[See S. Rep. No. 228, 101st Cong. 1st Sess., pp. 155, 166.]
The EPA has in fact already adopted this interpretation in the
proposed rule for hazardous waste combustion sources.
[See 61 FR at 17365; April 19, 1996.]
Under an alternative interpretation of section 112(c)(6), the
Agency might also establish standards pursuant to section 112(d)(5)--
based on generally available control technology (GACT)--for area
sources listed under section 112(c)(6). Section 112(d)(5) states that
for categories and subcategories of area sources listed pursuant to
subsection 112(c), the Administrator may establish standards pursuant
to GACT rather than MACT. Although the reference to listing area
sources may have been intended to refer to the area source listing
process in section 112(c)(3), it arguably extends to listing under
section 112(c)(6) as well. The Agency requests comment on the use of
this alternative approach to standard-setting for area sources listed
under section 112(c)(6).
In addition, the EPA is interpreting section 112(c)(6) to require
that, for sources listed under section 112(c)(6), MACT [or section
112(d)(4)] controls apply only to the section 112(c)(6) HAPs emitted by
the source. Thus, in this proposed rule, only mercury, D/F, and POM
(using THC as a surrogate) emitted by cement kiln area sources would be
subject to the MACT standards. The EPA is aware that it proposed a
different interpretation in the hazardous waste combustion NESHAP (see
61 FR at 17365-66), but now believes that section 112(c)(6) is better
read to apply only to particular HAPs rather than to the entire source.
(Since the language of section 112(c)(6) is ambiguous as to whether the
entire source must comply with MACT, or just for the HAPs enumerated in
section 112(c)(6), [see 61 FR at 17365 n. 12], either interpretation is
legally permissible.) Applying the provision to the entire source could
result in applying MACT to all HAPs emitted by area sources under
circumstances where control would not otherwise be warranted.
B. Selection of Emission Sources
The portland cement manufacturing process consists of the following
unit operations:
(1) Grinding the carefully proportioned raw materials to a high
degree of fineness;
(2) firing the raw mix in a rotary kiln to produce clinker;
(3) grinding the resulting clinker to a fine powder and mixing with
gypsum to produce cement; and
(4) raw and finished materials handling.
The following sections include descriptions of the affected sources
in the portland cement manufacturing source category, the origin of
emissions from these affected sources, and factors affecting the
emissions. The affected sources for which MACT standards are being
proposed include the kiln, in-line kiln/raw mills, clinker cooler, raw
and finish mills, raw material dryer, and materials handling processes.
1. Feed Preparation Processes (Grinding, Conveying)
Oxides of calcium, silicon, aluminum, and iron comprise the basic
ingredients of cement. The calcareous raw materials include limestone,
chalk, marl, sea shells, aragonite, and an impure limestone known in
the industry as natural cement rock. The requisite silica and alumina
may be derived from clay or shale from a limestone quarry. Such
materials usually contain some of the required iron oxide, but many
plants need to supplement the iron with mill scale, pyrite cinders, or
iron ore. Silica is supplemented, if necessary by adding sand to the
raw mix; alumina may be supplemented by adding bauxite or alumina-rich
flint clays to the raw mix (docket item II-I-5, p. 180).
Industrial by-products and wastes are becoming more widely used as
feed materials for cement production, e.g., slags contain carbonate-
free lime, as well as substantial levels of silica and alumina. Fly ash
from coal-fired boilers can often be a suitable feed component, since
it is already finely dispersed and provides silica and alumina (docket
item II-I-5, p. 180).
Ball mills are used to grind the feed material to the required
fineness for both the wet and dry processes. In the wet-kiln process,
the raw materials are ground with water to produce a well-homogenized
slurry. In the dry-kiln process, raw materials are ground in closed-
circuit ball mills with air separators.
Emissions from the grinding and conveying operations are
essentially particulate emissions (e.g., dust from limestone, clay,
bauxite ore) which contain HAP metals. Particulate matter control
devices (FFs and ESPs) serve as HAP control devices. The quantity of
emissions of HAP metals from raw materials handling processes are site
specific and depend on dust control practices and weather conditions.
2. Feed Preparation Processes (Drying, Blending, Storage)
Drying of kiln feed materials can be carried out in separate units
that are gas-or coal-fired. However, to improve the process energy
efficiency, waste heat can be utilized directly in the mill by routing
the kiln gases through the raw mill. The catch from the APCDs that
follow the raw mill is returned to the process and therefore, the APCD
is also part of the process (docket item II-I-109, chapter 11.6). Where
kiln gases are routed through the raw mill, emissions from the combined
in-line kiln/raw mills must be controlled for the same pollutants and
to the same extent as kiln gases.
The more energy efficient preheater and preheater/ precalciner
kilns usually route the exhaust gas from the preheater to a raw mill to
dry the material in suspension in the mill. The gas stream exits the
raw mill heavily laden with kiln raw material and is exhausted to an
APCD to recover the raw material and any material entrained from the
kiln preheater system. The raw material is collected and fed to a
blending system to provide the kiln with a homogenous raw feed. Dry
process blending is usually accomplished in a silo with compressed air
(docket item II-I-5, p. 183).
If the raw material dryer uses heat from a separate combustion
source (fuel-fired raw material dryer), exhaust gases may contain trace
quantities of products of incomplete combustion (PICs), HCl, and metals
from the fuel. In addition, if the feed materials contain organic
matter, this material may volatilize in the raw material dryer
(regardless of the
[[Page 14195]]
source of the heat) and the dryer exhaust may contain organic HAPs.
Under the NSPS, emissions from the raw material dryer and the feed
preparation materials handling processes (raw mill system, raw material
storage, and conveyor transfer points) are currently subject to a limit
of 10 percent opacity.
3. Kiln
The high temperature processing required to produce portland cement
takes place in the rotary kiln. The rotary kiln consists of a
refractory-brick-lined cylindrical steel shell that is rotated by an
electrical drive. It is a countercurrent heating device slightly
inclined so that material fed into the cooler, upper end travels slowly
by gravity to be discharged onto the clinker cooler from the hotter,
lower discharge end. The burners at the firing end, i.e., the lower or
discharge end, produce a current of hot gases that heats the clinker
and the calcined and raw materials in succession as the gases pass
toward the feed end. As has been mentioned, a kiln can be classified as
wet (in which the kiln feed is a slurry) or dry. Dry process kilns
include the older-style, long dry process kiln with a single firing
point; the preheater/kiln system; and the preheater/precalciner kiln
system. In the preheater/precalciner system, a second burner is used to
carry out calcination in a separate vessel interposed between the
preheater and the kiln. The precalciner uses preheated combustion air
drawn from the clinker cooler and the kiln exit gases and is equipped
with an oil or coal burner that burns 50 to 60 percent of the total
kiln fuel input. The precalciner system permits the use of smaller
kilns since only the actual clinkering process is carried out in the
rotary kiln.
The kiln exhaust contains a wide variety of HAPs and other air
pollutants that originate from the fuel combustion and from the feed
material. In 1991, about 87 percent of the total U.S. kiln capacity
used coal, coke, or a combination of coal and coke as the primary fuel
(docket item II-I-42, p. 20). Only 3.5 percent of the kiln capacity is
fired with natural gas alone (not in combination with other fuels) and
oil as a primary fuel represented an insignificant fraction of the
total kiln capacity. Plants firing waste-derived fuels account for the
balance of the total capacity. The most common waste fuels used in
cement kilns are RCRA hazardous waste, tires and tire-derived fuel. To
a lesser extent, MSW, medical waste, and used motor oil are fired.
Feed materials are a source of gaseous organic HAP emissions. Some
feed materials contain organic carbon such as petroleum or kerogens.
The organic carbon can volatilize in the kiln and appear at the stack
exit as a ``blue haze'' which may contain organic HAPs. During one EPA-
sponsored test at a cement kiln using feed material with a high organic
matter content, significant levels of benzene (32 tpy) were detected in
the kiln exhaust (docket item II-A-41, docket item II-B-76). Organic
HAP emissions were found to vary with THC emissions during this test.
Chlorine entering the kiln system (from raw materials and also from
fuels) may react with the organic compounds present in the raw
materials or with PICs, to form chlorinated hydrocarbons or D/F in the
kiln stack exhaust. Approximately 20 percent of the HAPs listed in
section 112 of the Act are chlorinated organic compounds.
In the wet process and in the long kiln dry process, the emission
point for the kiln gases is typically the APCD discharge stack. In the
more complex preheater and precalciner process designs, the kiln gases
are routed through other pieces of process equipment, such as the raw
mill. In-line kiln/raw mills vent kiln gases through the raw mill. In
these systems the gases discharged from the APCD on the raw mill, are
in fact kiln exhaust gases.
The kiln alkali bypass stack is an additional emission point for
kiln gases which is sometimes found with preheater and precalciner
processes. The alkali bypass gas streams are kiln gases that have not
contacted the incoming feed material. The kiln gases that are drawn out
of the kiln prior to contact with the precalciner and preheater
sections pass through a separate APCD and may be discharged to the
atmosphere through a separate stack. In other process arrangements, the
treated alkali bypass gases are combined with the main kiln exhaust
gases and are discharged through a common stack. It is expected that
the same HAPs found in the main kiln stack are found in the alkali
bypass stack.
Kiln PM/HAP metals. All HAP metals have been identified in kiln
exhaust PM at various levels. Based on analysis of emissions test
reports, the total average HAP metal content of kiln exhaust PM is
approximately one weight percent (docket item II-B-36). Mass emission
rates of metal HAPs from the kiln depend on the concentration of metals
in the PM and the emission rates of PM. Analyses of emissions data
(docket item II-B-62) have shown that ESP-controlled PM emissions for
six NHW kilns ranged from 0.009 to 0.20 gr/dscf (corrected to seven
percent oxygen), with an average of 0.045 gr/dscf for 14 data points.
Fabric filter-controlled PM emissions for five NHW kilns ranged from
0.002 to 0.29 gr/dscf (corrected to seven percent oxygen), with an
average of 0.014 gr/dscf for 10 data points. For a 600,000 ton of
clinker/year kiln (this represents the capacity of a mid-sized kiln),
the range of kiln PM emissions (0.002 gr/dscf to 0.29 gr/dscf)
corresponds to 9 tpy to 1,360 tpy (docket item II-B-76). Based on an
average kiln PM emission of 0.03 gr/dscf, and assuming HAP metal
emissions are one percent by weight of PM emissions, HAP metal
emissions are approximately 1.4 tpy for a 600,000 ton of clinker/year
kiln (docket item II-B-76). Based on ICR responses, at least one plant
reported kiln emissions of over one tpy for one or more of the
following metal HAPs: chromium, lead, arsenic, mercury, antimony, and
manganese. However, no plant reported kiln emissions of more than 10
tpy of any single metal HAP (docket item II-B-69).
Kiln mercury. Mercury may be emitted in the kiln exhaust as either
a particulate or a gas. A summary was compiled of all currently
available mercury emission data for HW and NHW kilns (docket item II-B-
65). There are 8 data points for 7 NHW kilns, and 19 data points from
21 HW kilns (two sets of kilns shared a stack). The HW kiln data were
adjusted to remove mercury in the HW fuel and any mercury spikes. By
removing the portion of emissions attributed to test method spiking and
HW fuel mercury inputs, corrected emission data that are comparable
with data from NHW kilns were developed.
For a 600,000 ton of clinker/year kiln, the range of the mercury
emissions data [0.6 to 83 micrograms (g)/dscm at 7 percent
oxygen] corresponds to 0.0012 tpy to 0.17 tpy (docket item II-B-76),
while the average mercury emission (24 g/dscm) corresponds to
approximately 0.05 tpy (docket item II-B-76). One plant responding to
the ICR reported mercury emissions of over one ton per year.
Kiln D/F. For the purposes of analysis of the data, concentrations
of dioxin and furan congeners (specifically the tetra, hepta, hexa, and
octa congeners) were converted to a concentration that was equivalent
to the toxicity of 2,3,7,8-tetrachlorodibenzo-p-dioxin. Determination
of TEQ concentrations was performed according to the international
method (docket item II-A-8).
An analysis of all available D/F emission data from 15 NHW kilns
showed that concentrations of D/F TEQ emitted in the kiln exhaust gas
measured downstream of the PMCD
[[Page 14196]]
ranged from 0.001 ng TEQ/dscm to over 1.2 TEQ ng/dscm with an average
of 0.20 ng TEQ/dscm (all concentrations at 7 percent oxygen)[D/F test
data are shown in Table 8 in Section V.D.2]. For a 600,000 ton of
clinker/year kiln, the range of the D/F TEQ concentrations (0.001 to
1.2 ng/dscm) corresponds to 0.0018 g/yr to 2.2 g/yr (docket item II-B-
76), while the average concentration (0.20 ng TEQ/dscm) corresponds to
an emission of 0.4 g TEQ/year (docket item II-B-76).
The predominant factor affecting D/F emissions is the temperature
of gases at the inlet to the PMCD (docket item II-I-81, docket item II-
I-82). Test data collected from both HW and NHW kilns show a trend of
decreasing D/F gas stream concentrations with decreasing temperature at
the inlet to the PMCD. In tests conducted on individual cement kilns
where the gas stream temperature was varied in the range of 350 to
500 deg.F, reductions in D/F TEQ concentrations by factors of 5 to 10
were observed when gas temperatures entering the PMCD were lowered from
the upper to lower end of the temperature range (docket item II-I-81,
docket item II-I-82).
Kiln THC/organic HAPs. The THC and organic HAP concentrations and
emission levels from kilns vary widely, depending primarily on the feed
materials (docket item II-I-66, docket item II-I-67, docket item II-I-
68). Some feed materials contain organic carbon such as petroleum or
kerogens. One kiln operator has conducted an extensive study of the
source of high THC and carbon monoxide (CO) emissions from the kiln
(docket item II-I-107). Higher than normal emissions from this kiln
were attributed to the shale used in the raw materials. Replacing the
shale with fire clay in the raw mix resulted in a dramatic reduction of
THC and CO emissions.
Another NHW kiln operator has determined that the raw materials are
the source of the majority of the observed benzene emissions (docket
item II-D-112). Kiln stack gas and preheater gas stream analyses before
and after switching fuel from a combination of coal and petroleum coke
to 100 percent natural gas showed little effect on benzene emissions.
These test data suggest that benzene emissions derived from the raw
materials (docket item II-I-41).
Fourier transform infrared spectroscopy was used to determine
organic HAP emissions at a NHW kiln. Estimated organic HAP emissions
(based on average concentrations measured in the kiln exhaust and 7,920
hr/yr of operation) showed that the kiln was a major source based on
organic HAP emissions. Organic HAP emission rates were estimated at 331
Mg/yr (365 tpy) hexane, 27 Mg/yr (30 tpy) toluene, 29 Mg/yr (32 tpy)
benzene, 14.5 Mg/yr (16 tpy) naphthalene, and 12 Mg/yr (13.2 tpy)
chlorobenzene (docket item II-A-41, docket item II-B-76).
In the ICR responses, many organic HAPs were reported as being
emitted in the kiln exhaust gas. Organic HAPs for which there was at
least one report of emissions of at least 0.91 Mg/yr (1.0 tpy) include
benzene, naphthalene, toluene, formaldehyde, xylenes, styrene, and
acetaldehyde. One facility reported more than 9.1 Mg/yr (10 tpy) each
of benzene and toluene emissions (docket item II-B-69).
Stack concentrations of THC were available for 16 NHW kilns (docket
item II-B-75). The concentrations were expressed in ppmv as propane on
a dry basis (ppmvd) at seven percent oxygen. For a 600,000 ton of
clinker/year kiln, the range of kiln THC emissions (0.4 ppmvd to 224
ppmvd as propane) corresponds to 1.5 tpy to 840 tpy (docket item II-B-
76), while the average kiln THC emissions (35 ppmvd as propane)
corresponds to 131 tpy (docket item II-B-76). Organic HAP
concentrations, as a percentage of THC for these data, ranged from 0 to
98 percent (docket item II-B-75). With an average of 23 percent of the
THC emissions being organic HAPs a 600,000 ton of clinker/year kiln
would emit from 0.3 tpy to 190 tpy of organic HAPs, based on the range
of THC stack concentrations.
The emissions from kiln alkali bypasses are expected to be the
result of incomplete combustion of fuel in the kiln, since this exhaust
gas stream does not contact incoming kiln feed materials. Alkali bypass
concentrations of THC were available for two kilns operating under NHW
conditions. The concentrations were expressed as ppmvd (as propane) at
seven percent oxygen, and averaged 3.4 ppmvd and 27 ppmvd, respectively
(docket item II-B-75). For typical alkali bypass gas flow rates at a
600,000 ton of clinker/year kiln, this range corresponds to
approximately 2.4 tpy to 19 tpy of THC, while the average kiln bypass
THC concentration (15 ppmvd) corresponds to 10.5 tpy of THC (docket
item II-B-76). Assuming that 5 percent of the THC emissions from alkali
bypasses are organic HAPs (docket item II-B-75), a 600,000 ton of
clinker/year kiln would emit from 0.3 tpy to 6 tpy of organic HAPs,
based on the range of THC alkali bypass stack concentrations.
Kiln HCl. The currently available HCl emission data obtained from a
total of 46 NHW and HW kilns range from 0.2 ppmvd to 157 ppmvd and the
average is 27 ppmvd for 72 data points (docket item II-B-62). (All
concentrations were corrected to seven percent oxygen.) For a 600,000
ton of clinker/year kiln, the range of kiln HCl emissions corresponds
to 0.6 tpy to 490 tpy, while the average HCl emission (27 ppmvd)
corresponds to 84 tpy (docket item II-B-76). Based on analyses of test
reports and ICR responses, HCl emissions range from less than 0.91 Mg/
yr (1 tpy) to over 272 Mg/yr (300 tpy). Ten plants responding to the
ICR reported emissions of HCl greater than 9.1 Mg/yr (10 tpy) from each
of 15 different kilns (docket item II-B-69).
The EPA notes that with the exception of three kilns that were
measured by FTIR, all of the HCl emission measurements included in the
analysis were obtained using EPA Method 26. A recently completed study
that compared the results of a draft test protocol using the gas filter
correlation infrared (GFCIR) instrumental method (proposed EPA Method
322) and EPA Method 26 found that HCl measured by GFCIR was typically
much higher than that measured by Method 26 (docket item II-I-121).
Concentrations of HCl measured by GFCIR ranged from 1.5 to 4.5 times
the concentrations measured by Method 26 for wet kilns and up to 30
times the concentrations measured by Method 26 for a dry kiln.
Subsequent laboratory recovery efficiency analyses suggested that
Method 26 is biased significantly low due to a scrubbing effect in the
front half of the sampling train. Therefore, it is likely that
currently available HCl emission data are understated.
4. Clinker Cooler
It is desirable to cool the clinker rapidly as it leaves the
burning zone of the kiln. Heat recovery, preheating of kiln combustion
air, and fast clinker cooling are achieved by clinker coolers of the
traveling-grate, planetary, rotary, or shaft type. Most commonly used
are grate coolers where the clinker is conveyed along the grate and
subjected to cooling by ambient air, which passes through the clinker
bed in cross-current heat exchange.
A portion of the clinker cooler exhaust serves as secondary
combustion air in the kiln. The remainder of the clinker cooler exhaust
is discharged to the atmosphere separately from the kiln exhaust gas
through a PM emission control device. Clinker cooler gases are also
sometimes routed through other pieces of process equipment, such as the
coal or raw mill, as a source of warm,
[[Page 14197]]
dry air prior to being reused as combustion air.
Since clinker coolers are not combustion devices, the only HAP
expected to be emitted are the metal HAPs associated with the clinker
cooler particulate, i.e., clinker dust. HAP metals that have been
detected in clinker include chromium, lead, nickel, arsenic, beryllium,
antimony, selenium, and mercury. In one study conducted by the Portland
Cement Association (docket item II-I-44, p. 4), the average
concentration of metal HAPs that has been detected in clinker is 555
parts per million by weight (ppmw). In an earlier study, cited by EPA
OSW the average HAP metal content in clinker was found to be 138 ppmw
(docket item II-A-24, pp. 3-62 to 3-65). Under the existing NSPS,
emissions of PM from clinker cooler gases are limited to 0.05 kg/Mg
feed (dry basis) (0.10 lb/ton). A plant producing 600,000 tpy of
clinker, emitting PM from the clinker cooler at the NSPS limit, would
emit 6 kg (14 lb) of HAP metals per year, assuming a 140 ppmw HAP metal
content in the PM (docket item II-B-76).
5. Finish Grinding/Conversion of Clinker to Portland Cement
The cooled clinker is conveyed to clinker storage or mixed with
gypsum and introduced directly into the finish mills. The finish mills
are large, rotating steel cylinders containing a charge of steel balls.
The clinker and gypsum are ground to a fine, homogeneous powder. Two
different types of mill systems may be used. In open-circuit milling,
the material passes directly through the mill without any separation of
fine and coarse particles. In closed-circuit grinding, the mill product
is carried to a cyclonic air separator in which the coarse particles
are rejected from the product and returned to the mill for further
grinding.
The finished portland cement is conveyed to bulk storage silos from
which it is dispensed for shipping. Portland cement is often loaded in
bulk into hopper trucks or rail cars. It may also be packaged in ``tote
bins'' or in 80 lb or 94 lb kraft paper bags. The bags are loaded onto
pallets for handling, warehousing, and shipping.
The only HAPs expected to be emitted from clinker/cement handling
processes are the metal HAPs associated with clinker and cement dust.
As was noted above, clinker dust is estimated to contain 555 ppmw of
metal HAPs. The HAP metals that have been identified in portland cement
include chromium, nickel, arsenic, lead, antimony, selenium, beryllium,
cadmium, and mercury. In cement (as opposed to clinker), the
concentrations of individual HAP metals range from an average of 0.014
ppmw mercury to an average of 76 ppmw chromium. The total average
concentration of metal HAPs in portland cement is 143 ppmw (docket item
II-I-44).
Total nationwide emissions of HAPs, PM, and VOCs from the above
emission sources in portland cement plants are estimated at 23,300 Mg/
yr (25,700 tpy). Over 260 Mg/yr (290 tpy) of these emissions are HAPs.
Emissions of PM and VOCs are estimated at 23,000 Mg/yr (25,400 tpy).
Given that these processes release significant quantities of HAPs
and the availability of emission control systems, the Agency selected
to develop and propose NESHAP for the following emission sources: NHW
kilns and NHW in-line kiln/raw mills; NHW kiln alkali bypasses; clinker
coolers; raw material dryers; feed preparation and materials handling
processes including raw mills, finish mills, storage bins (raw
material, clinker, finished product), conveying system transfer points,
bagging system, and bulk loading and unloading systems. Additional
information on the operations in portland cement plants selected for
regulation, and other operations, is included in the docket.
C. Selection of Pollutants
The proposed standards would limit emissions of metal HAPs [almost
all metals appearing in section 112(b) have been detected in portland
cement plant emissions] and organic HAPs (including D/F) from portland
cement manufacturing facilities. (Pollutant health effects were
discussed in section II.C.) These HAPs are emitted in significant
quantities from portland cement plant sources. The standards being
proposed to address metal and organic HAP emissions establish limits
for surrogate pollutants rather than for individual HAP compounds (a
separate emission limit is established for D/F). The reasons for using
surrogate pollutants are discussed below.
Controlling PM emissions will control the emissions of non-volatile
metal HAPs (and also the condensed organic HAPs including D/F which are
adsorbed on particulates). The available technologies used in the
cement manufacturing industry for the control of non-volatile HAP
metals are the same technologies (FFs and ESPs) as the proposed MACT
floor technologies for control of PM. Metal HAPs are estimated to
constitute about 1 percent by weight of kiln PM emissions from portland
cement manufacturing and about 0.06 percent by weight of clinker cooler
PM emissions. In addition, the use of PM as a surrogate for non-
volatile metal HAP emissions reduces the costs associated with
compliance testing and monitoring.
The proposed standards establish an emission limit for THC as a
surrogate for organic HAPs from new or reconstructed NHW kilns for the
following reasons. Methods used in the cement manufacturing industry
for the control of organic HAP emissions would be the same methods used
to control THC emissions. These emission control methods include using
feed materials with relatively low levels of organic matter and
achieving good combustion (docket item II-B-47, docket item II-B-48).
Standards limiting emissions of THC will also result in decreases in
organic HAP emissions (with the additional benefit of decreasing VOC
emissions).
Establishing emission limits for specific organic HAPs (with the
exception of D/F) would be impractical and costly. Total hydrocarbon,
which is less expensive to test for and monitor, can be used as a
surrogate for organic HAPs. Based on available data, organic HAPs range
from 0 to 98 percent of THC and are estimated to account for
approximately 23 percent on average of THC emissions from portland
cement manufacturing (docket item II-B-75). The Agency recognizes that
the level and distribution of organic HAPs associated with THC
emissions from cement kilns will vary from kiln to kiln. Limiting THC
as a surrogate for organic HAPs will eliminate costs associated with
speciating numerous compounds.
The proposed standards establish separate emission limits for D/F
because of the high toxicity associated with even low masses of these
compounds. In addition, data available to EPA establish the existence
of a separate MACT floor technology for D/F control.
The proposed regulation does not establish a limit for HCl
emissions from cement kilns because no MACT floor technology has been
identified. An HCl emission limit based on a beyond-the-floor control
option was determined not to be justified as discussed in section V.D.2
of this document.
The proposed regulation does not establish limits for mercury
emissions from cement kilns because no MACT floor control technology
has been identified. A mercury emission limit based on a beyond-the-
floor control option was determined not to be justified as discussed in
section V.D.2.
[[Page 14198]]
D. Selection of Proposed Standards for Existing and New Sources
1. Background
After the EPA has identified the specific source categories or
subcategories of sources to regulate under section 112, it must develop
MACT standards for each category or subcategory. Section 112
establishes a minimum baseline or ``floor'' for standards. For new
sources, the standards for a source category or subcategory cannot be
less stringent than the emission control that is achieved in practice
by the best-controlled similar source. [See section 112(d)(3)]. The
standards for existing sources may 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 for categories and subcategories with 30 or more
sources, or the average of the best-performing 5 sources for categories
or subcategories with fewer than 30 sources.
After the floor has been determined for a new or existing source in
a source category or subcategory, the Administrator must set MACT
standards that are technically achievable and no less stringent than
the floor. Such standards must then be met by all sources within the
category or subcategory. The regulatory alternatives selected for new
and existing sources may be different because of different MACT floors,
and separate emission limits may be established for new and existing
sources.
The EPA also may consider an alternative ``beyond the floor.''
Here, EPA considers the achievable reductions in emissions of HAPs (and
possibly other pollutants that are co-controlled), cost and economic
impacts, energy impacts, and other nonair environmental impacts. The
objective is to achieve the maximum degree of emission reduction
without unreasonable economic, energy or secondary environmental
impacts.
2. MACT Floor Technology, Emission Limits, and Format
The EPA conducted separate MACT determinations for PM (the
surrogate for HAP metals), D/F, mercury, THC (the surrogate for organic
HAPs), and HCl emissions from kilns and inline kiln/raw mills; for PM
emissions from clinker coolers; for PM and THC emissions from raw
material dryers; and for PM emissions from materials handling
facilities. For each combination of pollutant and affected source, MACT
floor technologies and beyond-the-floor control options were evaluated.
Several formats are available for establishing the emission limits
based on MACT. These include mass concentration (mass per unit volume),
volume concentration (volume per unit volume), mass emission rate (mass
per unit time), process emission rate (mass per unit of production or
other process parameter), and percent reduction.
For the portland cement manufacturing source category, EPA is
proposing numerical emission standards expressed as a process emission
rate and opacity limits for PM emissions from kilns; as mass per volume
of exhaust gas for D/F emissions from kilns; as volume per volume of
exhaust gas for THC emissions from kilns and raw material dryers; as a
process emission rate and opacity limit for clinker cooler PM
emissions; and as an opacity limit for materials handling facilities PM
emissions.
The following sections present a discussion of the rationale for
selecting the MACT technologies, emission limits, and format of the
standard for each affected source and associated pollutant.
Kiln and in-line kiln/raw mill PM HAP emissions. Well-designed and
properly operated FFs or ESPs are the PM control technologies presently
in use by the best performing 12 percent of existing kilns and in-line
kiln/raw mills. In the portland cement manufacturing industry, it is
estimated that at least 30 percent (docket item II-A-4) of existing
kilns are subject to the requirements of the NSPS for cement plants (40
CFR part 60, subpart F).
Table 7 lists the type of control device used with, and available
PM emissions data from, kilns and in-line kiln/raw mills subject to the
NSPS. The emission levels shown in Table 7 all meet the NSPS emission
limit and were all achieved with FFs and ESPs designed to meet the
NSPS. This represents the MACT floor technology for control of PM from
kilns and in-line kiln/raw mills.
Table 7.--Particulate Emissions From NSPS Kilns
[Docket Item II-A-4, Docket Item II-A-43, Docket Item II-B-62]
----------------------------------------------------------------------------------------------------------------
PM (kg/Mg dry
Kiln type APCD type feed) Location
----------------------------------------------------------------------------------------------------------------
PH................................. FF 0.0011 Southdown--Kosmosdale,
KY.
PC................................. FF a 0.0039 Boxcrow Cement--
Midlothian, TX.
PH................................. ESP b 0.0075 Ash Grove--Durkee, OR.
DRY................................ FF a 0.0090 Southdown #1--
Fairborn, OH.
PC................................. ESP c 0.015 RMC Lone Star--
Davenport, CA.
PC................................. FF 0.015 Kaiser Cement--
Cupertino, CA.
PH................................. ESP 0.015 Roanoke Cement--
Cloverdale, VA.
PC................................. FF 0.020 Moore McCormack--
Knoxville, TN.
PH................................. FF 0.029 Moore McCormack--
Brooksville, FL.
PC................................. FF 0.033 Kaiser Cement--Lucerne
Valley, CA.
PC................................. FF 0.035 Calif Portland--
Mojave, CA.
PC................................. FF 0.04 Martin Marietta--
Leamington, UT.
PC................................. ESP 0.044 Kaiser--San Antonio,
TX.
PC................................. FF 0.048 Martin Marietta--
Lyons, CO.
PH/PC.............................. ESP b 0.051 Lone Star--Cape
Girardeau, MO.
WET................................ ESP 0.056 Monolith Portland--
Laramie, WY.
DRY................................ FF 0.056 Lone Star--Pryor, OK.
DRY................................ ESP d 0.058 Ash Grove #2--
Louisville, NE.
PC................................. ESP 0.065 General Portland--New
Braunfels, TX.
PC................................. FF 0.068 Davenport Industries--
Buffalo, IA.
PH................................. FF 0.070 Ideal Basic--La Porte,
CO.
PH................................. FF 0.074 Southwestern Portland--
Odessa, TX.
DRY................................ ESP 0.11 Ash Grove #1--
Louisville, NE.
[[Page 14199]]
PC................................. ESP 0.12 Texas Industries--
Hunter, TX.
PC................................. ESP 0.13 Lehigh--Mason City,
IA.
WET................................ ESP 0.15 Genstar--San Andreas,
CA.
WET................................ FF 0.15 Lone Star--Salt Lake
City, UT.
----------------------------------------------------------------------------------------------------------------
PC = precalciner.
PH = preheater.
a = average of four tests.
b = average of three tests.
c = average of two tests.
d = average of five tests.
The data in Table 7 were obtained from EPA Method 5 compliance
tests on new kilns subject to the NSPS [0.15 kg/Mg dry feed (0.30 lb/
ton dry feed)]. These tests measure the performance of PM APCDs
associated with new kilns over a relatively short period (typically
three 1-hour test runs). These data show that PM emissions from ESPs
and FFs designed to meet the NSPS and operated and maintained to
demonstrate initial compliance with the NSPS under Method 5 test
conditions varied within a range of 0.0011 kg/Mg dry feed (0.0022 lb/
ton dry feed) to 0.15 kg/Mg dry feed (0.3 lb/ton dry feed). The data in
Table 7 show equivalent performance can be expected from FFs and ESPs,
and that neither technology offers a clear advantage. Due to the fact
that the best performing kilns and in-line kiln/raw mills use FFs and
ESPs designed to meet the NSPS and because of the variability in
performance of well-designed, well-maintained and properly operated FFs
and ESPs, the emission limit represented by the MACT floor technology
is equivalent to the NSPS of 0.15 kg/Mg dry feed (0.30 lb/ton dry
feed).
No technologies were identified for existing or new kilns or in-
line kilns/raw mills that would consistently achieve lower emission
levels of PM than the NSPS limit. Consequently, there is no beyond-the-
floor technology that has been shown to consistently achieve lower
emissions. Therefore the PM emission limit proposed for new and
existing kilns and in-line kiln/raw mills is 0.15 kg/Mg dry feed (0.30
lb/ton dry feed), which is equivalent to the NSPS limit.
The NSPS establishes an opacity limit, and an opacity limit is also
being proposed under this standard. The maximum 6-minute average
opacity level may not exceed 20 percent opacity, as is the case for the
NSPS.
The production-based emission limit format was chosen for kiln and
in-line kiln/raw mill PM emissions. The units for this emission
standard are kg of PM per Mg of dry feed (lb PM per ton of dry feed).
This format (mass per unit of production) and associated opacity limit
are consistent with the format of the portland cement plant NSPS (40
CFR part 60, subpart F). At least 30 percent of the kilns in the
industry are subject to the NSPS (docket item II-A-4) and these plants
are already monitoring the production-based emission rate and the
opacity.
A concentration format (e.g., g/dscm [gr/dscf]) was considered for
the kiln and in-line kiln/raw mill PM emission limit. One reason that
this format was not chosen was that it would be inconsistent with the
NSPS PM emission limit format. However, there are other considerations.
A concentration format would penalize more energy efficient kilns,
which burn less fuel and produce less kiln exhaust gas per megagram of
dry feed. This is because with a concentration based standard the more
energy-efficient kilns would be restricted to a lower level of PM
emitted per unit of production.
Kiln and in-line kiln/raw mill D/F emissions. The EPA has
identified two technologies for control of D/F emissions. One
technology achieves low D/F emissions by a combination of proper kiln
operation, proper combustion, proper control device operation, and a
reduction in the kiln gas temperature at the inlet to the PMCD. The
other technology is activated carbon injected into the kiln exhaust
gas.
The discussion in this section refers to D/F emissions in units of
TEQ. Toxic equivalent refers to the international method of expressing
toxicity equivalents for dioxins and furans as defined in EPA report,
``Interim Procedures for Estimating Risks Associated with Exposures to
Mixtures of Chlorinated Dibenzo-p-dioxins and -dibenzofurans (CDDs and
CDFs) and 1989 Update'' (docket item II-A-8).
Dioxin/furan emissions data were obtained from testing that was
conducted at NHW kilns, with NHW fuels at kilns that normally burn HW,
and under worst-case conditions at kilns that burn HW (as part of
Certificate of Compliance [COC] testing). Based on the test results for
both NHW and HW kilns, the predominant factor affecting D/F emissions
is the temperature of gases at the inlet to the PMCD (docket item II-A-
42; docket item II-B-78; docket item II-I-81, pp. 127 to 133; docket
item II-I-82, pp. 135 to 175). The highest D/F emissions (near 40 ng
TEQ/dscm) occurred at the highest gas temperatures (between 500 deg.F
and 700 deg.F) while the lowest emissions (near 0.02 ng TEQ/dscm)
occurred at the lowest temperature (at approximately 210 deg.F). [The
emission 0.02 ng TEQ/dscm is the average of the four NHW D/F test
results that were measured at gas temperatures less than 230 deg.F, as
shown in Table 8.]
Dioxin/furan TEQ emissions data and stack temperatures from kilns
firing NHW fuels are listed in Table 8. The data are listed in order of
ascending stack temperature. Fourteen NHW data points were obtained
during normal kiln operation, three points were obtained as NHW
baseline runs prior to HW COC testing, one data point (at the 518
deg.F stack temperature) was obtained at maximum combustion
temperature, and one point was obtained under unknown test conditions.
Stack temperatures are presented, since inlet PMCD temperature data are
not typically recorded during stack emissions testing. It is
acknowledged that stack temperatures will be lower than inlet PMCD
temperatures.
[[Page 14200]]
Table 8.--Average Dioxin/Furan Toxic Equivalent Emissions (at 7 Percent Oxygen) and Average Stack Gas Temperatures for NHW Cement Kilns and Kilns Tested
Under NHW Conditions
[Docket Item II-B-78]
--------------------------------------------------------------------------------------------------------------------------------------------------------
Avg TEQ ng/
Kiln type APCD type Kiln fuel Avg Gas T ( deg.F) dscm Kiln location
--------------------------------------------------------------------------------------------------------------------------------------------------------
PH/PC...................... FF Natural gas; main stack 183 0.011 Capital Aggregates--San
tested. Antonio TX.
PC......................... FF Coal,tires, pulp/paper mill 220 0.0063 Calaveras Cement--Redding
sludge. CA.
PH/PC...................... FF Natural gas; raw mill on... 221 0.042 Ash Grove--Seattle WA (kiln/
in-line mill).
PH/PC...................... ESP Not reported............... 226 0.00087 RMC Lonestar--Davenport CA.
PC......................... FF Coal & tires............... 233 0.21 Calaveras Cement--Redding,
CA.
PH/PC...................... FF Natural gas; bypass stack 299 0.054 Capital Aggregates--San
tested. Antonio TX.
WET........................ ESP Coal....................... 305 0.0024 Holnam--Florence CO.
WET........................ ESP Coal & natural gas......... 315 0.072 Ash Grove--Montana City MT.
WET........................ ESP Coal....................... 346 q 0.37 Lehigh--Union Bridge MD.
WET........................ ESP coal & tires............... 358 q 1.2 Lehigh--Union Bridge MD.
WET........................ ESP Coal/coke.................. 366 0.032 Holnam kiln #1--Holly Hill
SC.
DRY........................ FF Coal, gas, tire derived 396 0.0035 Riverside--Oro Grande CA.
fuel.
WET........................ ESP Natural gas................ 397 0.020 Capital Aggregates--San
Antonio TX.
DRY........................ FF Coal & natural gas......... 403 0.0084 Riverside--Oro Grande CA.
WET........................ ESP Coal....................... 417 0.12 Lone Star--Greencastle IN.
WET........................ ESP Coal/coke.................. 418 0.04 Holnam kiln #2--Holly Hill
SC.
DRY........................ ESP Coal, coke, & tires........ 450 0.074 Lone Star--Oglesby IL.
WET........................ ESP Coal....................... 482 0.55 Continental Cement--
Hannibal MO.
WET........................ ESP Coal....................... 518 1.0 Holnam--Clarksville MO.
--------------------------------------------------------------------------------------------------------------------------------------------------------
Abbreviations:
PH/PC = preheater/precalciner.
ESP = electrostatic precipitator.
PC = precalciner.
FF = fabric filter.
Note: Entries flagged with and q are listed in Table 9 and discussed in the text.
The data in Table 8 show that all NHW D/F emissions were less than
0.2 ng TEQ/dscm at stack temperatures below 340 deg.F, except for one
data point which is discussed below. The stack temperature of 340
deg.F corresponds to an estimated inlet PMCD temperature of
approximately 400 deg.F after accounting for cooling in the ductwork.
The EPA estimates that approximately 50 percent of existing PMCDs used
at both wet-and dry-type NHW kilns operate with a maximum inlet PMCD
temperature of approximately 400 deg.F (docket item II-B-73). Since
the MACT floor is based on the technology in use by the best performing
12 percent of the affected sources, the MACT floor for existing kilns
corresponds to reduction of kiln exhaust gas stream temperature at the
PMCD inlet to 400 deg.F.
One demonstrated method of temperature reduction is injection of
water to provide rapid cooling of kiln exhaust gases upstream of the
inlet to the PMCD. Rapid cooling reduces D/F formation that occurs
within the temperature window 232 deg.C (450 deg.F) to 343 deg.C
(650 deg.F).
As shown in Table 8, D/F emissions from 3 of the 13 tests conducted
at stack temperatures below 400 deg.F exceeded 0.2 ng TEQ/dscm. For
discussion purposes, the three data points are listed in Table 9 with
the corresponding stack temperature. The Calaveras kiln that emitted
0.21 ng TEQ/dscm when tested at a stack temperature of 233 deg.F
emitted 97 percent less D/F at a slightly lower stack temperature and
with a different mixture of fuels, demonstrating that the kiln could
achieve 0.2 ng/dscm through proper kiln combustion.
Table 9.--Data from KILNS at Which Dioxin/Furan TEQ Emissions Exceeded
0.2 ng/dscm
------------------------------------------------------------------------
Average
D/F TEQ
Average stack gas temperature (*F) (ng/dscm Kiln location
at 7%
O2)
------------------------------------------------------------------------
233.................................. 0.21 Calaveras--Redding CA.
346.................................. 0.37 Lehigh--Union Bridge
MD.
358.................................. 1.2 Lehigh--Union Bridge
MD.
------------------------------------------------------------------------
The Lehigh kiln emitted 0.37 ng TEQ/dscm at a stack temperature of
346 deg.F during coal combustion and 1.2 ng TEQ/dscm at a stack
temperature of 358 deg.F during coal and tire combustion. The EPA
concluded that the high emission (of 1.2 ng TEQ/dscm) resulted from
poorly controlled tire combustion/kiln operation, since (as shown in
Table 8) three other NHW kilns emitted less than 0.2 ng TEQ/dscm when
tested while burning tires. In the absence of detailed information on
kiln and APCD operating conditions, fuel firing and combustion control,
the Lehigh emission level of 0.37 ng TEQ/dscm at a stack temperature of
346 deg.F cannot be explained.
Temperature reduction to 400 deg.F, in conjunction with proper
control of kiln and PMCD operation and efficient combustion will limit
D/F emissions to 0.2 ng TEQ/dscm in most (if not all) cases, and the
proposed D/F standard for existing kilns is set at this level. The EPA
recognizes that the available emissions data show that one kiln (as
illustrated by the Lehigh data in Table 9) cannot achieve 0.2 ng TEQ/
dscm at an inlet temperature to the PMCD below 400 deg.F, and that
parameters consistent with proper equipment operation have not been
precisely specified. The proposed standards therefore provide that
kilns that cannot meet the 0.2 ng TEQ/dscm limit would be required to
maintain the temperature at the inlet to the PMCD at no more than 400
deg.F and to limit the D/F emissions to 0.4 ng
[[Page 14201]]
TEQ/dscm. This limit of 0.4 ng TEQ/dscm is consistent with the
emissions from the Lehigh kiln during coal combustion with an estimated
PMCD inlet gas temperature of 400 deg.F.
The Agency has considered whether and how to account for emissions
variability in establishing the alternative TEQ limit of 0.4 ng/dscm in
conjunction with the 400 deg.F temperature limit at the PMCD. As
discussed in this section, available emissions data indicate that most
kilns will be able to achieve an emission level of 0.2 ng TEQ/dscm or
lower when operating the PMCD at or below 400 deg.F. Even though the
Lehigh kiln's emissions were 0.37 ng TEQ/dscm at 346 deg.F (when not
burning tires), we believe that a TEQ limit of 0.4 ng/dscm is
appropriate given the preponderance of emissions data at or below 0.2
ng TEQ/dscm. These data (given the strong indications that all units
will meet the 0.4 ng TEQ/dscm limit at temperatures of 400 deg.F or
below) suggest that using a more specific approach for variability is
not needed for this proposed standard. The Agency invites comments on
other approaches for accommodating variability in D/F emissions for NHW
cement kilns.
Thus, the proposed standard requires that the temperature at the
inlet to the PMCD be maintained at a level no greater than either: (1)
the higher of 400 deg.F or the temperature established during the
successful Method 23 performance test plus five percent (not to exceed
25 deg.F) of the temperature measured in deg.F during the successful
compliance test, if D/F emissions were determined to be no greater than
0.15 ng toxic equivalent (TEQ)/dscm (6.5 x 10-11 gr/dscf);
(2) the higher of 400 deg.F or the temperature established during the
successful Method 23 performance test, if D/F emissions were determined
to be greater than 0.15 ng toxic equivalent (TEQ)/dscm (6.5 x
10-11 gr/dscf) but less than 0.2 ng toxic equivalent (TEQ)/
dscm (8.7 x 10-11 gr/dscf);, or (3) 400 deg.F if D/F
emissions were greater than 0.2 ng TEQ/dscm (8.7 x 10-11 gr/
dscf) but less than or equal to 0.4 ng TEQ/dscm (1.7 x 10-10
gr/dscf).
Activated carbon injection (ACI) was investigated as a potential
beyond-the-MACT-floor option for existing cement kilns. Activated
carbon injection is used at one cement plant on two NHW kilns for the
purpose of reducing plume opacity. The total capital cost of an ACI
system is estimated to range from $680,000 to $4.9 million per kiln.
The total annual costs of an ACI system are estimated to range from
$426,000 to $3.3 million per kiln. These costs include the carbon
injection system and an additional baghouse to collect the carbon
separately from the existing primary particulate collector (docket item
II-B-67). Based on these costs, and considering the level of D/F
emissions achievable at the floor level of control, the Administrator
has determined that this beyond-the-floor (BTF) option for D/F MACT for
existing kilns may not be justified. Therefore the Agency is not
proposing a BTF standard. Notwithstanding these costs and the limited
emissions reductions that a BTF standard would achieve, the Agency
solicits comment on whether a BTF standard would be appropriate given
the Agency's and the Congress' special concern about D/F. D/F are some
of the most toxic compounds known due to their bioaccumulation
potential and wide range of health effects at exceedingly low doses,
including carcinogenesis. Exposure via indirect pathways was in fact a
chief reason that Congress singled out D/F for priority MACT control in
section 112(c)(6) of the Act [see S. Rep. No. 128, 101st Cong. 1st
Sess. at 154-155 (1989)]. Thus costs to reduce dioxin emissions are
frequently justified by the benefits of removing this very toxic HAP.
[See 61 FR at 17382, 17392, and 17403 (April 19, 1996) (The EPA
proposes BTF standards for D/F emissions from hazardous waste
combustion sources).] The EPA is influenced here by the fact that most
sources appear to be able to achieve the 0.2 ng TEQ/dscm BTF option
through the use of the floor technology alone, i.e. solely through the
use of temperature control. Thus, the floor standard (which facially
allows the option of 0.4 ng TEQ/dscm) in reality may be virtually
equivalent to the BTF level.
Activated carbon injection was also considered as a candidate MACT
for new cement kilns. Since no D/F performance data are available on
the existing cement kiln ACI system installed to reduce opacity, EPA
considered the performance of ACI on other potentially similar sources.
Experience with ACI on municipal waste combustors (MWCs) and medical
waste incinerators (MWIs) has led EPA to develop emission limits for D/
F for these sources in the range of 0.26 to 2.5 ng TEQ/dscm (docket
item II-J-3, docket item II-J-7). Assuming the performance level of ACI
on MWIs or MWCs to be similar to that of a cement kiln, the D/F
emissions levels achieved with ACI are expected to be about the same
level that can be achieved with temperature reduction. Therefore,
considering the level of D/F emissions achievable by PMCD inlet
temperature reduction alone, the Administrator has determined that the
temperature reduction plus ACI option for D/F MACT for new kilns may
not be justified, and the Agency is not proposing a standard based on
ACI. Notwithstanding the limited emissions reduction that such a
standard would achieve, the Agency solicits comment on whether or not
such a standard would be appropriate, given the Agency's and the
Congress' special concern about D/F. The EPA is influenced here,
similarly to the situation for existing kilns, by the fact that most
new sources appear to be able to achieve a 0.2 ng TEQ/dscm emission
level solely through the use of temperature control. Thus the proposed
standards (which facially allow a 0.4 ng TEQ/dscm emission level where
the implementation of temperature reduction may not achieve a 0.2 ng
TEQ/dscm emission level) in reality may be virtually equivalent to a
0.2 ng TEQ/dscm emission level.
For the kiln and in-line kiln/raw mill D/F emission standard, a
mass per volume concentration emission limit format was chosen. The
specific units of the emission limit are ng of D/F TEQ/dscm, referenced
to seven percent oxygen. This emission limit format has historically
been used by EPA for many air emission standards. This format is
consistent with the format of the OSW MACT standard for HW cement
kilns.12 The concentration is corrected to seven percent
oxygen to put concentrations measured in stacks with different oxygen
concentrations on a common basis. Also, the typical range of oxygen
concentrations in cement kiln stack gas is from five to 10 percent
oxygen; therefore, seven percent is representative.
---------------------------------------------------------------------------
\12\ The EPA proposed regulations for subpart EEE of 40 CFR part
63 on April 19, 1996 at 61 FR 17358.
---------------------------------------------------------------------------
A mass per volume concentration emission limit based on total D/F
congeners rather than TEQ was also considered. However, the TEQ format
was chosen in order to maintain consistency with the rule for cement
kilns which burn hazardous waste.
Kiln and in-line kiln/raw mill mercury emissions. Activated carbon
injection (ACI) was considered a potential control technology for
mercury MACT for cement kilns, since a form of this technology has been
demonstrated on medical waste incinerators and municipal waste
combustors (docket item II-A-36, pp. 98 to 99 and B-7 to B-8; docket
item II-A-11; docket item II-A-19; docket item II-A-23), and is being
used at one cement plant on two NHW kilns to reduce the opacity (docket
item II-B-35). In these
[[Page 14202]]
applications, the activated carbon (AC) is injected into the
uncontrolled exhaust gas stream ahead of the kiln PMCD.
In cement kiln applications for mercury control, the AC would need
to be injected downstream from the kiln PMCD and subsequently collected
in a separate PMCD, e.g., a baghouse. This is because the PM collected
from the kiln exhaust, i.e., cement kiln dust (CKD), is typically
recycled from the kiln PMCD back to the kiln, and in some cases may
constitute as much as 50 percent of the feed material input to the
kiln. If the AC is not injected downstream of the kiln PMCD, and then
collected in a separate PMCD downstream of the kiln PMCD, the AC would
also be recycled back to the kiln along with the adsorbed mercury. This
recycling of mercury back to the cement kiln via the AC would result in
the revaporization of the mercury in the kiln gas and ultimately the
mercury would be emitted to the atmosphere. The two cement kiln ACI
systems cannot be considered as controls for mercury for cement kilns
because they do not include provisions for injecting the AC downstream
of the kiln PMCD nor do they have the additional PMCD necessary to
remove the injected carbon from the exhaust gas stream for disposal,
but instead include the AC with the CKD that is recycled to the kiln.
Therefore there is no mercury MACT floor for new or existing kilns.
Activated carbon injection (with an additional PMCD) was
investigated as a potential beyond-the-MACT-floor option for mercury
for new and existing cement kilns. The total capital cost of an ACI
system is estimated to range from $680,000 to $4.9 million per kiln.
The total annual costs of an ACI system are estimated to range from
$430,000 to $3.3 million per kiln. These costs include the carbon
injection system and an additional baghouse necessary to collect the
carbon separately from the CKD (docket item II-B-67). The cost-
effectiveness of ACI applied to cement kilns ranges from $20,000,000 to
$50,000,000 per ton of mercury.
It is noted that the Agency has proposed a mercury emissions limit
for hazardous waste burning (HW) cement kilns (61 FR 17358), based on
the beyond-the-MACT-floor option of ACI. However, mercury levels in
hazardous waste fuels per million BTU of heat input are generally
higher than mercury levels in coal that is fired in non-hazardous waste
burning (NHW) cement kilns. Thus, HW cement kilns generally have higher
mercury emissions than NWH cement kilns. Further, the available data
indicate that existing mercury emissions from essentially all
individual NHW cement kilns are lower than the beyond-the-MACT-floor
emission limit that is now being considered by the Agency to be
promulgated for HW cement kilns. Based on the relatively low levels of
existing mercury emissions from individual NHW cement kilns, and the
costs of reducing these emissions by ACI, the Administrator has
determined that this beyond-the-MACT-floor option for reducing mercury
from new and existing NHW kilns may not be justified. Thus, the Agency
is not proposing a mercury standard for new and existing NHW cement
kilns.
Notwithstanding the reasons for not proposing a mercury standard
for NHW cement kilns, the Agency solicits comment on whether a BTF
standard would be appropriate given the Agency's and Congress' special
concern about mercury. Mercury is one of the more toxic metals known
due to its bioaccumulation potential and the adverse neurological
health effects at low concentrations especially to the most sensitive
populations at risk (i.e. unborn children, infants and young children).
In addition, as with D/F, Congress has singled out mercury in section
112(c)(6) of the Act for prioritized control. Furthermore, the amount
of mercury emitted by these sources is not inconsequential, roughly
10,000 pounds annually (or about 60 pounds per kiln annually) making
NHW cement kilns a significant source of mercury emissions that may
warrant attention under section 112(c)(6) of the Act depending on what
other opportunities for controlling mercury from other significant
sources are available.
It is EPA's tentative conclusion, however, that concerns as to
health risks from mercury emissions from these sources may be
appropriately addressed pursuant to the timetable set out in the Act,
namely through the residual risk determination process set out in
section 112(f) of the Act. A more accelerated determination may be
warranted, however, for other mercury-emitting sources, in particular
hazardous waste combustion sources, where there are special
considerations of immediately protective rules imposed by the Resource
Conservation and Recovery Act. [See 61 FR at 17369-17370 (April 19,
1996).]
Kiln and in-line kiln/raw mill THC main exhaust emissions. Based on
data from 31 tests conducted at 16 NHW kilns (docket item II-B-75), THC
emissions varied between 0.4 ppmvd and 224 ppmvd (as propane, corrected
to seven percent oxygen). With the exception of two kilns which employ
a precalciner system with no preheater, no add-on air pollution control
technologies are presently in use that decrease emissions of THC (the
surrogate for organic HAPs) from NHW cement kilns. On this basis the
MACT floor for THC emissions from existing kilns and in-line kiln/raw
mills is no control.
The precalciner/no preheater system was considered as a possible
beyond-the-floor technology for existing kilns and as a possible MACT
floor for new kilns (docket item II-B-47, docket item II-B-48). The
precalciner/no preheater technology acts like an afterburner to combust
organic material in the feed. However, it was found to increase fuel
consumption 79 percent relative to the preheater/precalciner designs
(docket item II-B-48, docket item II-D-199). The EPA estimates that
precalciner/no preheater kilns would emit six times as much
SO2 (at 3.7 lb SO2/ton clinker), two and one half
times as much NOX (at 9.8 lb NOX/ton clinker),
and 1.2 times as much CO2 (at 2,086 lb CO2/ton
clinker) as a preheater/precalciner kiln of equivalent clinker capacity
(docket item II-B-48). For a 600,000 ton clinker/year kiln, increased
emissions for a flash precalciner relative to a preheater/precalciner
are: 930 tpy SO2, 1,740 tpy NOX, and 109,000 tpy
CO2 (docket item II-B-76, docket item II-D-199).
One THC control method available is feed material selection. Total
hydrocarbon emissions from kilns can be limited by avoiding feed
materials which have excessive organic contents (docket item II-I-66,
docket item II-I-67, docket item II-I-68). A few existing kilns have
employed this method, but not enough to constitute a MACT floor for
existing kilns. Also, this method is not available for existing kilns
in that facilities are generally tied to existing raw materials sources
in close proximity to the facility. Raw material proximity
(transportation cost) is usually a major factor in plant site
selection. Feed material selection can be employed in the siting
process for new kilns, and to a limited extent at existing kilns.
The precalciner/no preheater technology was also considered as a
MACT floor for new sources but, when NOX, SO2,
and CO2 emissions and energy penalties are considered, the
Administrator has determined that it does not represent the MACT floor
for new sources, since the kilns employing this technology cannot be
considered to be the best controlled similar source. The combination of
feed material selection, site location and feed material blending was
determined to be MACT for new sources, in that this method has been
used at some existing sources and that site selection based on
availability
[[Page 14203]]
of acceptable raw material hydrocarbon content is feasible.
The numerical emission limit proposed for THC from the main exhaust
of new kilns and new in-line kiln/raw mills is 50 ppmvd (as propane,
corrected to seven percent oxygen). This represents a level which is
consistently achievable, as shown by tests across a broad spectrum of
feed material compositions, when feeds with high organic contents are
avoided. Based on the available THC main exhaust concentration data for
existing NHW kilns, approximately 62 percent of the tested NHW kilns
could meet the 50 ppmvd limit (docket item II-B-75).
For the new kiln and in-line kiln/raw mill main exhaust THC
emission standard, a volume per volume concentration emission limit
format was chosen. The specific units of the emission limit are ppmvd
(as propane, corrected to seven percent oxygen). This emission limit
format has historically been used by EPA for many air emission
standards. This format is consistent with the format of the OSW MACT
standard for HW cement kilns.13 The concentration is
corrected to seven percent oxygen to put concentrations measured in
stacks with different oxygen concentrations on a common basis, and
because the typical range of oxygen concentrations in cement kiln stack
gas is from five to 10 percent oxygen; therefore, seven percent is
representative. The THC concentration can be monitored directly with
the CEM required by this standard. The reference or calibration gas for
the THC CEM is propane, and the data analyzed in the development of
this standard were referenced to propane, therefore propane is the
appropriate reference compound for concentration data.
---------------------------------------------------------------------------
\13\ The EPA proposed regulations for subpart EEE of 40 CFR Part
63 on April 19, 1996 at 61 FR 17358.
---------------------------------------------------------------------------
Kiln and in-line kiln/raw mill HCl emissions. No technologies that
control HCl emissions have been identified that are currently being
used by more than six percent of the cement kilns in the U.S. For this
reason, there is no MACT floor for existing kilns. One technology
considered as potential MACT for new kilns was an alkaline scrubber,
since two kilns in the U.S. operate scrubbers to control SO2
emissions. However, these SO2 scrubbers are operated only
intermittently (docket item II-D-196) and thus cannot be considered
best controlled similar source. For this reason there is no MACT floor
for new kilns.
Alkaline scrubbers were considered as a beyond-the-floor option for
HCl control. Based on engineering assessment of HCl scrubbers used in
MWC and MWI applications and transfer of similar technology to the
cement industry and on vendor design information (docket item II-D-36),
an alkaline scrubber could achieve 15 ppmv HCl outlet concentration at
low inlet HCl loadings or at least 90 percent removal with an inlet HCl
level of 100 ppmv or greater. Based on this estimated performance,
annual emission reduction estimates range from 12 tpy of HCl and 27 tpy
of SO2 to 200 tpy of HCl and 600 tpy of SO2 per
kiln (docket item II-B-67). The total capital cost of installing an
alkaline scrubber on an existing kiln is estimated to range from
$980,000 to $4.6 million. The total annual cost is estimated to range
from $300,000 to $1.5 million per kiln (docket item II-B-67).
Based on the costs of control and the emissions reductions that
would be achieved, the Administrator has determined that beyond-the-
floor controls are not warranted. Therefore, there is no proposed
emission limit for HCl from new and existing NHW kilns and NHW in-line
kiln/raw mills. Analyses indicate that the ambient concentrations of
HCl produced by emissions from existing NHW kilns and in-line kiln/raw
mills are below the health effects reference concentration for HCl
(docket item II-B-71).
Clinker cooler PM HAP emissions. Particulate emissions from clinker
coolers are typically controlled by FFs (docket item II-B-69). In the
portland cement manufacturing industry, it is estimated that at least
54 existing clinker coolers (docket item II-A-4) are subject to the
requirements of the NSPS for cement plants (40 CFR part 60, subpart F).
This number represents about 25 percent of clinker coolers and,
therefore, the NSPS represents the MACT floor. The NSPS level of
control is being achieved through the use of well-designed and well-
operated FFs. Typical design parameters for pulse jet cleaned fabric
filters applied to clinker coolers are air-to-cloth ratios in the range
of 0.02 cubic meters per second per square meter (m3/sec)/
m2 [4 actual cubic feet per minute per square foot (acfm/
ft2)] to 0.046 (m3/sec)/m2 (9 acfm/
ft2).
Table 10 lists plants and the results of emission tests performed
on FFs applied to clinker coolers from the May 1985 NSPS review report
(docket item II-A-4).
Table 10.--Fabric Filter Controlled Clinker Cooler Test Results
[Docket Item II-A-4]
------------------------------------------------------------------------
PM stack emissions (kg/Mg dry feed) Plant and location
------------------------------------------------------------------------
0.0041................................. Kaiser Cement--Cupertino, CA.
0.004.................................. Moore McCormack--Knoxville, TN.
0.022.................................. Moore McCormack--Brooksville,
FL.
0.003 a................................ Kaiser Cement--Lucerne Valley,
CA.
0.02................................... California Portland--Mojave,
CA.
0.017.................................. Martin Marietta--Leamington, UT
0.025.................................. Kaiser--San Antonio, TX.
0.03 b................................. Lone Star--Cape Girardeau, MO.
0.002.................................. Monolith Portland--Laramie, WY.
0.024.................................. Ash Grove--Louisville, NE.
0.09552 b.............................. Ideal Basic--La Porte, CO.
0.0117................................. Texas Industries--Hunter, TX
0.0245................................. Lone Star--Salt Lake City, UT.
------------------------------------------------------------------------
a Includes alkali bypass emissions.
b Include raw mill emissions.
The data shown are short-term performance measurements at cement
plants that became subject to the NSPS subsequent to the 1979 NSPS
review. The data in Table 10 served as the basis for the decision on
the 1985 NSPS review to keep the emission limit established by the
original NSPS for clinker cooler PM emissions at 0.05 kg/Mg of dry feed
(.1 lb/ton of dry feed). Because no other PM data on clinker coolers
became available as a result of this rule development, the Agency is
relying on these same data (and interpretation thereof) in establishing
the MACT floor for clinker coolers. The results for FFs serving only
clinker coolers ranged from 0.002 to 0.025 kg/Mg of dry feed, all of
which were in compliance with the NSPS. These data represent the
performance level achieved by FFs designed to meet the NSPS level of
control. No technologies were identified for existing or new sources
that would achieve significant additional reductions in PM or metal HAP
emissions; consequently, there is no beyond-the-floor technology and
the MACT for new clinker coolers is also the NSPS level. Therefore the
PM emission limit proposed for new and existing clinker coolers is 0.05
kg/Mg dry feed (0.10 lb/ton dry feed), which is equivalent to the NSPS
limit. An opacity limit of 10 percent (which is required under the
NSPS) is also being proposed.
The production-based emission limit format was chosen for clinker
cooler PM emissions. The units for this emission standard are kg of PM
per Mg of dry feed (lb PM per ton of dry feed). This
[[Page 14204]]
format (mass per unit of production) and associated opacity limit is
consistent with the format of the portland cement plant NSPS (40 CFR
part 60, subpart F).
Raw material dryer and materials handling processes opacity.
Particulate matter emissions from raw material dryers and materials
handling processes at portland cement plants are typically captured by
enclosures (total or partial) and/or hooding of transfer points. In
most cases, the exhaust gases are directed to FF systems. At least 31
portland cement plants (docket item II-A-4) have some affected sources
that are subject to the requirements of the NSPS for portland cement
plants (40 CFR part 60, subpart F). No technologies which are more
efficient than FFs are in use for these affected sources. State agency
personnel indicated that none of the facilities had problems meeting
the NSPS opacity limit of 10 percent (docket item II-A-4, docket item
II-B-71). The design characteristics of FFs applied to these emission
sources include air-to-cloth ratios ranging from 0.02 (m 3/
sec) /m 2 (4 acfm/ft 2) to 0.041 (m 3/
sec) /m 2 (8 acfm/ft2) at pulse-jet and pulsed-
plenum cleaning systems in installations subject to the NSPS since the
1979 NSPS review (docket item II-A-4, II-I-43). Therefore, the MACT
floor technology for control of PM emissions from portland cement
materials handling processes and raw material dryers is a combination
of total enclosures, partial enclosures, or hooding with FF systems. No
beyond-the-floor technologies for control of PM from raw material
dryers and materials handling processes were identified.
The emission limit established by the NSPS for raw material dryers
and materials handling process PM emissions (surrogate for HAP metals)
is an opacity limit of 10 percent. Given that no more effective
technologies were identified, the emission limit corresponding to the
MACT floor, which is the NSPS, is being proposed as MACT for PM
emissions from new and existing portland cement materials handling
processes and raw material dryers.
The proposed standard for PM emissions from new and existing
materials handling systems and raw material dryers is an opacity limit
of 10 percent. An opacity limit format was chosen for these affected
sources because it is consistent with the NSPS format for these
facilities.
Raw material dryer THC. Some plants may dry their raw materials in
separate dryers prior to or during grinding (docket item II-I-43,
p.750). This drying process can potentially lead to organic HAP and THC
emissions in a manner analogous to the release of organic HAPs and THC
emissions from kilns when hot kiln gas contacts incoming feed
materials. The method available for reducing THC emissions (and organic
HAPs) is the same technology described for reducing THC emissions from
kilns and in-line kiln/raw mills. Therefore, the combination of feed
material selection, site location and feed material blending was
determined to be MACT for new sources. The numerical emission limit
proposed for THC from new raw material dryers is 50 ppmvd reported as
propane, corrected to seven percent oxygen. This represents a level
which is consistently achievable when feeds with high organic contents
are avoided.
E. Selection of Testing and Monitoring Requirements
Testing requirements are being proposed for demonstrating
compliance with all standards. Initial performance tests for all
affected sources/pollutant combinations would demonstrate compliance
with emission limits. These tests would be repeated every 5 years for
PM from NHW kilns (including alkali bypasses), NHW in-line kiln/raw
mills (including alkali bypasses), clinker coolers, raw material dryers
and materials handling processes, and for D/F from kilns and in-line
kiln/raw mills. Site-specific monitoring parameters would be
established during the initial and subsequent performance tests for D/F
from kilns and in-line kiln/raw mill systems. A PMCD inlet temperature
parameter would be used to ensure continuous compliance with the D/F
emission limit. The following paragraphs present the rationale for the
selection of the proposed testing, test methods, and monitoring
requirements for each affected source and associated pollutant.
1. Kiln and In-line Kiln Raw Mill PM Emissions
The proposed standards would require the owner or operator of an
affected NHW kiln or NHW in-line kiln/raw mill to conduct initial and
periodic (every 5 years) performance tests using appropriate existing
EPA reference methods in 40 CFR part 60, appendix A. Method 5 would be
used to demonstrate compliance with the NHW kiln and NHW in-line kiln/
raw mill PM emission limits. (A determination of the particulate matter
collected in the impingers [the ``back half''] of the Method 5
particulate sampling train would not be required.) Method 5 is the
long-standing EPA method for making PM determinations from stationary
sources. Each performance test would consist of three runs conducted
under representative operating conditions. Each run would have a
minimum sampling volume of 0.85 dscm (30 dscf) and a minimum duration
of 1 hour. The average of the three runs would be used to determine
compliance. Method 5, as proposed, is currently required to demonstrate
compliance with the NSPS.
If the kiln is equipped with a separate alkali bypass, PM emissions
from the alkali bypass would be determined by a simultaneous Method 5
test and the combined emissions from the main exhaust and the alkali
bypass would be subject to the PM emission limit.
Owners or operators of in-line kiln/raw mills would be required to
conduct a compliance demonstration with the raw mill in operation and a
separate compliance demonstration when the raw mill is not in
operation, since emissions may vary depending on the operating status
of the raw mill.
A COM would be required to ensure continuous compliance with the
standard. During the initial Method 5 performance test, the owner or
operator would use a COM to demonstrate compliance with the kiln and
in-line kiln/raw mill opacity limit. If there is an alkali bypass, a
COM would be required for the alkali bypass and compliance with the
opacity limit would also be demonstrated for the alkali bypass during
the initial Method 5 performance test.
If the PM control device exhausts through a monovent, or if the use
of a COM in accordance with the installation specifications of PS-1 of
40 CFR part 60, appendix B were not feasible, a test in accordance with
Method 9 of appendix A to 40 CFR part 60 would be conducted at the same
time as the Method 5 performance test. If the control device exhausts
through multiple stacks, the owner or operator would have the option of
conducting a Method 9 test in lieu of installing COMs.
The opacity limit would be 20 percent and would apply to both main
and alkali bypass stacks. Exceedance of the kiln or in-line kiln/raw
mill opacity limit, or the alkali bypass opacity limit, for any 30-
minute average would constitute a violation of the kiln or in-line
kiln/raw mill PM emission limit. Owners or operators of in-line kiln/
raw mills would demonstrate compliance with the opacity limits during
initial performance tests to be conducted while the raw mill is
operating and while the raw mill is not operating.
If the 30-minute average opacity exceeded 15 percent for any ten
consecutive 30-minute periods as
[[Page 14205]]
determined by the COM, or if any 30-minute average opacity exceeded 15
percent as determined by a daily Method 9 test, the owner or operator
would be required to initiate a site-specific operating and maintenance
(O and M) plan within one hour. The O and M plan would be required as
part of the permit application submitted in accordance with part 70 of
this chapter, and would address procedures for proper operation and
maintenance of the affected source and the APCD and the corrective
action to be taken.
If the 30-minute average opacity exceeded 15 percent for five
percent or more of the kiln operating time as determined by COM, or if
the 30-minute average opacity reading exceeded 15 percent during five
percent or more of the daily Method 9 readings in any 6-month reporting
period, the owner or operator would be required to notify the
permitting authority within 48 hours and to develop and implement a
quality improvement plan (QIP) within 180 days. The QIP would address
improved maintenance practices, process operation changes, appropriate
improvements in control methods, other appropriate steps to improve
performance and more frequent or improved monitoring. If the owner or
operator determined that more than 180 days will be necessary to
complete the appropriate improvements, the owner or operator would be
required to notify the permitting authority and obtain a site-specific
resolution subject to the approval of the permitting authority.
Each COM would be required to be designed, installed, and operated
in accordance with PS-1. The use of COMs would provide a timely and
direct indication of increased emissions. A COM gives an immediate
indication of an exceedance, and provides for timely action that will
minimize the duration and, therefore, the emissions of an upset. A COM
can also signal the long-term gradual deterioration of performance of a
control device. Failure of any 30-minute average reading to meet the
opacity limit would constitute a violation of the NHW kiln and NHW in-
line kiln/raw mill PM emission limit.
Where the use of a COM is not feasible (or at the option of the
owner or operator when the exhaust is discharged through multiple
stacks), the proposed standards would require daily visual observations
using Method 9. The duration of the Method 9 test would be 30 minutes.
Method 9 is the established EPA method for visual determinations of
opacity from stationary sources. Method 9 procedures for making visual
observations and reducing the data would be followed. Failure of any
30-minute average reading during the daily test to meet the opacity
limit would constitute a violation of the NHW kiln and NHW in-line
kiln/raw mill PM emission limit.
The EPA proposed that HW cement kilns [and other hazardous waste
combusters (HWCs)] maintain continuous compliance with the PM standard
through the use of a PM continuous emissions monitoring system (CEMS).
[See 61 FR at 17358 (April 19, 1996).] As discussed in the proposed HWC
rule 14 PM CEMS are commercially available and currently in
use in Europe. For example, PM CEMS are installed for compliance
assurance purposes in the European Union (EU) for the EU HWC PM
standard.
---------------------------------------------------------------------------
\14\The EPA proposed regulations for subpart EEE of 40 CFR part
63 on April 19, 1996 at 61 FR 17358.
---------------------------------------------------------------------------
The proposal to require HWCs to install a PM CEMS is predicated on
a successful vendor (with EPA oversight) demonstration test program on
a hazardous waste incinerator. The purpose of the demonstration test
program is to verify that at least one PM CEMS can meet the proposed
performance specifications. The testing program consists of a
demonstration test and a long term endurance test. The demonstration
test involves installing the CEMS and carrying out all of the tests
prescribed in the performance specifications. The long term endurance
test will involve evaluating (at least one) CEMS for a minimum of six
months. The purpose of this test is to evaluate the PM CEMS for
accuracy, daily drift, availability (i. e. up time), ruggedness, and
maintenance over an extended period. The demonstration test program
began in 1996 and it is anticipated that the program will conclude in
1997. The Agency will notice the results and conclusions of the
demonstration test program in the docket for the hazardous waste
combustor rule. Considering the outcome of the demonstration test
program and other relevant information received or developed by EPA,
the Agency will reevaluate the monitoring requirements for NHW cement
kilns. The EPA intends to include a requirement for PM CEMs in the
final rule, unless the analysis of existing or newly acquired data and
information shows this type of monitoring is not appropriate. The
Agency will notice the results of this reevaluation in the docket for
the NHW cement kiln rule.
2. Kiln D/F Emissions
The proposed standards would require the owner or operator of an
affected kiln or in-line kiln/raw mill to conduct initial and periodic
(every five years) performance tests using appropriate existing EPA
methods in 40 CFR part 60, appendix A. Method 23 is the established
method for determining D/F concentration. Each performance test would
consist of three runs conducted under representative operating
conditions. Each run must be at least 3 hours duration with a minimum
sampling volume of 2.5 dscm. The average of the three runs would be
used to determine compliance.
If the kiln is equipped with an alkali bypass, D/F emissions from
the alkali bypass would also be subject to Method 23 testing
requirements and the emissions from the alkali bypass would be subject
to the D/F emission limit. Furthermore, in-line kiln/raw mills would be
required to conduct a compliance demonstration with the raw mill in
operation and a separate compliance demonstration when the raw mill is
not in operation. However, if an in-line kiln/raw mill has an alkali
bypass, a compliance demonstration for the alkali bypass would only be
required when the raw mill is operating.
There is no CEM available for D/F emissions and no suitable
surrogate pollutant that could be monitored continuously. Therefore,
for D/F emissions from an affected NHW kiln or NHW in-line kiln/raw
mill, the proposed standards would require continuous monitoring and
recording of the kiln exhaust gas temperature at the inlet to the kiln
PMCD. If the kiln is equipped with an alkali bypass the proposed
standards would also require continuous monitoring and recording of the
gas temperature at the inlet to the alkali bypass PMCD.
A kiln-specific maximum temperature limit would be established
during the performance test. The temperature would be continually
measured during the D/F performance test. The average temperature for
each of the three runs would be determined, and the average of these
three averages would, in some cases, be used to establish the kiln-
specific temperature limit. When the D/F performance test emissions
were 0.15 ng TEQ/dscm or less (corrected to seven percent oxygen), the
kiln-specific maximum temperature would be the higher of 400 deg. F or
the average temperature of the performance test plus five percent (not
to exceed 25 deg. F) of the temperature measured in deg.F. When the D/
F performance test emissions (corrected to seven percent oxygen) were
greater than 0.15 ng TEQ/dscm but did not exceed 0.20 ng TEQ/dscm, the
kiln-specific maximum temperature would be the higher of 400 deg. F or
the average temperature of the performance test. If D/F emissions
(corrected to seven
[[Page 14206]]
percent oxygen) are greater than 0.2 ng/dscm TEQ but less than 0.4 ng/
dscm TEQ during the performance test, then the kiln specific
temperature limit would be set at 400 deg. F. (If D/F emissions exceed
0.4 ng/dscm, corrected to seven percent oxygen, the performance test
would be unsuccessful and the kiln or in-line kiln/raw mill would not
be in compliance with the standard.) The temperature would provide a
direct indication of D/F emissions from the kiln or in-line kiln/raw
mill and would be directly enforceable for compliance determinations.
Owners or operators of kilns and in-line kiln/raw mills equipped
with alkali bypasses would establish a separate alkali bypass PMCD
inlet temperature limit for the alkali bypass during the performance
test. This limit would be based on the temperature at the inlet to the
alkali bypass PMCD and would be established in the same manner as the
kiln specific temperature limit. Owners or operators of in-line kiln/
raw mills equipped with alkali bypasses would establish the temperature
limit for the alkali bypass PMCD inlet during the performance test with
the raw mill operating.
The proposed averaging period for inlet temperature to the PMCD is
9 hours, because the compliance test for D/F consists of 3-three hour
manual tests which are averaged. Thus the inlet temperature limit is
established as the average temperature level achieved over the three D/
F runs in a performance test.
The Agency specifically requests comment on whether a 9-hour block
average site-specific temperature limit is sufficient to ensure
compliance with the D/F standard. Because EPA is concerned that D/F
emissions emitted during high temperature episodes may not
correspondingly be offset by low emissions during lower temperature
episodes due to the non-linear relationship between dioxin formation
and temperature, a 9-hour block average may not be adequate to ensure
compliance with the D/F standard in some instances. The Agency
addressed this concern in the proposal for HW combustion sources
(cement kilns) [61 FR at 17424, (April 19, 1996)]. There, EPA proposed
a site-specific ten-minute rolling average to control perturbations in
temperature and a site-specific, one-hour rolling average to control
average inlet PMCD temperatures. The ten-minute average was proposed to
address the concern that short-term perturbations above the limit may
result in D/F emissions that may not be offset by lower emissions at
lower temperatures. The one-hour averaging period was proposed to limit
average temperatures. Thus, in today's proposal, the Agency requests
comment on whether a shorter-term block or rolling average limit (i.
e., less than 9 hours) is more appropriate than the one proposed, or
whether a short-term limit in conjunction with the proposed 9-hour
block average is needed to properly ensure compliance with the D/F
standard. The EPA further notes that it may also take these comments
into account in considering what averaging time to adopt for hazardous
waste combustion sources.
If carbon injection is used for D/F control, a kiln-specific (and
where applicable, an alkali bypass-specific) carbon injection rate for
each run would be established during the performance test. The average
carbon injection rate for the three runs would be calculated. This
carbon injection rate would serve as an additional monitoring limit and
would be required to be maintained or exceeded for every 9-hour period
of kiln operation. The carbon injection rate would provide a direct
indication of D/F emissions from the kiln and would be directly
enforceable for compliance determinations.
3. Kiln and Raw Material Dryer THC Emissions
The proposed standards applicable to new NHW kiln main exhausts,
new NHW in-line kiln/raw mill main exhausts and new raw material dryers
would require the owner or operator to conduct an initial performance
test of THC emissions from an affected source using a THC CEM and to
demonstrate continuous compliance with the THC concentration limit of
50 ppmvd reported as propane (corrected to 7 percent oxygen), through
operation of a THC CEM. The use of THC CEMs was selected as the
monitoring method because these instruments are available, accurate and
reliable, and when calibrated with propane provide an output which is
consistent with the THC standard. Each THC CEM would be required to be
designed, installed, and operated in accordance with PS-8A of 40 CFR
part 60, appendix B 15. The performance test would be of 3
hours duration. To determine compliance with the THC emission
concentration limit, a 30-day block averaging period would be used. Any
exceedance of the THC emission concentration limit over any 30-day
block averaging period would constitute a violation of the new NHW kiln
and in-line kiln/raw mill THC standard, or the new raw material dryer
THC standard.
---------------------------------------------------------------------------
\15\ The EPA proposed amendments to appendix B of 40 CFR part 60
on April 19, 1996, at 61 FR 17358.
---------------------------------------------------------------------------
The rationale for the 30-day block averaging time is that the
organic content of the feed material may vary with quarry or mine
location. Once raw material storage bins are filled with high organic
content feed material and an excursion is experienced, it may take a
considerable amount of time to consume these already stored feed
materials and locate/obtain feed materials with lower organic content.
4. Clinker Cooler PM Emissions
As in the case with NHW kiln and NHW in-line kiln/raw mill PM
emissions, the proposed standards would require the owner or operator
of an affected clinker cooler to conduct initial and periodic (every 5
years) performance tests using EPA Method 5 of 40 CFR part 60, appendix
A. Method 5 is the long-standing method for making PM determinations
from stationary sources. (A determination of the particulate matter
collected in the impingers [``back half''] of the Method 5 particulate
sampling train would not be required.) Each performance test would
consist of three runs conducted under representative operating
conditions. Each run would have a minimum sampling volume of 0.85 dscm
(30 dscf) and a minimum duration of 1-hour. The average of the three
runs would be used to determine compliance with the PM limit. Method 5
is currently required to demonstrate compliance with the NSPS.
The opacity limit for clinker coolers is 10 percent. The proposed
clinker cooler emissions monitoring requirements are the same as the
proposed requirements for affected NHW kilns and NHW in-line kilns/raw
mills. A COM would be required to ensure continuous compliance with the
standard. During the initial Method 5 performance test, the owner or
operator would use a COM to demonstrate initial compliance with the
opacity limit.
If the control device exhausts through a monovent, or if the use of
a COM in accordance with the installation specifications of PS-1 of 40
CFR part 60, appendix B were not feasible, a Method 9 test would be
conducted at the same time as the Method 5 performance test. If the
control device exhausts through multiple stacks, the owner or operator
would have the option of conducting a Method 9 test in lieu of
installing COMs. Exceedance of the clinker cooler opacity limit for any
30-minute average would constitute a violation of the clinker cooler PM
emission standard.
Each COM would be required to be designed, installed, and operated
in accordance with PS-1. The use of COMs
[[Page 14207]]
would provide a timely and direct indication of increased emissions. A
COM gives an immediate indication of an exceedance, and provides for
timely action that will minimize the duration and, therefore, the
emissions of an upset. A COM can also signal the long-term gradual
deterioration of performance of a control device. Failure of any 30-
minute average reading to meet the clinker cooler opacity limit would
constitute a violation of the clinker cooler PM emission standard.
Where the use of a COM is not feasible (or at the option of the
owner or operator when the exhaust is discharged through multiple
stacks), the proposed standards would require daily visual observations
using Method 9. The duration of the Method 9 test would be 30 minutes.
Method 9 is the established EPA method for visual determinations of
opacity from stationary sources. Method 9 procedures for making visual
observations and reducing the data would be followed. Failure of any
daily reading to meet the 10 percent opacity limit would constitute a
violation of the clinker cooler PM emission limit.
5. Raw and Finish Mill PM Emissions
The proposed standards would require the owner or operator of raw
and finish mills to conduct initial and periodic (every five years)
compliance tests using Method 9, and to either install, calibrate,
maintain and operate a bag leak detection system or to conduct daily
visual observations using Method 22 to ensure compliance with the
opacity standard. The opacity limit for raw and finish mills is 10
percent. The duration of the Method 9 tests is 3-hours and the duration
of the daily Method 22 tests is six minutes. The duration of the Method
9 test can be reduced to one hour if during the first hour of the test,
there are no individual readings greater than 10 percent and there are
no more than three individual readings of 10 percent.
If visible emissions are detected during any daily Method 22 test,
the owner or operator must begin a 30-minute Method 9 test within 24
hours and initiate a site specific operating and maintenance plan
within one hour. If the bag leak detection system alarm is triggered,
the owner or operator must initiate a site specific operating and
maintenance plan within one hour. Failure to conduct a Method 9 test as
required, failure to initiate a site-specific operating and maintenance
plan as required, or observation of any 30-minute average opacity in
excess of 10 percent during the Method 9 test shall constitute a
violation of the raw mill and finish mill opacity standard.
6. Raw Material Dryer and Materials Handling Processes PM Emissions
The proposed standards would require the owner or operator of raw
material dryers and materials handling processes to conduct initial and
periodic (every five years) performance tests of visual emissions.
Particulate matter emissions from these sources are much lower than
those from kilns, clinker coolers, and raw and finish mills, therefore,
continuous opacity monitoring, and more frequent visual opacity
measurements are not being proposed. Method 9 of 40 CFR part 60,
appendix A is the proposed method for the visual opacity measurements.
As previously noted, Method 9 is the established method for opacity
determinations for stationary sources, and provides a directly
enforceable opacity reading for compliance determinations.
Section 63.6(h)(5)(ii) of the NESHAP general provisions (40 CFR
part 63, subpart A) requires 3 hours (30 6-minute averages) of Method 9
observations for determining compliance for fugitive emission sources.
However, due to the potentially large number of affected materials
handling sources at portland cement plants, the costs for observations
from these sources are considered overly burdensome. Furthermore, data
from similar facilities in non-metallic mineral processing plants
(docket item II-J-10) show that the opacity readings for the first hour
are typically the same as the readings for the second and third hours.
Therefore EPA is proposing a reduction in Method 9 testing duration for
these facilities to one hour (ten 6-minute averages), provided that no
individual reading exceeds 10 percent and that no more than three
individual readings of ten percent are observed during the first hour
of the test. Exceedance of the 10-percent opacity limit for any 30-
minute average reading would constitute a violation of the proposed
opacity standard.
7. General Monitoring Requirements
The general provisions in 40 CFR part 63, subpart A require each
owner or operator to develop and implement a startup, shutdown, and
malfunction plan. The proposed NESHAP requires the owner or operator to
include procedures to be followed in the event that a CEM, COM or
temperature monitor indicates that emissions exceed the applicable
standards. Block averages are proposed for opacity, D/F, and THC
monitoring required by the standard.
Owners or operators are also required to develop site specific
operating and maintenance plans as part of the part 70 permit
application process. Such plans are applicable to the operation and
maintenance of kilns, in-line kiln/raw mills, raw mills and finish
mills and the PM APCDs associated with these affected sources.
F. Selection of Notification, Recordkeeping, and Reporting Requirements
The proposed NESHAP would require portland cement manufacturing
plants to comply with all applicable requirements in the NESHAP general
provisions (40 CFR part 63, subpart A), including recordkeeping,
notification, and reporting requirements. General recordkeeping
requirements would include relevant records for each affected source
of: (1) The occurrence and duration of each startup, shutdown, or
malfunction of operation of process equipment, (2) the occurrence and
duration of each malfunction of the air pollution control equipment,
(3) all maintenance performed on the air pollution control equipment,
(4) actions taken during startup, shutdown and malfunction that are
different from the procedures specified in the source's startup,
shutdown, and malfunction plan, (5) all information necessary to
demonstrate conformance with the affected source's startup, shutdown,
and malfunction plan when the plan procedures are followed, (6) each
period during which a CMS is malfunctioning or inoperative (including
out-of-control periods), (7) all required measurements needed to
demonstrate compliance with the standards, (8) all results of
performance tests, CMS performance evaluations, and opacity and visible
emissions observations, (9) all measurements as may be necessary to
determine the conditions of performance tests and performance
evaluations, (10) all CMS calibration checks, (11) all adjustments and
maintenance performed on CMS, (12) any information demonstrating
whether a source is meeting the requirements for a waiver of record
keeping or reporting requirements, (13) all emission levels relative to
the criterion for obtaining permission to use an alternative to the
relative accuracy test, (14) all records or any bag leak detection
system alarm, and (15) all documentation supporting initial
notifications and notifications of compliance status. Records would
also be required of applicability determinations that the source is not
subject to the requirements of the NESHAP and of CMS measurements,
operation, and malfunctions.
General Provisions notification requirements would include: (1)
initial
[[Page 14208]]
notifications, (2) notification of performance test, (3) notification
of opacity and visible emission observations, (4) additional
notifications required for sources with CMS and (5) notification of
compliance status. Notifications of the requirement to develop and
implement a QIP, and if applicable, notifications of the inability to
implement a required QIP within 180 days would also be required by this
subpart. Reporting requirements would include (1) a report of
performance test results, (2) a report of results of opacity or visible
emission observations done concurrently with performance test, (3)
progress reports if required as a condition of receiving an extension
of compliance, (4) periodic and immediate startup, shutdown, and
malfunction reports, and (5) summary excess emissions and performance
monitoring reports.
VI. Public Participation
The EPA seeks full public participation in arriving at its final
decisions and encourages comments on all aspects of this proposal from
all interested parties. Full supporting data and detailed analyses
should be submitted with comments to allow EPA to make maximum use of
the comments. All comments should be directed to the Air and Radiation
Docket and Information Center, Docket No. A-92-53 (see ADDRESSES).
Comments on this notice must be submitted on or before the date
specified in DATES.
Commenters wishing to submit proprietary information for
consideration should clearly distinguish such information from other
comments and clearly label it ``Confidential Business Information''
(CBI). Submissions containing such proprietary information should be
sent directly to the Emission Standards Division CBI Office, U.S.
Environmental Protection Agency (MD-13), Research Triangle Park, North
Carolina 27711, with a copy of the cover letter directed to the contact
person listed above. Confidential business information should not be
sent to the public docket. Information covered by such a claim of
confidentiality will be disclosed by EPA only to the extent allowed and
by the procedures set forth in 40 CFR part 2. If no claim of
confidentiality accompanies the submission when it is received by EPA,
it may be made available to the public without further notice to the
commenter.
VII. Administrative Requirements
A. Docket
The docket is an organized and complete file of all the information
considered by EPA in the development of this rulemaking. The docket is
a dynamic file, because material is added throughout the rulemaking
development. The docketing system is intended to allow members of the
public and industries involved to readily identify and locate documents
so that they can effectively participate in the rulemaking process.
Along with the proposed and promulgated standards and their preambles,
the contents of the docket will serve as the record in the case of
judicial review. [See section 307(d)(7)(A) of the Act.]
B. Public Hearing
A public hearing will be held, if requested, to discuss the
proposed standards in accordance with section 307(d)(5) of the Act.
Persons wishing to make oral presentations on the proposed standards
should contact EPA (see ADDRESSES). If a public hearing is requested
and held, EPA will ask clarifying questions during the oral
presentation but will not respond to the presentations or comments. To
provide an opportunity for all who may wish to speak, oral
presentations will be limited to 15 minutes each. Any member of the
public may file a written statement on or before May 26, 1998. Written
statements should be addressed to the Air and Radiation Docket and
Information Center (see ADDRESSES), and refer to Docket No. A-92-53.
Written statements and supporting information will be considered with
equivalent weight as any oral statement and supporting information
subsequently presented at a public hearing, if held. A verbatim
transcript of the hearing and written statements will be placed in the
docket and be available for public inspection and copying, or mailed
upon request, at the Air and Radiation Docket and Information Center
(see ADDRESSES).
C. Executive Order 12866
Under Executive Order 12866 (58 FR 51735, October 4, 1993), EPA
must determine whether the regulatory action is ``significant'' and
therefore subject to review by the Office of Management and Budget
(OMB), and the requirements of the Executive Order. The Executive Order
defines ``significant regulatory action'' as one that is likely to
result in a rule that may:
(1) Have an annual effect on the economy of $100 million or more or
adversely affect in a material way the economy, a sector of the
economy, productivity, competition, jobs, the environment, public
health or safety, or State, local, or tribal governments or
communities;
(2) Create a serious inconsistency or otherwise interfere with an
action taken or planned by another agency;
(3) Materially alter the budgetary impact of entitlements, grants,
user fees, or loan programs, or the rights and obligation of recipients
thereof; or
(4) Raise novel legal or policy issues arising out of legal
mandates, the President's priorities, or the principles set forth in
the Executive Order.
Because the projected annual costs (including monitoring) for this
NESHAP are $27 million a regulatory impact analysis has not been
prepared. However this action is considered a ``significant regulatory
action'' within the meaning of Executive Order 12866, and the proposed
regulation presented in this notice was submitted to the OMB for
review. Any written comments are included in the docket listed at the
beginning of today's notice under ADDRESSES. The docket is available
for public inspection at the EPA's Air Docket Section, which is listed
in the ADDRESSES section of this preamble.
D. Enhancing the Intergovernmental Partnership Under Executive Order
12875
In compliance with Executive Order 12875, EPA has involved State
and local regulatory experts in the development of this proposed rule.
One tribal government and one State government is believed to be
affected by this proposed rule. Local governments, and State
governments other than the one State which operates a portland cement
plant are not directly impacted by the rule, i.e., they are not
required to purchase control systems to meet the requirements of the
rule. However, they will be required to implement the rule; e.g.,
incorporate the rule into permits and enforce the rule. They will
collect permit fees that will be used to offset the burden of
implementing the rule. Comments have been solicited from States and
from local air pollution control agency representatives and these
comments have been carefully considered in the rule development
process. In addition, all States are encouraged to comment on this
proposed rule during the public comment period, and the EPA intends to
fully consider these comments in the development of the final rule.
E. Unfunded Mandates Reform Act
Section 202 of the Unfunded Mandates Reform Act of 1995 (UMRA),
signed into law on March 22, 1995 (109
[[Page 14209]]
Stat. 48), requires that the Agency prepare a budgetary impact
statement before promulgating a rule that includes a Federal mandate
that may result in expenditure by State, local, and tribal governments,
in aggregate, or by the private sector, of $100 million or more in any
one year. Section 203 requires the Agency to establish a plan for
obtaining input from and informing, educating, and advising any small
governments that may be significantly or uniquely affected by the rule.
Under section 205 of the UMRA, the Agency must identify and
consider a reasonable number of regulatory alternatives before
promulgating a rule for which a budgetary impact statement must be
prepared. The Agency must select from those alternatives the least
costly, most cost-effective, or least burdensome alternative for State,
local, and tribal governments and the private sector that achieves the
objectives of the rule, unless the Agency explains why this alternative
is not selected or unless the selection of this alternative is
inconsistent with law.
Because this proposed rule, if promulgated, is estimated to result
in the expenditure by State, local, and tribal governments or the
private sector of less than $100 million in any one year, the Agency
has not prepared a budgetary impact statement or specifically addressed
the selection of the least costly, most cost-effective, or least
burdensome alternative. Because small governments will not be
significantly or uniquely affected by this rule, the Agency is not
required to develop a plan with regard to small governments. Therefore,
the requirements of the UMRA do not apply to this action.
F. Regulatory Flexibility Act
Under section 605 of the Regulatory Flexibility Act of 1980, 5
U.S.C. 601 et seq., Federal agencies are required to assess the
economic impact of Federal regulations on small entities. The
Regulatory Flexibility Act specifies that Federal agencies must prepare
an initial Regulatory Flexibility Analysis (RFA) if a proposed
regulation will have a significant economic impact on a substantial
number of small entities. For the purposes of the Agency's
implementation of the Act, the EPA's guidelines define a ``substantial
number'' as 100 or more firms.
The manufacture of portland cement is covered by SIC code 3241 for
hydraulic cements. According to Small Business Administration size
standards, firms owning portland cement plants are categorized as small
if the total number of employees at the firm is less than 750.
Otherwise the firm is classified as large. A total of 7 firms are
categorized as small, while the remaining 37 firms are large. Because a
substantial number of small firms are not affected, and the EPA does
not project a significant impact on small firms, the rule does not
require an RFA.
I certify that the rule will not have a significant economic impact
on a substantial number of small entities. This is because the rule has
a control cost share of revenue of less than one percent for all of the
seven cement plants which are considered small entities. [Refer to
section IV.H. (Economic Impacts) for more details on the cost and
estimated price increases.]
Although the rule will not have a significant impact on a
substantial number of small entities, nevertheless the Agency has
worked with portland cement small entities throughout the rulemaking
process. Meetings were held on a regular basis with the Portland Cement
Association (PCA) and industry representatives, including both small
and large firms, to discuss the development of the rule, exchange
information and data, solicit comments on draft rule requirements, and
provide a list of the small firms. In addition, some cement industry
representatives formed a group called the ``Small Cement Company MACT
Coalition'', which was represented by counsel during meetings held with
the PCA and industry representatives during the later stages of the
proposal development process. Finally, the Small Cement Company MACT
Coalition designated the PCA as its representative in future meetings
with the EPA concerning the rulemaking for the portland cement
industry.
To minimize adverse impacts on the small entities, the Agency has
proposed controls at the MACT-floor level and tailored the requirements
to permit less costly testing and monitoring by using surrogates for
HAP emissions and provided choice in methods of demonstrating
compliance. The Agency has also tried to make the rule ``user
friendly,'' with language that is easy to understand by all of the
regulated community. To minimize capital availability problems EPA also
proposes to allow affected firms up to 3 years from the effective date
of the final rule to comply. An extra year may be granted by the
Administrator or delegated regulatory authority if necessary to install
controls.
G. Paperwork Reduction Act
The information collection requirements in this proposed rule have
been submitted for approval to OMB under the requirements of the
Paperwork Reduction Act, 44 U.S.C. 3501 et seq. An Information
Collection Request (ICR) document has been prepared by EPA (ICR No.
1801.01), and a copy may be obtained from Sandy Farmer, OPPE Regulatory
Information Division, U.S. Environmental Protection Agency (2137), 401
M Street SW., Washington, DC 20460, or by calling (202) 260-2740.
The proposed information requirements include the notification,
recordkeeping, and reporting requirements of the NESHAP general
provisions (40 CFR part 63, subpart A), authorized under section 114 of
the Act, which are mandatory for all owners or operators subject to
national emission standards. All information submitted to EPA for which
a claim of confidentiality is made is safeguarded according to Agency
policies in 40 CFR part 2, subpart B. The proposed rule does not
require any notifications or reports beyond those required by the
general provisions. These information requirements are necessary to
determine compliance with the standard.
The annual public reporting and recordkeeping burden for this
collection is estimated at 77,000 labor hours per year at a total
annual cost of $2,470,000 over the three-year period. This corresponds
to an estimated burden of approximately 2000 hours per year for an
estimated 39 respondents. This estimate includes performance tests and
reports (with repeat tests where needed); one-time preparation of a
startup, shutdown, and malfunction plan with semiannual reports of any
event where the procedures in the plan were not followed; semiannual
excess emissions reports; notifications; and recordkeeping. Total
annualized capital costs associated with monitoring requirements over
the three-year period of the ICR is estimated at $194,000; this
estimate includes the capital and startup costs associated with
installation of required continuous monitoring equipment for those
affected subject to the standard. The total operation and maintenance
cost is estimated at $191,000 per year.
Burden means the total time, effort, or financial resources
expended by persons to generate, maintain, retain, or disclose or
provide information to or for a Federal agency. This includes the time
needed to review instructions; develop, acquire, install, and utilize
technology and systems for the purpose of collecting, validating, and
verifying information; processing and maintaining information, and
disclosing and providing information; adjust the existing ways to
comply with any
[[Page 14210]]
previously applicable instructions and requirements; train personnel to
respond to a collection of information; search existing data sources;
complete and review the collection of information; and transmit or
otherwise disclose the information.
An Agency may not conduct or sponsor, and a person is not required
to respond to a collection of information unless it displays a
currently valid OMB control number. The OMB control numbers for EPA's
regulations are listed in 40 CFR part 9 and 48 CFR chapter 15.
Send comments on the Agency's need for this information, the
accuracy of the provided burden estimates, and any suggested methods
for minimizing respondent burden, including through the use of
automated collection techniques to the Director, OPPE Regulatory
Information Division; U.S. Environmental Protection Agency (2137), 401
M Street SW., Washington, DC 20460; and to the Office of Information
and Regulatory Affairs, Office of Management and Budget, 725 17th
Street, NW, Washington, D.C. 20503, marked ``Attention: Desk Officer
for EPA.'' Include the ICR number in any correspondence. Since OMB is
required to make a decision concerning the ICR between 30 and 60 days
after March 24, 1998, a comment to OMB is best assured of having its
full effect if OMB receives it by April 23, 1998. The final rule will
respond to any OMB or public comments on the information collection
requirements contained in this proposal.
H. Clean Air Act
In accordance with section 117 of the Act, publication of this
proposal was preceded by consultation with appropriate advisory
committees, independent experts, and Federal departments and agencies.
This regulation will be reviewed eight years from the date of
promulgation. This review will include an assessment of such factors as
evaluation of the residual health risks, any overlap with other
programs, the existence of alternative methods, enforceability,
improvements in emission control technology and health data, and the
recordkeeping and reporting requirements.
List of Subjects in 40 CFR Part 63
Environmental protection, Air pollution control, Hazardous
substances, Portland cement manufacturing, Reporting and recordkeeping
requirements.
Dated: March 9, 1998.
Carol M. Browner,
Administrator.
For the reasons set out in the preamble, part 63 of title 40,
chapter 1 of the Code of Federal Regulations is proposed to be amended
as follows:
PART 63--NATIONAL EMISSION STANDARDS FOR HAZARDOUS AIR POLLUTANTS
FOR SOURCE CATEGORIES
1. The authority citation for part 63 continues to read as follows:
Authority: Secs. 101, 112, 114, 116, 183(f) and 301 of the Clean
Air Act as amended (42 U.S.C. et seq).
2. Part 63 is amended by adding a new subpart LLL consisting of
Secs. 63.1340 through 63.1359 to read as follows:
Subpart LLL--National Emission Standards for the Portland Cement
Manufacturing Industry
Sec.
63.1340 Applicability and designation of affected sources.
63.1341 Definitions.
63.1342 Standards: General.
63.1343 Standards for kilns and in-line kiln/raw mills.
63.1344 Standards for clinker coolers.
63.1345 Standards for new and reconstructed raw material dryers.
63.1346 Standards for affected sources other than kilns, in-line
kiln raw mills, clinker coolers, and new and reconstructed raw
material dryers.
63.1347 Compliance dates.
63.1348 Initial compliance demonstration.
63.1349 Monitoring requirements.
63.1350 Additional test methods.
63.1351 Notification requirements.
63.1352 Reporting requirements.
63.1353 Recordkeeping requirements.
63.1354 Delegation of authority.
63.1355-63.1359 [Reserved]
Table 1 to Subpart LLL--Applicability of General Provisions
Subpart LLL--National Emission Standards for the Portland Cement
Manufacturing Industry
Sec. 63.1340 Applicability and designation of affected sources.
(a) Except as specified in paragraphs (b) and (c) of this section,
the provisions of this subpart apply to each new and existing portland
cement plant which is a major source or an area source as defined in
Sec. 63.2 of this part.
(b) The affected sources subject to this subpart are:
(1) Each kiln and each in-line kiln/raw mill at any major or area
source, including alkali bypasses, except for kilns and in-line kiln/
raw mills that burn hazardous waste and are subject to and regulated
under subpart EEE of this part.1
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\1\ The EPA proposed regulations for subpart EEE of 40 CFR part
63 on April 19, 1996 at 61 FR 17358.
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(2) Each clinker cooler at any portland cement plant which is a
major source;
(3) Each raw mill at any portland cement plant which is a major
source;
(4) Each finish mill at any portland cement plant which is a major
source;
(5) Each raw material dryer at any portland cement plant which is a
major source;
(6) Each raw material, clinker, or finished product storage bin at
any portland cement plant which is a major source;
(7) Each conveying system transfer point at any portland cement
plant which is a major source;
(8) Each bagging system at any portland cement plant which is a
major source; and
(9) Each bulk loading or unloading system at any portland cement
plant which is a major source.
(c) For portland cement plants with on-site nonmetallic mineral
processing facilities, the first affected source in the sequence of
materials handling operations subject to this subpart is the raw
material storage, which is just prior to the raw mill. The primary and
secondary crushers and any other equipment of the on-site nonmetallic
mineral processing plant which precedes the raw material storage are
not subject to this subpart. Furthermore, the first conveyor transfer
point subject to this subpart is the transfer point associated with the
conveyor transferring material from the raw material storage to the raw
mill.
(d) The owner or operator of any affected source subject to the
provisions of this subpart is subject to title V permitting
requirements.
Sec. 63.1341 Definitions.
All terms used in this subpart that are not defined below have the
meaning given to them in the CAA and in subpart A of this part.
Alkali bypass means a duct between the feed end of the kiln and the
preheater tower through which a portion of the kiln exit gas stream is
withdrawn and quickly cooled by air or water to avoid excessive buildup
of alkali and sulfur on the raw feed.
Bag leak detection system means a monitoring system for a fabric
filter that identifies an increase in particulate emissions resulting
from a broken filter bag or other malfunction and sounds an alarm.
Bagging system means the equipment which fills bags with portland
cement.
[[Page 14211]]
Clinker cooler means equipment into which clinker product leaving
the kiln is placed to be cooled by air supplied by a forced draft or
natural draft supply system.
Conveying system means a device for transporting materials from one
piece of equipment or location to another location within a facility.
Conveying systems include but are not limited to the following:
feeders, belt conveyors, bucket elevators and pneumatic systems.
Conveying system transfer point means a point where any material
including but not limited to feed material, fuel, clinker or product,
is transferred to or from a conveying system, or between separate parts
of a conveying system.
Dioxins and furans (D/F) means
tetra-, penta-, hexa-, hepta-, and octa-chlorinated dibenzo dioxins and
furans.
Facility means all contiguous or adjoining property that is under
common ownership or control, including properties that are separated
only by a road or other public right-of-way.
Feed means the prepared and mixed materials, which include but are
not limited to materials such as limestone, clay, shale, sand, iron
ore, mill scale, and flyash, that are fed to the kiln and become part
of the clinker product. Feed does not include the fuels used in the
kiln to produce heat to form the clinker product.
Finish mill means a roll crusher, ball and tube mill or other size
reduction equipment used to grind clinker to a fine powder. Gypsum and
other materials may be added to and blended with clinker in a finish
mill. The finish mill also includes the air separator associated with
the finish mill.
Hazardous waste is defined in Sec. 261.3 of this chapter.
In-line kiln/raw mill means a system in a portland cement
production process where a dry kiln system is integrated with the raw
mill so that all or a portion of the kiln exhaust gases are used to
perform the drying operation of the raw mill, with no auxiliary heat
source used. In this system the kiln is capable of operating without
the raw mill operating, but the raw mill cannot operate without the
kiln gases, and consequently, the raw mill does not generate a separate
exhaust gas stream.
Kiln means a device, including any associated preheater or
precalciner devices, that produces clinker by heating limestone and
other materials for subsequent production of cement.
Monovent means an exhaust configuration of a building or emission
control device (e. g. positive pressure fabric filter) that extends the
length of the structure and has a width very small in relation to its
length (i.e., length to width ratio is typically greater than 5:1). The
exhaust may be an open vent with or without a roof, louvered vents, or
a combination of such features.
Portland cement plant means any facility manufacturing portland
cement.
Raw material dryer means an impact dryer, drum dryer, paddle-
equipped rapid dryer, air separator, or other equipment used to reduce
the moisture content of feed materials.
Raw mill means a ball and tube mill, vertical roller mill or other
size reduction equipment, that is not part of an in-line kiln/raw mill,
used to grind feed to the appropriate size. Moisture may be added or
removed from the feed during the grinding operation. If the raw mill is
used to remove moisture from feed materials, it is also, by definition,
a raw material dryer. The raw mill also includes the air separator
associated with the raw mill.
TEO means the international method of expressing toxicity
equivalents for dioxins and furans as defined in U.S. EPA, Interim
Procedures for Estimating Risks Associated with Exposures to Mixtures
of Chlorinated Dibenzo-p-dioxins and -dibenzofurans (CDDs and CDFs) and
1989 Update, March 1989.
Sec. 63.1342 Standards: General.
Table 1 to this subpart provides cross references to the 40 CFR
part 63, subpart A, general provisions, indicating the applicability of
the general provisions requirements to subpart LLL.
Sec. 63.1343 Standards for kilns and in-line kiln/raw mills.
(a) The provisions in this section apply to each kiln, each in-line
kiln/raw mill, and any alkali bypass associated with that kiln or in-
line kiln/raw mill.
(b) No owner or operator of an existing kiln or in-line kiln/raw
mill at a facility that is a major source subject to the provisions of
this subpart shall cause to be discharged into the atmosphere from
these affected sources, any gases which:
(1) Contain particulate matter in excess of 0.15 kg per Mg (0.30 lb
per ton) of feed (dry basis) to the kiln. When there is an alkali
bypass associated with a kiln or in-line kiln/raw mill, the combined
particulate matter emissions from the kiln or in-line kiln/raw mill and
the alkali bypass are subject to this emission limit.
(2) Exhibit opacity greater than 20 percent.
(3) Contain D/F in excess of
(i) 0.20 ng per dscm (8.7 x 10-11 gr per dscf)(TEQ)
corrected to seven percent oxygen; or
(ii) 0.40 ng per dscm (1.7 x 10-10 gr per dscf)(TEQ)
corrected to seven percent oxygen, when the temperature at the inlet to
the particulate matter air pollution control device is 204 deg.C
(400 deg.(F) or less.
(c) No owner or operator that commences construction of a new kiln
or new inline kiln/raw mill, or commences reconstruction of a kiln or
in-line kiln/raw mill at a facility which is a major source subject to
the provisions of this subpart shall cause to be discharged into the
atmosphere from these affected sources any gases which:
(1) Contain particulate matter in excess of 0.15 kg per Mg (0.30 lb
per ton) of feed (dry basis) to the kiln. When there is an alkali
bypass associated with a kiln or in-line kiln/raw mill, the combined
particulate matter emissions from the kiln or in-line kiln/raw mill and
the bypass stack are subject to this emission limit.
(2) Exhibit opacity greater than 20 percent.
(3) Contain D/F in excess of
(i) 0.20 ng per dscm (8.7 x 10-11 gr per dscf) (TEQ)
corrected to seven percent oxygen; or
(ii) 0.40 ng per dscm (1.7 x 10-10 gr per dscf) (TEQ)
corrected to seven percent oxygen, when the temperature at the inlet to
the particulate matter air pollution control device is 204 deg.C (400
deg.F) or less.
(4) Contain total hydrocarbon (THC), from the main exhaust of the
kiln or in-line kiln/raw mill, in excess of 50 ppmvd as propane,
corrected to seven percent oxygen.
(d) No owner or operator of a new or existing kiln or in-line kiln/
raw mill at a facility that is an area source subject to the provisions
of this subpart shall cause to be discharged into the atmosphere from
these affected sources any gases which contain D/F in excess of:
(1) 0.20 ng per dscm (8.7 x 10-11 gr per dscf) (TEQ)
corrected to seven percent oxygen; or
(2) 0.40 ng per dscm (1.7 x 10-10 gr per dscf) (TEQ)
corrected to seven percent oxygen, when the temperature at the inlet to
the particulate matter air pollution control device is 204 deg.C (400
deg.F) or less.
Sec. 63.1344 Standards for clinker coolers.
(a) No owner or operator of a new or existing clinker cooler at a
facility which is a major source subject to the provisions of this
subpart shall cause to be discharged into the atmosphere from the
clinker cooler any gases which:
(1) Contain particulate matter in excess of 0.050 kg per Mg (0.10
lb per ton) of feed (dry basis) to the kiln.
[[Page 14212]]
(2) Exhibit opacity greater than ten percent.
(b) [Reserved]
Sec. 63.1345 Standards for new and reconstructed raw material dryers.
(a) No owner or operator of a new or reconstructed raw material
dryer at a facility which is a major source subject to this subpart
shall cause to be discharged into the atmosphere from the new or
reconstructed raw material dryer any gases which:
(1) Contain THC in excess of 50 ppmvd, reported as propane,
corrected to seven percent oxygen.
(2) Exhibit opacity greater than ten percent.
(b) [Reserved]
Sec. 63.1346 Standards for affected sources other than kilns, in-line
kiln/raw mills, clinker coolers, and new and reconstructed raw material
dryers.
The owner or operator of each new or existing raw mill; finish
mill; raw material, clinker, or finished product storage bin; conveying
system transfer point; bagging system; and bulk loading or unloading
system; and each existing raw material dryer, at a facility which is a
major source subject to the provisions of this subpart shall not cause
to be discharged any gases from these affected sources which exhibit
opacity in excess of ten percent.
Sec. 63.1347 Compliance dates.
(a) The compliance date for an owner or operator of an existing
affected source subject to the provisions of this subpart is no later
than 36 months after publication of the final rule.
(b) The compliance date for an owner or operator of an affected
source subject to the provisions of this subpart that commences new
construction or reconstruction after March 24, 1998 is the date of
publication of the final rule or immediately upon startup of
operations, whichever is later.
Sec. 63.1348 Initial compliance demonstration.
(a) The owner or operator of an affected source subject to this
subpart shall demonstrate initial compliance with the emission limits
of Secs. 63.1343-63.1346 using the test methods and procedures in
paragraph (b) of this section and Sec. 63.7. Performance test results
shall be documented in complete test reports that contain the
information required by paragraphs (a)(1) through (a)(10) of this
section, as well as all other relevant information. The plan to be
followed during testing shall be made available to the Administrator
prior to testing, if requested.
(1) A brief description of the process and the air pollution
control system;
(2) Sampling location description(s);
(3) A description of sampling and analytical procedures and any
modifications to standard procedures;
(4) Test results;
(5) Quality assurance procedures and results;
(6) Records of operating conditions during the test, preparation of
standards, and calibration procedures;
(7) Raw data sheets for field sampling and field and laboratory
analyses;
(8) Documentation of calculations;
(9) All data recorded and used to establish parameters for
compliance monitoring; and
(10) Any other information required by the test method.
(b) Performance tests to demonstrate initial compliance with this
subpart shall be conducted as specified in paragraphs (b)(1) through
(b)(5) of this section.
(1) The owner or operator of a kiln subject to limitations on
particulate matter emissions shall demonstrate initial compliance by
conducting a performance test as specified in paragraphs (b)(1)(i)
through (b)(1)(iv) of this section. The owner or operator of an in-line
kiln/raw mill shall demonstrate initial compliance by conducting
separate performance tests as specified in paragraphs (b)(1)(i) through
(b)(1)(iv) of this section while the raw mill of the in-line kiln/raw
mill is under normal operating conditions and while the raw mill of the
in-line kiln/raw mill is not operating. The owner or operator of a
clinker cooler subject to limitations on particulate matter emissions
shall demonstrate initial compliance by conducting a performance test
as specified in paragraphs (b)(1)(i) through (b)(1)(iii) of this
section. The opacity exhibited during the period of the Method 5
performance tests required by paragraph (b)(1)(i) of this section shall
be determined as required in paragraphs (b)(1)(v) through (vi) of this
section.
(i) EPA Method 5 of appendix A to part 60 of this chapter shall be
used to determine PM emissions. Each performance test shall consist of
three separate runs under the conditions that exist when the affected
source is operating at the highest load or capacity level reasonably
expected to occur. Each run shall be conducted for at least one hour,
and the minimum sample volume shall be 0.85 dscm (30 dscf). The average
of the three runs shall be used to determine compliance. A
determination of the particulate matter collected in the impingers
(``back half'') of the Method 5 particulate sampling train is not
required.
(ii) Suitable methods shall be used to determine the kiln or inline
kiln/raw mill feed rate, except for fuels, for each run.
(iii) The emission rate, E, of PM shall be computed for each run
using equation 1:
E = (cs Qsd) / P
Where:
E = emission rate of particulate matter, kg/Mg of kiln feed.
cs = concentration of PM, kg/dscm.
Qsd = volumetric flow rate of effluent gas, dscm/hr.
P = total kiln feed (dry basis), Mg/hr.
(iv) When there is an alkali bypass associated with a kiln or in-
line kiln/raw mill, the main exhaust and alkali bypass of the kiln or
in-line kiln/raw mill shall be tested simultaneously and the combined
emission rate of particulate matter from the kiln or in-line kiln/raw
mill and alkali bypass shall be computed for each run using equation 2,
Ec = (cskQsdk +
csbQsdb)/P
Where:
Ec = the combined emission rate of particulate matter from
the kiln or in-line kiln/raw mill and bypass stack, kg/Mg of kiln feed,
csk = concentration of particulate matter in the kiln or in-
line kiln/raw mill effluent, kg/dscm,
Qsdk = volumetric flow rate of kiln or in-line kiln/raw mill
effluent, dscm/hr,
csb = concentration of particulate matter in the alkali
bypass gas, kg/dscm,
Qsdb = volumetric flow rate of alkali bypass gas, dscm/hr,
and P = total kiln feed (dry basis), Mg/hr.
(v) Except as provided in paragraph (b)(1)(vi) of this section the
opacity exhibited during the period of the Method 5 performance tests
required by paragraph (b)(1)(i) of this section shall be determined
through the use of a continuous opacity monitor (COM). The maximum six-
minute average opacity during the three Method 5 test runs shall be
determined during each Method 5 test run, and used to demonstrate
initial compliance with the applicable opacity limits of
Secs. 63.1343(b)(2), 63.1343(c)(2), or 63.1344(a)(2) of this subpart.
(vi) Each owner or operator of a kiln, in-line kiln/raw mill, or
clinker cooler subject to the provisions of this subpart using a fabric
filter with multiple stacks or an electrostatic precipitator with
multiple stacks may, in lieu of installing the continuous opacity
monitoring system required by paragraph (b)(1)(v) of this section,
conduct an opacity test in accordance with Method 9 of appendix A to
part 60 of this chapter
[[Page 14213]]
during each Method 5 performance test required by paragraph (b)(1)(i)
of this section. If the control device exhausts through a monovent, or
if the use of a COM in accordance with the installation specifications
of Performance Specification 1 (PS-1) of appendix B to part 60 of this
chapter is not feasible, a test shall be conducted in accordance with
Method 9 of appendix A to part 60 of this chapter during each Method 5
performance test required by paragraph (b)(1)(i) of this section. The
maximum six-minute average opacity shall be determined during the three
Method 5 test runs, and used to demonstrate initial compliance with the
applicable opacity limits of Secs. 63.1343(b)(2), 63.1343(c)(2), or
63.1344(a)(2) of this subpart.
(2) The owner or operator of a raw mill or finish mill subject to
limitations on opacity under this subpart shall demonstrate initial
compliance with the raw mill and finish mill opacity limit by
conducting a performance test in accordance with Method 9 of appendix A
to part 60 of this chapter. The performance test shall be conducted
under the conditions that exist when the affected source is operating
at the highest load or capacity level reasonably expected to occur. The
maximum six-minute average opacity exhibited during the performance
test shall be used to determine whether the affected source is in
initial compliance with the standard. The duration of the Method 9
performance test shall be 3-hours (30 6-minute averages), except that
the duration of the Method 9 performance test may be reduced to 1-hour
if the conditions of paragraphs (b)(2)(i) through (ii) of the section
apply:
(i) There are no individual readings greater than 10 percent
opacity;
(ii) There are no more than three readings of 10 percent for the
first 1-hour period.
(3) The owner or operator of any affected source subject to
limitations on opacity under this subpart that is not subject to
Sec. 63.1348(b)(1) through (2) shall demonstrate initial compliance
with the affected source opacity limit by conducting a test in
accordance with Method 9 of appendix A to part 60 of this chapter. The
maximum six-minute average opacity exhibited during the test period
shall be used to determine whether the affected source is in initial
compliance with the standard. The duration of the Method 9 performance
test shall be 3-hours (30 6-minute averages), except that the duration
of the Method 9 performance test may be reduced to 1-hour if the
conditions of paragraphs (b)(3)(i) through (ii) of the section apply:
(i) There are no individual readings greater than 10 percent
opacity;
(ii) There are no more than three readings of 10 percent for the
first 1-hour period.
(4) The owner or operator of an affected source subject to
limitations on D/F emissions shall demonstrate initial compliance with
the D/F emission limit by conducting a performance test using Method 23
of appendix A to part 60 of this chapter. The owner or operator of an
in-line kiln/raw mill shall demonstrate initial compliance by
conducting separate performance tests while the raw mill of the in-line
kiln/raw mill is under normal operating conditions and while the raw
mill of the in-line kiln/raw mill is not operating. The owner or
operator of a kiln or in-line kiln/raw mill equipped with an alkali
bypass shall conduct simultaneous performance tests of the kiln or in-
line kiln/raw mill exhaust and the alkali bypass, however the owner or
operator of an in-line kiln/raw mill is not required to conduct a
performance test of the alkali bypass exhaust when the raw mill of the
in-line kiln/raw mill is not operating.
(i) Each performance test shall consist of three separate runs;
each run shall be conducted under the conditions that exist when the
affected source is operating at the highest load or capacity level
reasonably expected to occur. The duration of each run shall be at
least three hours and the sample volume for each run shall be at least
2.5 dscm (90 dscf). The arithmetic average concentration measured
during each of the three runs shall be used to determine compliance.
(ii) The temperature at the inlet to the kiln or in-line kiln/raw
mill PM APCD, and where applicable, the temperature at the inlet to the
alkali bypass PM APCD, must be continuously recorded during the period
of the Method 23 test, and the continuous temperature record(s) must be
included in the performance test report. The arithmetic average
temperature must be determined for each run. The arithmetic average of
the averages for the three runs must be calculated and included in the
performance test report and will determine the applicable temperature
limit in accordance with Sec. 63.1349(d)(4) of this subpart.
(iii) If carbon injection is used for D/F control, the carbon
injection rate must be measured during the period of each run. The
average carbon injection rate measured for the three runs shall be
determined and included in the test report, and shall be used for
compliance purposes in accordance with Sec. 63.1349(e) of this subpart.
(5) The owner or operator of an affected source subject to
limitations on emissions of THC shall demonstrate initial compliance
with the THC limit by operating a continuous emission monitor in
accordance with Performance Specification 8A of appendix B to part 60
of this chapter.2 The duration of the performance test shall
be three hours, and the average THC concentration during the three hour
performance test shall be calculated. The owner or operator of an in-
line kiln/raw mill shall demonstrate initial compliance by conducting
separate performance tests while the raw mill of the in-line kiln/raw
mill is under normal operating conditions and while the raw mill of the
in-line kiln/raw mill is not operating.
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\2\ The EPA proposed amendments to appendix B to 40 CFR part 60
on April 19, 1996 at 61 FR 17358.
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(c) Performance tests required under paragraphs (b)(1) through (4)
of this section shall be repeated every five years, except that the
owner or operator of a kiln, in-line kiln/raw mill or clinker cooler is
not required to repeat the initial performance test of opacity.
Sec. 63.1349 Monitoring requirements.
(a) The owner or operator of a kiln or in-line kiln/raw mill shall
demonstrate continuous compliance with the opacity standard at each
point where emissions are vented from these affected sources including
alkali bypasses in accordance with paragraphs (a)(1) through (a)(5) of
this section.
(1) Except as provided in paragraph (a)(2) of this section, the
owner or operator shall install, calibrate, maintain, and continuously
operate a continuous opacity monitor (COM) located at the outlet of the
PM control device to continuously monitor the opacity. The COM shall be
installed, maintained, calibrated, and operated as required by subpart
A, general provisions of this part, and according to PS-1 of appendix B
to part 60 of this chapter.
(2) The owner or operator of a kiln or in-line kiln/raw mill
subject to the provisions of this subpart using a fabric filter with
multiple stacks or an electrostatic precipitator with multiple stacks
may, in lieu of installing the continuous opacity monitoring system
required by paragraph (a)(1) of this section, monitor opacity in
accordance with paragraphs (a)(2)(i) through (ii) of this section. If
the control device exhausts through a monovent, or if the use of a COM
in accordance with the installation specifications of PS-1 of appendix
B to part 60 of this chapter is not feasible, the owner or operator
must
[[Page 14214]]
monitor opacity in accordance with paragraphs (a)(2)(i) through (ii) of
this section.
(i) Perform daily visual opacity observations of each stack in
accordance with the procedures of Method 9 of appendix A of part 60 of
this chapter. The duration of the Method 9 test shall be at least 30
minutes each day.
(ii) Use the Method 9 procedures to monitor and record the average
opacity for each six-minute period during the test.
(3) To remain in compliance, the opacity must be maintained such
that the average of the 6-minute average opacities for any 30-minute
period does not exceed 20 percent. If the average of the six-minute
average opacities for any 30-minute period exceeds 20 percent, this
shall constitute a violation of the standard.
(4) If the average opacity as determined in accordance with
paragraph (a)(1) of this section exceeds 15 percent for any ten
consecutive 30-minute periods, or if the average opacity as determined
in accordance with paragraphs (a)(2)(i) through (ii) of this section
exceeds 15 percent for any 30-minute period, the owner or operator
shall initiate a site-specific operating and maintenance plan within
one hour. The site-specific operating and maintenance plan shall be
developed in accordance with paragraph (g) of this section. Failure to
initiate the site-specific operating and maintenance plan within one
hour shall constitute a violation of the standard.
(5) If the average 30-minute opacity as determined in accordance
with paragraph (a)(1) of this section exceeds 15 percent for five
percent or more of the kiln operating time in any six-month reporting
period, or if the 30-minute average opacity reading as determined in
accordance with paragraphs (a)(2)(i) through (ii) of this section
exceeds 15 percent during five percent or more of the daily readings in
any six-month reporting period, the owner or operator shall notify the
permitting authority within 48 hours and shall develop and implement a
quality improvement plan (QIP) within 180 days. The QIP shall be
developed in accordance with paragraph (h) of this section. Failure to
notify the permitting authority within 48 hours shall constitute a
violation of the standard. Failure to develop and implement a QIP
within 180 days shall constitute a violation of the standard.
(b) The owner or operator of a clinker cooler shall demonstrate
continuous compliance with the opacity standard at each point where
emissions are vented from the clinker cooler in accordance with
paragraphs (b)(1) through (b)(3) of this section.
(1) Except as provided in paragraph (b)(2) of this section, the
owner or operator shall install, calibrate, maintain, and continuously
operate a COM located at the outlet of the clinker cooler PM control
device to continuously monitor the opacity. The COM shall be installed,
maintained, calibrated, and operated as required by subpart A, general
provisions of this part, and according to PS-1 of appendix B to part 60
of this chapter.
(2) The owner or operator of a clinker cooler subject to the
provisions of this subpart using a fabric filter with multiple stacks
or an electrostatic precipitator with multiple stacks may, in lieu of
installing the continuous opacity monitoring system required by
paragraph (b)(1) of this section, monitor opacity in accordance with
paragraphs (b)(2)(i) through (ii) of this section. If the control
device exhausts through a monovent, or if the use of a COM in
accordance with the installation specifications of PS-1 of appendix B
to part 60 of this chapter is not feasible, the owner or operator must
monitor opacity in accordance with paragraphs (b)(2)(i) through (ii) of
this section.
(i) Perform daily visual opacity observations of each stack in
accordance with the procedures of Method 9 of appendix A of part 60 of
this chapter. The duration of the Method 9 test shall be at least 30
minutes each day.
(ii) Use the Method 9 procedures to monitor and record the average
opacity for each six-minute period during the test.
(3) To remain in compliance, the opacity must be maintained such
that the average of the 6-minute average opacities for any 30-minute
period does not exceed 10 percent. If the average of the six-minute
average opacities for any 30-minute period exceeds 10 percent, this
shall constitute a violation of the standard.
(c) The owner or operator of a raw mill or finish mill shall
demonstrate continuous compliance with the opacity standard either by
conducting visual emissions observations in accordance with paragraph
(c)(1) of this section or through the use of a bag leak detection
system in accordance with paragraphs (c)(2)(i) through (vii) of this
section.
(1) An owner or operator may demonstrate compliance by performing
daily visual emissions observations in accordance with the procedures
of Method 22 of appendix A of part 60 of this chapter. The duration of
the Method 22 test shall be six-minutes. If no visual emissions are
observed at any time within the six-minute test, the source is in
compliance.
(2) An owner or operator may demonstrate compliance by installing,
calibrating, maintaining, and continuously operating a bag leak
detection system in accordance with paragraphs (c)(2)(i) through (vii)
of this section.
(i) The bag leak detection system must be capable of detecting PM
emissions at concentrations of 1.0 mg per actual cubic meter (0.00044
grains per actual cubic foot) and greater.
(ii) The bag leak detection system sensor must provide output of
relative or absolute PM emissions.
(iii) The bag leak detection system must be equipped with an alarm
system that will sound when an increase in PM emissions is detected.
(iv) For positive pressure baghouses, a bag leak detector must be
installed in each baghouse compartment. If a negative pressure or
induced air baghouse is used, the bag leak detector must be installed
downstream of the baghouse. Where multiple detectors are required (for
either type of baghouse), the system instrumentation and alarm may be
shared among detectors.
(v) The bag leak detection system shall be installed, operated,
calibrated, and maintained in a manner consistent with available
guidance from the U. S. Environmental Protection Agency or, in the
absence of such guidance, the manufacturer's written specifications and
recommendations.
(vi) Calibration of the system shall, at minimum, consist of
establishing the relative baseline output level by adjusting the
sensitivity and averaging period of the device and establishing the
alarm set points and the alarm delay time.
(vii) The owner or operator shall not adjust the sensitivity,
averaging period, alarm set points, or alarm delay time after the
initial performance test unless a subsequent performance test is
performed.
(3) If, in accordance with paragraph (c)(1) of this section visual
emissions are observed the owner or operator shall follow the
procedures of paragraphs (c)(3)(i) through (ii) of this section. If, in
accordance with paragraphs (c)(2)(i) through (vii) of this section, the
bag leak detection system alarm is triggered, the owner or operator
shall follow the procedure of paragraphs (c)(3)(i) of this section.
(i) Initiate, within one-hour, a site specific operating and
maintenance plan developed in accordance with paragraph (g) of this
section. If a site specific operating and maintenance plan is not
initiated within one hour, this
[[Page 14215]]
shall constitute a violation of the standard.
(ii) Conduct a visual opacity observation of each stack from which
visible emissions were observed in accordance with the procedures of
Method 9 of appendix A of part 60 of this chapter. The owner or
operator must begin the Method 9 test within 24 hours of the end of the
Method 22 test in which visible emissions were observed. The duration
of the Method 9 test shall be thirty-minutes. If the average of the
six-minute average opacities recorded during the Method 9 test exceeds
10 percent, this shall constitute a violation of the standard. If the
owner or operator fails to begin the Method 9 test within 24 hours of
the end of the Method 22 test in which visible emissions were observed,
this shall constitute a violation of the standard.
(d) The owner or operator of an affected source subject to a
limitation on D/F emissions shall comply with the following monitoring
requirements to demonstrate continuous compliance with the D/F emission
standard:
(1) The owner or operator shall install, calibrate, maintain, and
continuously operate a device to monitor and record the temperature of
the exhaust gases from the kiln, in-line kiln/raw mill and alkali
bypass, if applicable, at the inlet to the kiln, in-line kiln/raw mill
and/or alkali bypass PM control devices consistent with the
requirements for continuous monitoring systems in subpart A, general
provisions. The device shall have an accuracy of 2 degrees
Fahrenheit or 1 percent of the temperature measured in
degrees Fahrenheit.
(2) The owner or operator shall monitor and continuously record the
temperature of the exhaust gases from the kiln, in-line kiln/raw mill
and alkali bypass, if applicable, at the inlet to the kiln, in-line
kiln/raw mill and/or alkali bypass PM control device.
(3) To remain in compliance with the D/F emission limit, the owner
or operator of a kiln must maintain the temperature of the gas at the
inlet to the kiln PM control device and alkali bypass PM control
device, if applicable, such that the applicable temperature limits
specified in paragraph (d)(4) of this section are never exceeded for
any nine-hour block averaging period. If any nine-hour average
temperature exceeds these temperature limits, this shall constitute a
violation of the standard. To remain in compliance with the D/F
emission limit, the owner or operator of an in-line kiln/raw mill must
maintain the temperature of the gas at the inlet to the in-line kiln/
raw mill PM control device and in-line kiln/raw mill alkali bypass PM
control device, if applicable, such that,
(i) When the raw mill of the in-line kiln/raw mill is operating,
the applicable temperature limit(s) specified in paragraph (d)(4) of
this section and established during the performance test when the raw
mill was operating is (are) never exceeded for any nine-hour average.
If any nine-hour average temperature exceeds the applicable temperature
limit, this shall constitute a violation of the standard, and
(ii) When the raw mill of the in-line kiln/raw mill is not
operating, the applicable temperature limit for the main in-line kiln/
raw mill exhaust, specified in paragraph (d)(4) of this section and
established during the performance test when the raw mill was not
operating, is never exceeded for any nine-hour block averaging period.
If any nine-hour average temperature exceeds the applicable temperature
limit, this shall constitute a violation of the standard, and
(iii) If the in-line kiln/raw mill is equipped with an alkali
bypass, the applicable temperature limit for the alkali bypass,
specified in paragraph (d)(4) of this section and established during
the performance test when the raw mill was operating, is never exceeded
for any nine-hour block averaging period. If any nine-hour average
temperature exceeds the applicable temperature limit, this shall
constitute a violation of the standard.
(4) The temperature limit for affected sources meeting the limits
of Secs. 63.1343(b)(3)(ii), 63.1343(c)(3)(ii) and 63.1343(d)(2) of this
subpart is 204 degrees C (400 degrees F). The temperature limits(s) for
affected sources meeting the limits of Secs. 63.1343(b)(3)(i),
63.1343(c)(3)(i) and 63.1343(d)(1) is (are) determined according to
paragraphs (d)(4)(i) through (iii) of this section.
(i) Except as provided in paragraph (d)(4)(iii) of this section, if
the D/F emissions determined by the most recent performance test
conducted in accordance with Sec. 63.1348(b)(4) of this subpart do not
exceed 0.15 ng TEQ/dscm (6.5 x 10-11 gr/dscf), the
temperature limit(s) is (are) the average temperature(s) recorded
during the performance test plus five percent of the temperature
expressed in degrees Fahrenheit, or the average temperature(s) recorded
during the performance test plus 25 deg. F, whichever is lower.
(ii) Except as provided in paragraph (d)(4)(iii) of this section,
if the D/F emissions determined by the most recent performance test
conducted in accordance with Sec. 63.1348(b)(4) of this subpart is
(are) between 0.15 ng TEQ/dscm (6.5 x 10-11 gr TEQ/dscf)
and 0.20 ng TEQ/dscm (8.7 x 10-11 gr TEQ/dscf), the
temperature limit(s) is (are) the average temperature(s) recorded
during the performance test.
(iii) No temperature limit established under this section shall be
less than 204 deg.C (400 deg.F).
(5) The calibration of all thermocouples and other temperature
sensors shall be verified every three months.
(e) The owner or operator of an affected source subject to a
limitation on D/F emissions that employs carbon injection as an
emission control technique shall comply with the monitoring
requirements of paragraphs (d)(1) through (d)(5) and (e)(1) through
(e)(2) of this section to demonstrate continuous compliance with the D/
F emission standard:
(1) Measure the mass of carbon injected for every nine-hour period.
(2) If the carbon injection rate averaged over any nine-hour period
is less than the average of the carbon injection rates for the three
runs of the performance test conducted in accordance with
Sec. 63.1348(b)(4) of this subpart, this shall constitute a violation
of the standard.
(f) The owner or operator of an affected source subject to a
limitation on THC emissions under this subpart shall comply with the
monitoring requirements of paragraphs (f)(1) and (f)(2) of this section
to demonstrate continuous compliance with the THC emission standard:
(1) The owner or operator shall install, operate and maintain a THC
continuous emission monitoring system in accordance with Performance
Specification 8A, of appendix B to part 60 of this chapter 3
and comply with all of the requirements for continuous monitoring
systems found in subpart A, general provisions of this part.
---------------------------------------------------------------------------
\3\ Ibid.
---------------------------------------------------------------------------
(2) Any thirty-day block average THC concentration in any gas
discharged from a new or reconstructed raw material dryer, a new or
reconstructed kiln, or a new or reconstructed in-line kiln/raw mill,
exceeding 50 ppmvd, reported as propane, corrected to seven percent
oxygen, is a violation of the standard.
(g) The owner or operator of each portland cement plant shall
prepare for each kiln, in-line kiln raw mill, raw mill and finish mill
which is an affected source subject to the provisions of this subpart,
a written operations and maintenance plan. The plan shall be
[[Page 14216]]
submitted to the Administrator for review and approval as part of the
application for a part 70 permit and shall include the following
information:
(1) Procedures for proper operation and maintenance of the affected
source and APCDs in order to meet the emission limits of Sec. 63.1343
of this subpart for kilns and in-line kiln raw mills and Sec. 63.1346
of this subpart for raw mills and finish mills, and
(2) Corrective actions to be taken when required by paragraphs
(a)(4) or (c)(3)(i) of this section.
(h) If required under paragraph (a)(5) of this section, an owner or
operator shall implement a QIP in accordance with paragraphs (h)(1)
through (h)(4) of this section.
(1) A QIP shall be a written plan.
(2) An initial QIP shall include procedures that are adequate for
evaluating the control performance problems monitored under paragraph
(a)(5) of this section.
(3) Based on the results of the evaluation procedures, the QIP
shall be modified to include procedures for conducting one or more of
the actions described in paragraphs (h)(3)(i) through (v) of this
section:
(i) Improved preventive maintenance practices,
(ii) Process operation changes,
(iii) Appropriate improvements in control methods,
(iv) Other steps appropriate to correct control performance, and
(v) More frequent or improved monitoring in conjunction with one or
more steps under paragraphs (h)(3)(i) through (iv) of this section.
(4) The owner or operator shall act to develop and implement a QIP
as expeditiously as practicable but in no case shall the period for
completing implementation of the QIP exceed 180 days from the date on
which notice of the need to implement the QIP must be provided to the
permitting authority under paragraph (a)(5) of this section. If the
owner or operator determines that more than 180 days will be necessary
to complete the appropriate improvements, the owner or operator shall
notify the permitting authority and obtain a site-specific resolution
subject to the approval of the permitting authority. Where appropriate,
the QIP may rely on procedures and corrective actions specified in an
existing plan developed to satisfy a separate applicable requirement
(such as a startup, shutdown, and malfunction plan or an operations and
maintenance plan).
63.1350 Additional test methods.
(a) Owners or operators conducting tests to determine the rates of
emission of hydrogen chloride (HCl) from kilns, in-line kiln/raw mills
and associated bypass stacks at portland cement manufacturing
facilities, for use in applicability determinations under Sec. 63.1340
of this subpart are permitted to use Method 321 or Method 322 of
appendix A to this part.
(b) Owners or operators conducting tests to determine the rates of
emission of HCl from kilns, in-line kiln/raw mills and associated
bypass stacks at portland cement manufacturing facilities, for use in
applicability determinations under Sec. 63.1340 of this subpart are
permitted to use Method 26 of appendix A to part 60 of this chapter,
provided that the conditions of paragraphs (b)(1) through (b)(3) of
this section are met:
(1) Method 321 or Method 322 of appendix A to this part is used to
validate Method 26 of appendix A to part 60 of this chapter in
accordance with section 6.1 of Method 301 of appendix A to this part.
(2) If a dry kiln or in-line kiln/raw mill is tested by Method 26,
the Method 301 validation is conducted on a dry kiln or in-line kiln/
raw mill.
(3) If a wet kiln is tested by Method 26, the Method 301 validation
is conducted on a wet kiln.
(c) Owners or operators conducting tests to determine the rates of
emission of HCl from kilns, in-line kiln/raw mills and associated
bypass stacks at portland cement manufacturing facilities, for use in
applicability determinations under Sec. 63.1340 of this subpart are
permitted to use Method 26A of appendix A to part 60 of this chapter,
provided that the conditions of paragraphs (c)(1) through (c)(3) of
this section are met:
(1) Method 321 or Method 322 of appendix A to this part is used to
validate Method 26A of appendix A to part 60 of this chapter in
accordance with section 6.1 of Method 301 of appendix A to this part.
(2) If a dry kiln or in-line kiln/raw mill is tested by Method 26A,
the Method 301 validation is conducted on a dry kiln or in-line kiln/
raw mill.
(3) If a wet kiln is tested by Method 26A, the Method 301
validation is conducted on a wet kiln.
(d) Owners or operators conducting tests to determine the rates of
emission of specific organic HAP from raw material dryers, kilns and
in-line kiln/raw mills at portland cement manufacturing facilities, for
use in applicability determinations under Sec. 63.1340 of this subpart
are permitted to use Method 320 of appendix A to this part, or Method
18 of appendix A to part 60 of this chapter.
Sec. 63.1351 Notification requirements.
(a) The notification provisions of 40 CFR part 63, subpart A that
apply and those that do not apply to owners and operators of affected
sources subject to this subpart are listed in Table 1 of this subpart.
If any State requires a notice that contains all of the information
required in a notification listed in this section, the owner or
operator may send the Administrator a copy of the notice sent to the
State to satisfy the requirements of this section for that
notification.
(b) Each owner or operator subject to the requirements of this
subpart shall comply with the notification requirements in Sec. 63.9 of
this part as follows:
(1) Initial notifications as required by Sec. 63.9(b) through (d)
of this part. For the purposes of this subpart, a Title V or part 70
permit application may be used in lieu of the initial notification
required under Sec. 63.9(b), provided the same information is contained
in the permit application as required by Sec. 63.9(b), and the State to
which the permit application has been submitted has an approved
operating permit program under part 70 of this chapter and has received
delegation of authority from the EPA. Permit applications shall be
submitted by the same due dates as those specified for the initial
notification.
(2) Notification of performance tests, as required by Secs. 63.7
and 63.9(e) of this part.
(3) Notification of opacity and visible emission observations
required by Sec. 63.1348(b)(1) through (3) in accordance with
Secs. 63.6(h)(5) and 63.9(f) of this part.
(4) Notification, as required by Sec. 63.9(g) of this part, of the
date that the continuous emission monitor performance evaluation
required by Sec. 63.8(e) of this part is scheduled to begin.
(5) Notification of compliance status, as required by Sec. 63.9(h)
of this part.
(c) Each owner or operator subject to the requirements of this
subpart that is required to implement a QIP shall submit notifications
as follows:
(1) Notification, as required by Sec. 63.1349(a)(5) of this
subpart, of the requirement to implement a QIP.
(2) Notification, as required by Sec. 63.1349(h)(4) of this
subpart, if applicable, that more than 180 days will be required to
complete the appropriate improvements.
Sec. 63.1352 Reporting requirements.
(a) The reporting provisions of 40 CFR part 63, subpart A that
apply and those that do not apply to owners or operators
[[Page 14217]]
of affected sources subject to this subpart are listed in Table 1 of
this subpart. If any State requires a report that contains all of the
information required in a report listed in this section, the owner or
operator may send the Administrator a copy of the report sent to the
State to satisfy the requirements of this section for that report.
(b) The owner or operator of an affected source shall comply with
the reporting requirements specified in Sec. 63.10 of the general
provisions to part 63, subpart A as follows:
(1) As required by Sec. 63.10(d)(2) of this part, the owner or
operator shall report the results of performance tests as part of the
notification of compliance status.
(2) As required by Sec. 63.10(d)(3) of this part, the owner or
operator of an affected source shall report the opacity or visible
emission results from tests required by Sec. 63.1348(b)(1)-(3) of this
subpart along with the results of the performance test required under
Sec. 63.7 of this part.
(3) As required by Sec. 63.10(d)(4) of this part, the owner or
operator of an affected source who is required to submit progress
reports as a condition of receiving an extension of compliance under
Sec. 63.6(i) of this part shall submit such reports by the dates
specified in the written extension of compliance.
(4) As required by Sec. 63.10(d)(5) of this part, if actions taken
by an owner or operator during a startup, shutdown, or malfunction of
an affected source (including actions taken to correct a malfunction)
are consistent with the procedures specified in the source's startup,
shutdown, and malfunction plan specified in Sec. 63.6(e)(3) of this
part, the owner or operator shall state such information in a
semiannual report. Reports shall only be required if a startup,
shutdown, or malfunction occurred during the reporting period. The
startup, shutdown, and malfunction report may be submitted
simultaneously with the excess emissions and continuous monitoring
system performance reports; and
(5) Any time an action taken by an owner or operator during a
startup, shutdown, or malfunction (including actions taken to correct a
malfunction) is not consistent with the procedures in the startup,
shutdown, and malfunction plan, the owner or operator shall make an
immediate report of the actions taken for that event within 2 working
days, by telephone call or facsimile (FAX) transmission. The immediate
report shall be followed by a letter, certified by the owner or
operator or other responsible official, explaining the circumstances of
the event, the reasons for not following the startup, shutdown, and
malfunction plan, and whether any excess emissions and/or parameter
monitoring exceedances are believed to have occurred.
(6) As required by Sec. 63.10(e)(2) of this part, the owner or
operator shall submit a written report of the results of the
performance evaluation for the continuous monitoring system required by
Sec. 63.8(e) of this part. The owner or operator shall submit the
report simultaneously with the results of the performance test.
(7) As required by Sec. 63.10(e)(2) of this part, the owner or
operator of an affected source using a continuous opacity monitoring
system to determine opacity compliance during any performance test
required under Sec. 63.7 of this part and described in Sec. 63.6(d)(6)
of this part shall report the results of the continuous opacity
monitoring system performance evaluation conducted under Sec. 63.8(e)
of this part.
(8) As required by Sec. 63.10(e)(3) of this part, the owner or
operator of an affected source equipped with a continuous emission
monitor shall submit an excess emissions and continuous monitoring
system performance report for any event when the continuous monitoring
system data indicate the source is not in compliance with the
applicable emission limitation or operating parameter limit.
(9) The owner or operator shall submit a summary report
semiannually which contains the information specified in
Sec. 63.10(e)(3)(vi) of this part. In addition, the summary report
shall include:
(i) All exceedences of maximum control device inlet gas temperature
limits determined under Sec. 63.1349(d)(4) of this subpart,
(ii) All failures to calibrate thermocouples and other temperature
sensors as required under Sec. 63.1349(d)(5) of this subpart, and
(iii) All exceedences in carbon injection rate as required under
Sec. 63.1349(e)(2) of this subpart.
(10) If the total continuous monitoring system downtime for any CEM
or any continuous monitoring system (CMS) for the reporting period is
five percent or greater of the total operating time for the reporting
period, the owner or operator shall submit an excess emissions and
continuous monitoring system performance report along with the summary
report.
Sec. 63.1353 Recordkeeping requirements.
(a) The owner or operator shall maintain files of all information
(including all reports and notifications) required by this section
recorded in a form suitable and readily available for inspection and
review as required by Sec. 63.10(b)(1). The files shall be retained for
at least five years following the date of each occurrence, measurement,
maintenance, corrective action, report, or record. At a minimum, the
most recent two years of data shall be retained on site. The remaining
three years of data may be retained off site. The files may be
maintained on microfilm, on a computer, on floppy disks, on magnetic
tape, or on microfiche.
(b) The owner or operator shall maintain records for each affected
source as required by Sec. 63.10(b)(2) and (b)(3) of this part, and
(1) All documentation supporting initial notifications and
notifications of compliance status under Sec. 63.9 of this part.
(2) All records of applicability determination, including
supporting analyses, and
(3) If the owner or operator has been granted a waiver under
Sec. 63.8(f)(6) of this part, any information demonstrating whether a
source is meeting the requirements for a waiver of recordkeeping or
reporting requirements.
(c) In addition to the recordkeeping requirements in paragraph (b)
of this section, the owner or operator of an affected source equipped
with a continuous monitoring system shall maintain all records required
by Sec. 63.10(c) of this part.
(d) In addition to the recordkeeping requirements in paragraph (b)
of this section, the owner or operator of an affected source equipped
with a bag leak detection system shall maintain records of any bag leak
detection system alarm, including the date and time of the alarm and
the date and time that corrective action was initiated, with a brief
explanation of the cause of the alarm and the corrective action taken.
Sec. 63.1354 Delegation of authority.
(a) In delegating implementation and enforcement authority to a
State under subpart E of this part, the authorities contained in
paragraph (b) of this section shall be retained by the Administrator
and not transferred to a State.
(b) Authority which will not be delegated to States:
Sec. 63.1348(b), approval of alternate test methods for particulate
matter determination; approval of alternate test methods for opacity;
approval of alternate test methods for D/F; Sec. 63.1350, approval of
alternate test methods for Hcl.
Secs. 63.1355-63.1359 [Reserved]
[[Page 14218]]
Table 1 To Subpart LLL.--Applicability of General Provisions
----------------------------------------------------------------------------------------------------------------
General provisions citation Requirement Applies to subpart LLL Comment
----------------------------------------------------------------------------------------------------------------
63.1(a)(1)-(4)................ Applicability........ Yes
63.1(a)(5).................... ..................... No................................ [Reserved].
63.1(a)(6)-(a)(8)............. Applicability........ Yes
63.1(a)(9).................... ..................... No................................ [Reserved].
63.1(a)(10)-(14).............. Applicability........ Yes
63.1(b)(1).................... Initial Applicability No................................ Sec. 63.1340
Determination. specifies
applicability.
63.1(b)(2)-(3)................ Initial Applicability Yes
Determination.
63.1(c)(1).................... Applicability After Yes
Standard Established.
63.1(c)(2).................... Permit Requirements.. Yes............................... Area sources must
obtain Title V
permits.
63.1(c)(3).................... ..................... No................................ [Reserved].
63.1(c)(4)-(5)................ Extensions, Yes .....................
Notifications.
63.1(d)....................... ..................... No................................ [Reserved].
63.1(e)....................... Applicability of Yes
Permit Program.
63.2.......................... Definitions.......... Yes............................... Additional
definitions in Sec.
63.1341.
63.3(a)-(c)................... Units and Yes .....................
Abbreviations.
63.4(a)(1)-(a)(3)............. Prohibited Activities Yes .....................
63.4(a)(4).................... ..................... No................................ [Reserved].
63.4(a)(5).................... Compliance date...... Yes
63.4(b)-(c)................... Circumvention, Yes
Severability.
63.5(a)(1)-(2)................ Construction/ Yes
Reconstruction.
63.5(b)(1).................... Compliance Dates..... Yes
63.5(b)(2).................... ..................... No................................ [Reserved].
63.5(b)(3)-(6)................ Construction Yes
Approval,
Applicability.
63.5(c)....................... ..................... No................................ [Reserved].
63.5(d)(1)-(4)................ Approval of Yes
Construction/
Reconstruction.
63.5(e)....................... Approval of Yes
Construction/
Reconstruction.
63.5(f)(1)-(2)................ Approval of Yes .....................
Construction/
Reconstruction.
63.6(a)....................... Compliance for Yes
Standards and
Maintenance.
63.6(b)(1)-(5)................ Compliance Dates..... Yes
63.6(b)(6).................... ..................... No................................ [Reserved].
63.6(b)(7).................... Compliance Dates..... Yes
63.6(c)(1)-(2)................ Compliance Dates..... Yes
63.6(c)(3)-(c)(4)............. ..................... No................................ [Reserved].
63.6(c)(5).................... Compliance Dates..... Yes
63.6(d)....................... ..................... No................................ [Reserved].
63.6(e)(1)-(e)(2)............. Operation & Yes
Maintenance.
63.6(e)(3).................... Startup, Shutdown Yes
Malfunction Plan.
63.6(f)(1)-(3)................ Compliance with Yes
Emission Standards.
63.6(g)(1)-(g)(3)............. Alternative Standard. Yes
63.6(h)(1)-(2)................ Opacity/VE Standards. Yes
63.6(h)(3).................... ..................... No................................ Reserved
63.6(h)(4)-(h)(5)(i).......... Opacity/VE Standards. Yes
63.6(h)(5)(ii)-(iv)........... Opacity/VE Standards. No................................ Test duration
specified in Subpart
LLL
63.6(h)(6).................... Opacity/VE Standards. Yes
63.6(i)(1)-(i)(14)............ Extension of Yes
Compliance.
63.6(i)(15)................... ..................... No................................ [Reserved].
63.6(i)(16)................... Extension of Yes
Compliance.
63.6(j)....................... Exemption from Yes...............................
Compliance
63.7(a)(1)-(a)(3)............. Performance Testing Yes............................... Sec. 63.1348 has
Requirements. specific
requirements.
63.7(b)....................... Notification......... Yes
63.7(c)....................... Quality Assurance/ Yes
Test Plan.
63.7(d)....................... Testing Facilities... Yes
63.7(e)(1)-(4)................ Conduct of Tests..... Yes
63.7(f)....................... Alternative Test Yes
Method.
63.7(g)....................... Data Analysis........ Yes
63.7(h)....................... Waiver of Tests...... Yes
63.8(a)(1).................... Monitoring Yes
Requirements.
63.8(a)(2).................... Monitoring........... No................................ Sec. 63.1349
includes CEM
requirements.
63.8(a)(3).................... ..................... No................................ [Reserved].
63.8(a)(4).................... Monitoring........... No................................ Flares not
applicable.
63.8(b)(1)-(3)................ Conduct of Monitoring Yes
63.8(c)(1)-(8)................ CMS Operation/ Yes
Maintenance.
63.8(d)....................... Quality Control...... Yes
[[Page 14219]]
63.8(e)....................... Performance Yes
Evaluation for CMS.
63.8(f)(1)-(f)(5)............. Alternative Yes
Monitoring Method.
63.8(f)(6).................... Alternative to RATA Yes
Test.
63.8(g)....................... Data Reduction....... Yes
63.9(a)....................... Notification Yes............................... Additional
Requirements. notification
requirements in Sec.
363.1351 (c).
63.9(b)(1)-(5)................ Initial Notifications Yes
63.9(c)....................... Request for Yes
Compliance Extension.
63.9(d)....................... New Source Yes
Notification for
Special Compliance
Requirements.
63.9(e)....................... Notification of Yes
Performance Test.
63.9(f)....................... Notification of VE/ Yes Notification not
Opacity Test. required for VE/
opacity test under
Sec. 63.1349.
63.9(g)....................... Additional CMS Yes
Notifications.
63.9(h)(1)-(h)(3)............. Notification of Yes
Compliance Status.
63.9(h)(4).................... ..................... No................................ [Reserved].
63.9(h)(5)-(h)(6)............. Notification of Yes
Compliance Status.
63.9(i)....................... Adjustment of Yes
Deadlines.
63.9(j)....................... Change in Previous Yes
Information.
63.10(a)...................... Recordkeeping/ Yes
Reporting.
63.10(b)...................... General Requirements. Yes
63.10(c)(1)................... Additional CMS Yes
Recordkeeping.
63.10(c)(2)-(c)(4)............ ..................... No................................ [Reserved].
63.10(c)(5)-(c)(8)............ Additional CMS Yes
Recordkeeping.
63.10(c)(9)................... ..................... No................................ [Reserved].
63.10(c)(10)-(15)............. Additional CMS Yes
Recordkeeping.
63.10(d)(1)................... General Reporting Yes
Requirements.
63.10(d)(2)................... Performance Test Yes
Results.
63.10(d)(3)................... Opacity or VE Yes
Observations.
63.10(d)(4)................... Progress Reports..... Yes
63.10(d)(5)................... Startup, Shutdown, Yes
Malfunction Reports.
63.10(e)(1)-(e)(2)............ Additional CMS Yes
Reports.
63.10(e)(3)................... Excess Emissions and Yes............................... Exceedences are
CMS Performance defined in Sec.
Reports. 63.1349.
63.10(f)...................... Waiver for Yes
Recordkeeping/
Reporting.
63.11(a)-(b).................. Control Device No................................ Flares not
Requirements. applicable.
63.12(a)-(c).................. State Authority and Yes
Delegations.
63.13(a)-(c).................. State/Regional Yes
Addresses.
63.14(a)-(b).................. Incorporation by Yes
Reference.
63.15(a)-(b).................. Availability of Yes
Information.
----------------------------------------------------------------------------------------------------------------
3. Appendix A of part 63 is amended by adding, in numerical order,
Methods 320, 321, and 322 to read as follows:
Appendix A to Part 63-Test Methods
* * * * *
METHOD 320
Measurement of Vapor Phase Organic and Inorganic Emissions by
Extractive Fourier Transform Infrared (FTIR) Spectroscopy
1.0 Introduction.
Persons unfamiliar with basic elements of FTIR spectroscopy
should not attempt to use this method. This method describes
sampling and analytical procedures for extractive emission
measurements using Fourier transform infrared (FTIR) spectroscopy.
Detailed analytical procedures for interpreting infrared spectra are
described in the ``Protocol for the Use of Extractive Fourier
Transform Infrared (FTIR) Spectrometry in Analyses of Gaseous
Emissions from Stationary Sources,'' hereafter referred to as the
``Protocol.'' Definitions not given in this method are given in
appendix A of the Protocol. References to specific sections in the
Protocol are made throughout this Method. For additional information
refer to references 1 and 2, and other EPA reports, which describe
the use of FTIR spectrometry in specific field measurement
applications and validation tests. The sampling procedure described
here is extractive. Flue gas is extracted through a heated gas
transport and handling system. For some sources, sample conditioning
systems may be applicable. Some examples are given in this method.
(Note: sample conditioning systems may be used providing the method
validation requirements in Sections 9.2 and 13.0 of this method are
met.)
1.1 Scope and Applicability.
1.1.1 Analytes. Analytes include hazardous air pollutants
(HAPs) for which EPA reference spectra have been developed. Other
compounds can also be measured with this method if reference spectra
are prepared according to section 4.6 of the protocol.
1.1.2 Applicability. This method applies to the analysis of
vapor phase organic or inorganic compounds which absorb energy in
the mid-infrared spectral region, about 400 to 4000 cm-1
(25 to 2.5 m). This method is used to determine compound-
specific concentrations in a multi-component vapor phase sample,
which is contained in a closed-path gas cell. Spectra of samples are
collected using double beam infrared absorption spectroscopy. A
computer program is used to analyze spectra and report compound
concentrations.
1.2 Method Range and Sensitivity. Analytical range and
sensitivity depend on the frequency-dependent analyte absorptivity,
instrument configuration, data collection parameters, and gas stream
composition. Instrument factors include: (a) spectral resolution,
(b) interferometer signal averaging time, (c) detector sensitivity
and response, and (d) absorption path length.
1.2.1 For any optical configuration the analytical range is
between the absorbance values of about .01 (infrared transmittance
relative to the background = 0.98) and 1.0 (T = 0.1). (For
absorbance > 1.0 the relation between absorbance and concentration
may not be linear.)
1.2.2 The concentrations associated with this absorbance range
depend primarily on the cell path length and the sample temperature.
An analyte absorbance greater than 1.0, can be lowered by decreasing
the
[[Page 14220]]
optical path length. Analyte absorbance increases with a longer path
length. Analyte detection also depends on the presence of other
species exhibiting absorbance in the same analytical region.
Additionally, the estimated lower absorbance (A) limit (A = 0.01)
depends on the root mean square deviation (RMSD) noise in the
analytical region.
1.2.3 The concentration range of this method is determined by
the choice of optical configuration.
1.2.3.1 The absorbance for a given concentration can be
decreased by decreasing the path length or by diluting the sample.
There is no practical upper limit to the measurement range.
1.2.3.2 The analyte absorbance for a given concentration may be
increased by increasing the cell path length or (to some extent)
using a higher resolution. Both modifications also cause a
corresponding increased absorbance for all compounds in the sample,
and a decrease in the signal throughput. For this reason the
practical lower detection range (quantitation limit) usually depends
on sample characteristics such as moisture content of the gas, the
presence of other interferants, and losses in the sampling system.
1.3 Sensitivity. The limit of sensitivity for an optical
configuration and integration time is determined using appendix D of
the Protocol: Minimum Analyte Uncertainty, (MAU). The MAU depends on
the RMSD noise in an analytical region, and on the absorptivity of
the analyte in the same region.
1.4 Data Quality. Data quality shall be determined by executing
Protocol pre-test procedures in appendices B to H of the protocol
and post-test procedures in appendices I and J of the protocol.
1.4.1 Measurement objectives shall be established by the choice
of detection limit (DLi) and analytical uncertainty
(AUi) for each analyte.
1.4.2 An instrumental configuration shall be selected. An
estimate of gas composition shall be made based on previous test
data, data from a similar source or information gathered in a pre-
test site survey. Spectral interferants shall be identified using
the selected DLi and AUi and band areas from
reference spectra and interferant spectra. The baseline noise of the
system shall be measured in each analytical region to determine the
MAU of the instrument configuration for each analyte and interferant
(MIUi).
1.4.3 Data quality for the application shall be determined, in
part, by measuring the RMS (root mean square) noise level in each
analytical spectral region (appendix C of the Protocol). The RMS
noise is defined as the RMSD of the absorbance values in an
analytical region from the mean absorbance value in the region.
1.4.4 The MAU is the minimum analyte concentration for which
the AUi can be maintained; if the measured analyte
concentration is less than MAUi, then data quality are
unacceptable.
2.0 Summary of Method.
2.1 Principle. References 4 through 7 provide background
material on infrared spectroscopy and quantitative analysis. A
summary is given in this section.
2.1.1 Infrared absorption spectroscopy is performed by
directing an infrared beam through a sample to a detector. The
frequency-dependent infrared absorbance of the sample is measured by
comparing this detector signal (single beam spectrum) to a signal
obtained without a sample in the beam path (background).
2.1.2 Most molecules absorb infrared radiation and the
absorbance occurs in a characteristic and reproducible pattern. The
infrared spectrum measures fundamental molecular properties and a
compound can be identified from its infrared spectrum alone.
2.1.3 Within constraints, there is a linear relationship
between infrared absorption and compound concentration. If this
frequency dependent relationship (absorptivity) is known (measured),
it can be used to determine compound concentration in a sample
mixture.
2.1.4 Absorptivity is measured by preparing, in the laboratory,
standard samples of compounds at known concentrations and measuring
the FTIR ``reference spectra'' of these standard samples. These
``reference spectra'' are then used in sample analysis: (1)
compounds are detected by matching sample absorbance bands with
bands in reference spectra, and (2) concentrations are measured by
comparing sample band intensities with reference band intensities.
2.1.5 This method is self-validating provided that the results
meet the performance requirement of the QA spike in sections 9.0 and
8.6.2 of this method, and results from a previous method validation
study support the use of this method in the application.
2.2 Sampling and Analysis. In extractive sampling a probe
assembly and pump are used to extract gas from the exhaust of the
affected source and transport the sample to the FTIR gas cell.
Typically, the sampling apparatus is similar to that used for
single-component continuous emission monitor (CEM) measurements.
2.2.1 The digitized infrared spectrum of the sample in the FTIR
gas cell is measured and stored on a computer. Absorbance band
intensities in the spectrum are related to sample concentrations by
what is commonly referred to as Beer's Law.
Ai = aibci (Eq. 320-1)
Where:
Ai = absorbance at a given frequency of the ith sample
component.
ai = absorption coefficient (absorptivity) of the ith
sample component.
b = path length of the cell.
ci = concentration of the ith sample component.
2.2.2 Analyte spiking is used for quality assurance (QA). In
this procedure (section 8.6.2 of this method) an analyte is spiked
into the gas stream at the back end of the sample probe. Analyte
concentrations in the spiked samples are compared to analyte
concentrations in unspiked samples. Since the concentration of the
spike is known, this procedure can be used to determine if the
sampling system is removing the spiked analyte(s) from the sample
stream.
2.3 Reference Spectra Availability. Reference spectra of over
100 HAPs are available in the EPA FTIR spectral library on the EMTIC
(Emission Measurement Technical Information Center) computer
bulletin board service and at internet address http://
info.arnold.af.mil/epa/welcome.htm. Reference spectra for HAPs, or
other analytes, may also be prepared according to section 4.6 of the
Protocol.
2.4 Operator Requirements. The FTIR analyst shall be trained in
setting up the instrumentation, verifying the instrument is
functioning properly, and performing routine maintenance. The
analyst must evaluate the initial sample spectra to determine if the
sample matrix is consistent with pre-test assumptions and if the
instrument configuration is suitable. The analyst must be able to
modify the instrument configuration, if necessary.
2.4.1 The spectral analysis shall be supervised by someone
familiar with EPA FTIR Protocol procedures.
2.4.2 A technician trained in CEM test methods is qualified to
install and operate the sampling system. This includes installing
the probe and heated line assembly, operating the analyte spike
system, and performing moisture and flow measurements.
3.0 Definitions.
See appendix A of the Protocol for definitions relating to
infrared spectroscopy. Additional definitions are given below.
3.1 Analyte. A compound that this method is used to measure.
The term ``target analyte'' is also used. This method is multi-
component and a number of analytes can be targeted for a test.
3.2 Reference Spectrum. Infrared spectrum of an analyte
prepared under controlled, documented, and reproducible laboratory
conditions according to procedures in section 4.6 of the Protocol. A
library of reference spectra is used to measure analytes in gas
samples.
3.3 Standard Spectrum. A spectrum that has been prepared from a
reference spectrum through a (documented) mathematical operation. A
common example is de-resolving of reference spectra to lower-
resolution standard spectra (Protocol, appendix K). Standard
spectra, prepared by approved, and documented, procedures can be
used as reference spectra for analysis.
3.4 Concentration. In this method concentration is expressed as
a molar concentration, in ppm-meters, or in (ppm-meters)/K, where K
is the absolute temperature (Kelvin). The latter units allow the
direct comparison of concentrations from systems using different
optical configurations or sampling temperatures.
3.5 Interferant. A compound in the sample matrix whose infrared
spectrum overlaps with part of an analyte spectrum. The most
accurate analyte measurements are achieved when reference spectra of
interferants are used in the quantitative analysis with the analyte
reference spectra.
The presence of an interferant can increase the analytical
uncertainty in the measured analyte concentration.
3.6 Gas Cell. A gas containment cell that can be evacuated. It
is equipped with the
[[Page 14221]]
optical components to pass the infrared beam through the sample to
the detector. Important cell features include: path length (or range
if variable), temperature range, materials of construction, and
total gas volume.
3.7 Sampling System. Equipment used to extract the sample from
the test location and transport the sample gas to the FTIR analyzer.
This includes sample conditioning systems.
3.8 Sample Analysis. The process of interpreting the infrared
spectra to obtain sample analyte concentrations. This process is
usually automated using a software routine employing a classical
least squares (cls), partial least squares (pls), or K- or P- matrix
method.
3.9 One hundred percent line. A double beam transmittance
spectrum obtained by combining two background single beam spectra.
Ideally, this line is equal to 100 percent transmittance (or zero
absorbance) at every frequency in the spectrum. Practically, a zero
absorbance line is used to measure the baseline noise in the
spectrum.
3.10 Background Deviation. A deviation from 100 percent
transmittance in any region of the 100 percent line. Deviations
greater than 5 percent in an analytical region are
unacceptable (absorbance of 0.021 to -0.022). Such deviations
indicate a change in the instrument throughput relative to the
background single beam.
3.11 Batch Sampling. A procedure where spectra of discreet,
static samples are collected. The gas cell is filled with sample and
the cell is isolated. The spectrum is collected. Finally, the cell
is evacuated to prepare for the next sample.
3.12 Continuous Sampling. A procedure where spectra are
collected while sample gas is flowing through the cell at a measured
rate.
3.13 Sampling resolution. The spectral resolution used to
collect sample spectra.
3.14 Truncation. Limiting the number of interferogram data
points by deleting points farthest from the center burst (zero path
difference, ZPD).
3.15 Zero filling. The addition of points to the interferogram.
The position of each added point is interpolated from neighboring
real data points. Zero filling adds no information to the
interferogram, but affects line shapes in the absorbance spectrum
(and possibly analytical results).
3.16 Reference CTS. Calibration Transfer Standard spectra that
were collected with reference spectra.
3.17 CTS Standard. CTS spectrum produced by applying a de-
resolution procedure to a reference CTS.
3.18 Test CTS. CTS spectra collected at the sampling resolution
using the same optical configuration as for sample spectra. Test
spectra help verify the resolution, temperature and path length of
the FTIR system.
3.19 RMSD. Root Mean Square Difference, defined in EPA FTIR
Protocol, appendix A.
3.20 Sensitivity. The noise-limited compound-dependent
detection limit for the FTIR system configuration. This is estimated
by the MAU. It depends on the RMSD in an analytical region of a zero
absorbance line.
3.21 Quantitation Limit. The lower limit of detection for the
FTIR system configuration in the sample spectra. This is estimated
by mathematically subtracting scaled reference spectra of analytes
and interferences from sample spectra, then measuring the RMSD in an
analytical region of the subtracted spectrum. Since the noise in
subtracted sample spectra may be much greater than in a zero
absorbance spectrum, the quantitation limit is generally much higher
than the sensitivity. Removing spectral interferences from the
sample or improving the spectral subtraction can lower the
quantitation limit toward (but not below) the sensitivity.
3.22 Independent Sample. A unique volume of sample gas; there
is no mixing of gas between two consecutive independent samples. In
continuous sampling two independent samples are separated by at
least 5 cell volumes. The interval between independent measurements
depends on the cell volume and the sample flow rate (through the
cell).
3.23 Measurement. A single spectrum of flue gas contained in
the FTIR cell.
3.24 Run. A run consists of a series of measurements. At a
minimum a run includes 8 independent measurements spaced over 1
hour.
3.25 Validation. Validation of FTIR measurements is described
in sections 13.0 through 13.4 of this method. Validation is used to
verify the test procedures for measuring specific analytes at a
source. Validation provides proof that the method works under
certain test conditions.
3.26 Validation Run. A validation run consists of at least 24
measurements of independent samples. Half of the samples are spiked
and half are not spiked. The length of the run is determined by the
interval between independent samples.
3.27 Screening. Screening is used when there is little or no
available information about a source. The purpose of screening is to
determine what analytes are emitted and to obtain information about
important sample characteristics such as moisture, temperature, and
interferences. Screening results are semi-quantitative (estimated
concentrations) or qualitative (identification only). Various
optical and sampling configurations may be used. Sample conditioning
systems may be evaluated for their effectiveness in removing
interferences. It is unnecessary to perform a complete run under any
set of sampling conditions. Spiking is not necessary, but spiking
can be a useful screening tool for evaluating the sampling system,
especially if a reactive or soluble analyte is used for the spike.
3.28 Emissions Test. An FTIR emissions test is performed
according specific sampling and analytical procedures. These
procedures, for the target analytes and the source, are based on
previous screening and validation results. Emission results are
quantitative. A QA spike (sections 8.6.2 and 9.2 of this method) is
performed under each set of sampling conditions using a
representative analyte. Flow, gas temperature and diluent data are
recorded concurrently with the FTIR measurements to provide mass
emission rates for detected compounds.
3.29 Surrogate. A surrogate is a compound that is used in a QA
spike procedure (section 8.6.2 of this method) to represent other
compounds. The chemical and physical properties of a surrogate shall
be similar to the compounds it is chosen to represent. Under given
sampling conditions, usually a single sampling factor is of primary
concern for measuring the target analytes: for example, the
surrogate spike results can be representative for analytes that are
more reactive, more soluble, have a lower absorptivity, or have a
lower vapor pressure than the surrogate itself.
4.0 Interferences.
Interferences are divided into two classifications: analytical
and sampling.
4.1 Analytical Interferences. An analytical interference is a
spectral feature that complicates (in extreme cases may prevent) the
analysis of an analyte. Analytical interferences are classified as
background or spectral interference.
4.1.1 Background Interference. This results from a change in
throughput relative to the single beam background. It is corrected
by collecting a new background and proceeding with the test. In
severe instances the cause must be identified and corrected.
Potential causes include: (1) deposits on reflective surfaces or
transmitting windows, (2) changes in detector sensitivity, (3) a
change in the infrared source output, or (4) failure in the
instrument electronics. In routine sampling throughput may degrade
over several hours. Periodically a new background must be collected,
but no other corrective action will be required.
4.1.2 Spectral Interference. This results from the presence of
interfering compound(s) (interferant) in the sample. Interferant
spectral features overlap analyte spectral features. Any compound
with an infrared spectrum, including analytes, can potentially be an
interferant. The Protocol measures absorbance band overlap in each
analytical region to determine if potential interferants shall be
classified as known interferants (FTIR Protocol, section 4.9 and
appendix B). Water vapor and CO2 are common spectral
interferants. Both of these compounds have strong infrared spectra
and are present in many sample matrices at high concentrations
relative to analytes. The extent of interference depends on the (1)
interferant concentration, (2) analyte concentration, and (3) the
degree of band overlap. Choosing an alternate analytical region can
minimize or avoid the spectral interference. For example,
CO2 interferes with the analysis of the 670
cm-1 benzene band. However, benzene can also be measured
near 3000 cm-1 (with less sensitivity).
4.2 Sampling System Interferences. These prevent analytes from
reaching the instrument. The analyte spike procedure is designed to
measure sampling system interference, if any.
4.2.1 Temperature. A temperature that is too low causes
condensation of analytes or water vapor. The materials of the
sampling system and the FTIR gas cell usually set the upper limit of
temperature.
4.2.2 Reactive Species. Anything that reacts with analytes.
Some analytes, like formaldehyde, polymerize at lower temperatures.
[[Page 14222]]
4.2.3 Materials. Poor choice of material for probe, or sampling
line may remove some analytes. For example, HF reacts with glass
components.
4.2.4 Moisture. In addition to being a spectral interferant,
condensed moisture removes soluble compounds.
5.0 Safety.
The hazards of performing this method are those associated with
any stack sampling method and the same precautions shall be
followed. Many HAPs are suspected carcinogens or present other
serious health risks. Exposure to these compounds should be avoided
in all circumstances. For instructions on the safe handling of any
particular compound, refer to its material safety data sheet. When
using analyte standards, always ensure that gases are properly
vented and that the gas handling system is leak free. (Always
perform a leak check with the system under maximum vacuum and,
again, with the system at greater than ambient pressure.) Refer to
section 8.2 of this method for leak check procedures. This method
does not address all of the potential safety risks associated with
its use. Anyone performing this method must follow safety and health
practices consistent with applicable legal requirements and with
prudent practice for each application.
6.0 Equipment and Supplies.
Note: Mention of trade names or specific products does not
constitute endorsement by the Environmental Protection Agency.
The equipment and supplies are based on the schematic of a
sampling system shown in Figure 1. Either the batch or continuous
sampling procedures may be used with this sampling system.
Alternative sampling configurations may also be used, provided that
the data quality objectives are met as determined in the post-
analysis evaluation. Other equipment or supplies may be necessary,
depending on the design of the sampling system or the specific
target analytes.
6.1 Sampling Probe. Glass, stainless steel, or other
appropriate material of sufficient length and physical integrity to
sustain heating, prevent adsorption of analytes, and to transport
analytes to the infrared gas cell. Special materials or
configurations may be required in some applications. For instance,
high stack sample temperatures may require special steel or cooling
the probe. For very high moisture sources it may be desirable to use
a dilution probe.
6.2 Particulate Filters. A glass wool plug (optional) inserted
at the probe tip (for large particulate removal) and a filter
(required) rated for 99 percent removal efficiency at 1-micron
(e.g., BalstonTM) connected at the outlet of the heated
probe.
6.3 Sampling Line/Heating System. Heated (sufficient to prevent
condensation) stainless steel, polytetrafluoroethane, or other
material inert to the analytes.
6.4 Gas Distribution Manifold. A heated manifold allowing the
operator to control flows of gas standards and samples directly to
the FTIR system or through sample conditioning systems. Usually
includes heated flow meter, heated valve for selecting and sending
sample to the analyzer, and a by-pass vent. This is typically
constructed of stainless steel tubing and fittings, and high-
temperature valves.
6.5 Stainless Steel Tubing. Type 316, appropriate diameter
(e.g., \3/8\ in.) and length for heated connections. Higher grade
stainless may be desirable in some applications.
6.6 Calibration/Analyte Spike Assembly. A three way valve
assembly (or equivalent) to introduce analyte or surrogate spikes
into the sampling system at the outlet of the probe upstream of the
out-of-stack particulate filter and the FTIR analytical system.
6.7 Mass Flow Meter (MFM). These are used for measuring analyte
spike flow. The MFM shall be calibrated in the range of 0 to 5 L/min
and be accurate to 2 percent (or better) of the flow
meter span.
6.8 Gas Regulators. Appropriate for individual gas standards.
6.9 Polytetrafluoroethane Tubing. Diameter (e.g., \3/8\ in.)
and length suitable to connect cylinder regulators to gas standard
manifold.
6.10 Sample Pump. A leak-free pump (e.g., KNFTM),
with by-pass valve, capable of producing a sample flow rate of at
least 10 L/min through 100 ft of sample line. If the pump is
positioned upstream of the distribution manifold and FTIR system,
use a heated pump that is constructed from materials non-reactive to
the analytes. If the pump is located downstream of the FTIR system,
the gas cell sample pressure will be lower than ambient pressure and
it must be recorded at regular intervals.
6.11 Gas Sample Manifold. Secondary manifold to control sample
flow at the inlet to the FTIR manifold. This is optional, but
includes a by-pass vent and heated rotameter.
6.12 Rotameter. A 0 to 20 L/min rotameter. This meter need not
be calibrated.
6.13 FTIR Analytical System. Spectrometer and detector, capable
of measuring the analytes to the chosen detection limit. The system
shall include a personal computer with compatible software allowing
automated collection of spectra.
6.14 FTIR Cell Pump. Required for the batch sampling technique,
capable of evacuating the FTIR cell volume within 2 minutes. The
pumping speed shall allow the operator to obtain 8 sample spectra in
1 hour.
6.15 Absolute Pressure Gauge. Capable of measuring pressure
from 0 to 1000 mmHg to within 2.5 mmHg (e.g.,
BaratronTM).
6.16 Temperature Gauge. Capable of measuring the cell
temperature to within 2 deg.C.
6.17 Sample Conditioning. One option is a condenser system,
which is used for moisture removal. This can be helpful in the
measurement of some analytes. Other sample conditioning procedures
may be devised for the removal of moisture or other interfering
species.
6.17.1 The analyte spike procedure of section 9.2 of this
method, the QA spike procedure of section 8.6.2 of this method, and
the validation procedure of section 13 of this method demonstrate
whether the sample conditioning affects analyte concentrations.
Alternatively, measurements can be made with two parallel FTIR
systems; one measuring conditioned sample, the other measuring
unconditioned sample.
6.17.2 Another option is sample dilution. The dilution factor
measurement must be documented and accounted for in the reported
concentrations. An alternative to dilution is to lower the
sensitivity of the FTIR system by decreasing the cell path length,
or to use a short-path cell in conjunction with a long path cell to
measure more than one concentration range.
7.0 Reagents and Standards.
7.1 Analyte(s) and Tracer Gas. Obtain a certified gas cylinder
mixture containing all of the analyte(s) at concentrations within
2 percent of the emission source levels (expressed in
ppm-meter/K). If practical, the analyte standard cylinder shall also
contain the tracer gas at a concentration which gives a measurable
absorbance at a dilution factor of at least 10:1. Two ppm
SF6 is sufficient for a path length of 22 meters at 250
deg.F.
7.2 Calibration Transfer Standard(s). Select the calibration
transfer standards (CTS) according to section 4.5 of the FTIR
Protocol. Obtain a National Institute of Standards and Technology
(NIST) traceable gravimetric standard of the CTS (2
percent).
7.3 Reference Spectra. Obtain reference spectra for each
analyte, interferant, surrogate, CTS, and tracer. If EPA reference
spectra are not available, use reference spectra prepared according
to procedures in section 4.6 of the EPA FTIR Protocol.
8.0 Sampling and Analysis Procedure.
Three types of testing can be performed: (1) screening, (2)
emissions test, and (3) validation. Each is defined in section 3 of
this method. Determine the purpose(s) of the FTIR test. Test
requirements include: (a) AUI, DLI, overall
fractional uncertainty, OFUI, maximum expected
concentration (CMAXI), and tAN for each, (b)
potential interferants, (c) sampling system factors, e.g., minimum
absolute cell pressure, (PMIN), FTIR cell volume
(VSS), estimated sample absorption pathlength,
LS', estimated sample pressure, PS',
TS', signal integration time (tSS), minimum
instrumental linewidth, MIL, fractional error, and (d) analytical
regions, e.g., m = 1 to M, lower wavenumber position,
FLM, center wavenumber position, FCM, and
upper wavenumber position, FUM, plus interferants, upper
wavenumber position of the CTS absorption band, FFUM,
lower wavenumber position of the CTS absorption band,
FFLM, wavenumber range FNU to FNL. If necessary, sample
and acquire an initial spectrum. From analysis of this preliminary
spectrum determine a suitable operational path length. Set up the
sampling train as shown in Figure 1 or use an appropriate
alternative configuration. Sections 8.1 through 8.11 of this method
provide guidance on pre-test calculations in the EPA protocol,
sampling and analytical procedures, and post-test protocol
calculations.
8.1 Pretest Preparations and Evaluations. Using the procedure
in section 4.0 of the FTIR Protocol, determine the optimum sampling
system configuration for measuring the target analytes. Use
available information to make reasonable assumptions about moisture
content and other interferences.
[[Page 14223]]
8.1.1 Analytes. Select the required detection limit
(DLi) and the maximum permissible analytical uncertainty
(AUi) for each analyte (labeled from 1 to i). Estimate,
if possible, the maximum expected concentration for each analyte,
CMAXi. The expected measurement range is fixed by
DLi and CMAXi for each analyte (i).
8.1.2 Potential Interferants. List the potential interferants.
This usually includes water vapor and CO2, but may also
include some analytes and other compounds.
8.1.3 Optical Configuration. Choose an optical configuration
that can measure all of the analytes within the absorbance range of
.01 to 1.0 (this may require more than one path length). Use
Protocol sections 4.3 to 4.8 for guidance in choosing a
configuration and measuring CTS.
8.1.4 Fractional Reproducibility Uncertainty (FRUi).
The FRU is determined for each analyte by comparing CTS spectra
taken before and after the reference spectra were measured. The EPA
para-xylene reference spectra were collected on 10/31/91 and 11/01/
91 with corresponding CTS spectra ``cts1031a,'' and ``cts1101b.''
The CTS spectra are used to estimate the reproducibility (FRU) in
the system that was used to collect the references. The FRU must be
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spectra in EPA reference library: S3 (cts1101b--
cts1031a), and S4 [(cts1101b + cts1031a)/2]. The RMSD
(SRMS) is calculated in the subtracted baseline, S3, in
the corresponding CTS region from 850 to 1065 cm-1. The
area (BAV) is calculated in the same region of the averaged CTS
spectrum, S4.
8.1.5 Known Interferants. Use appendix B of the EPA FTIR
Protocol.
8.1.6 Calculate the Minimum Analyte Uncertainty, MAU (section
1.3 of this method discusses MAU and protocol appendix D gives the
MAU procedure). The MAU for each analyte, i, and each analytical
region, m, depends on the RMS noise.
8.1.7 Analytical Program. See FTIR Protocol, section 4.10.
Prepare computer program based on the chosen analytical technique.
Use as input reference spectra of all target analytes and expected
interferants. Reference spectra of additional compounds shall also
be included in the program if their presence (even if transient) in
the samples is considered possible. The program output shall be in
ppm (or ppb) and shall be corrected for differences between the
reference path length, LR, temperature, TR,
and pressure, PR, and the conditions used for collecting
the sample spectra. If sampling is performed at ambient pressure,
then any pressure correction is usually small relative to
corrections for path length and temperature, and may be neglected.
8.2 Leak-check.
8.2.1 Sampling System. A typical FTIR extractive sampling train
is shown in Figure 1. Leak check from the probe tip to pump outlet
as follows: Connect a 0- to 250-mL/min rate meter (rotameter or
bubble meter) to the outlet of the pump. Close off the inlet to the
probe, and record the leak rate. The leak rate shall be
200 mL/min.
8.2.2 Analytical System Leak check. Leak check the FTIR cell
under vacuum and under pressure (greater than ambient). Leak check
connecting tubing and inlet manifold under pressure.
8.2.2.1 For the evacuated sample technique, close the valve to
the FTIR cell, and evacuate the absorption cell to the minimum
absolute pressure Pmin. Close the valve to the pump, and
determine the change in pressure Pv after 2
minutes.
8.2.2.2 For both the evacuated sample and purging techniques,
pressurize the system to about 100 mmHg above atmospheric pressure.
Isolate the pump and determine the change in pressure
Pp after 2 minutes.
8.2.2.3 Measure the barometric pressure, Pb in mmHg.
8.2.2.4 Determine the percent leak volume %VL for
the signal integration time tSS and for
Pmax, i.e., the larger of Pv
or Pp, as follows:
[GRAPHIC] [TIFF OMITTED] TP24MR98.004
Where 50=100% divided by the leak-check time of 2 minutes.
8.2.2.5 Leak volumes in excess of 4 percent of the FTIR system
volume VSS are unacceptable.
8.3 Detector Linearity. Once an optical configuration is
chosen, use one of the procedures of sections 8.3.1 through 8.3.3 to
verify that the detector response is linear. If the detector
response is not linear, decrease the aperture, or attenuate the
infrared beam. After a change in the instrument configuration
perform a linearity check until it is demonstrated that the detector
response is linear.
8.3.1 Vary the power incident on the detector by modifying the
aperture setting. Measure the background and CTS at three instrument
aperture settings: (1) at the aperture setting to be used in the
testing, (2) at one half this aperture and (3) at twice the proposed
testing aperture. Compare the three CTS spectra. CTS band areas
shall agree to within the uncertainty of the cylinder standard and
the RMSD noise in the system. If test aperture is the maximum
aperture, collect CTS spectrum at maximum aperture, then close the
aperture to reduce the IR throughput by half. Collect a second
background and CTS at the smaller aperture setting and compare the
spectra again.
8.3.2 Use neutral density filters to attenuate the infrared
beam. Set up the FTIR system as it will be used in the test
measurements. Collect a CTS spectrum. Use a neutral density filter
to attenuate the infrared beam (either immediately after the source
or the interferometer) to approximately \1/2\ its original
intensity. Collect a second CTS spectrum. Use another filter to
attenuate the infrared beam to approximately \1/4\ its original
intensity. Collect a third background and CTS spectrum. Compare the
CTS spectra. CTS band areas shall agree to within the uncertainty of
the cylinder standard and the RMSD noise in the system.
8.3.3 Observe the single beam instrument response in a
frequency region where the detector response is known to be zero.
Verify that the detector response is ``flat'' and equal to zero in
these regions.
8.4 Data Storage Requirements. All field test spectra shall be
stored on a computer disk and a second backup copy must stored on a
separate disk. The stored information includes sample
interferograms, processed absorbance spectra, background
interferograms, CTS sample interferograms and CTS absorbance
spectra. Additionally, documentation of all sample conditions,
instrument settings, and test records must be recorded on hard copy
or on computer medium. Table 1 to this method gives a sample
presentation of documentation.
8.5 Background Spectrum. Evacuate the gas cell to 5
mmHg, and fill with dry nitrogen gas to ambient pressure (or purge
the cell with 10 volumes of dry nitrogen). Verify that no
significant amounts of absorbing species (for example water vapor
and CO2) are present. Collect a background spectrum,
using a signal averaging period equal to or greater than the
averaging period for the sample spectra. Assign a unique file name
to the background spectrum. Store two copies of the background
interferogram and processed single-beam spectrum on separate
computer disks (one copy is the back-up).
8.5.1 Interference Spectra. If possible, collect spectra of
known and suspected major interferences using the same optical
system that will be used in the field measurements. This can be done
on-site or earlier. A number of gases, e.g. CO2,
SO2, CO, NH3, are readily available from
cylinder gas suppliers.
8.5.2 Water vapor spectra can be prepared by the following
procedure. Fill a sample tube with distilled water. Evacuate above
the sample and remove dissolved gasses by alternately freezing and
thawing the water while evacuating. Allow water vapor into the FTIR
cell, then dilute to atmospheric pressure with nitrogen or dry air.
If quantitative water spectra are required, follow the reference
spectrum procedure for neat samples (protocol, section 4.6). Often,
interference spectra need not be quantitative, but for best results
the absorbance must be comparable to the interference absorbance in
the sample spectra.
8.6 Pre-Test Calibrations
8.6.1 Calibration Transfer Standard. Evacuate the gas cell to
5 mmHg absolute pressure, and fill the FTIR cell to
atmospheric pressure with the CTS gas. Alternatively, purge the cell
with 10 cell volumes of CTS gas. (If purge is used, verify that the
CTS concentration in the cell is stable by collecting two spectra 2
minutes apart as the CTS gas continues to flow. If the absorbance in
the second spectrum is no greater than in the first, within the
uncertainty of the gas standard, then this can be used as the CTS
spectrum.) Record the spectrum.
8.6.2 QA Spike. This procedure assumes that the method has been
validated for at least some of the target analytes at the source.
For emissions testing perform a QA spike. Use a certified standard,
if possible, of an analyte, which has been validated at the source.
One analyte standard can serve as a QA surrogate for other analytes
which are less reactive or less soluble than the
[[Page 14224]]
standard. Perform the spike procedure of section 9.2 of this method.
Record spectra of at least three independent (section 3.22 of this
method) spiked samples. Calculate the spiked component of the
analyte concentration. If the average spiked concentration is within
0.7 to 1.3 times the expected concentration, then proceed with the
testing. If applicable, apply the correction factor from the Method
301 of this appendix validation test (not the result from the QA
spike).
8.7 Sampling. If analyte concentrations vary rapidly with time,
CEM sampling is preferable using the smallest cell volume, fastest
sampling rate and fastest spectra collection rate possible. CEM
sampling requires the least operator intervention even without an
automated sampling system. For continuous monitoring at one location
over long periods, CEM sampling is preferred. Batch sampling and
continuous static sampling are used for screening and performing
test runs of finite duration. Either technique is preferred for
sampling several locations in a matter of days. Batch sampling gives
reasonably good time resolution and ensures that each spectrum
measures a discreet (and unique) sample volume. Continuous static
(and CEM) sampling provide a very stable background over long
periods. Like batch sampling, continuous static sampling also
ensures that each spectrum measures a unique sample volume. It is
essential that the leak check procedure under vacuum (section 8.2 of
this method) is passed if the batch sampling procedure is used. It
is essential that the leak check procedure under positive pressure
is passed if the continuous static or CEM sampling procedures are
used. The sampling techniques are described in sections 8.7.1
through 8.7.2 of this method.
8.7.1 Batch Sampling. Evacuate the absorbance cell to
5 mmHg absolute pressure. Fill the cell with exhaust gas
to ambient pressure, isolate the cell, and record the spectrum.
Before taking the next sample, evacuate the cell until no spectral
evidence of sample absorption remains. Repeat this procedure to
collect eight spectra of separate samples in 1 hour.
8.7.2 Continuous Static Sampling. Purge the FTIR cell with 10
cell volumes of sample gas. Isolate the cell, collect the spectrum
of the static sample and record the pressure. Before measuring the
next sample, purge the cell with 10 more cell volumes of sample gas.
8.8 Sampling QA and Reporting.
8.8.1 Sample integration times shall be sufficient to achieve
the required signal-to-noise ratio. Obtain an absorbance spectrum by
filling the cell with N2. Measure the RMSD in each
analytical region in this absorbance spectrum. Verify that the
number of scans used is sufficient to achieve the target MAU.
8.8.2 Assign a unique file name to each spectrum.
8.8.3 Store two copies of sample interferograms and processed
spectra on separate computer disks.
8.8.4 For each sample spectrum, document the sampling
conditions, the sampling time (while the cell was being filled), the
time the spectrum was recorded, the instrumental conditions (path
length, temperature, pressure, resolution, signal integration time),
and the spectral file name. Keep a hard copy of these data sheets.
8.9 Signal Transmittance. While sampling, monitor the signal
transmittance. If signal transmittance (relative to the background)
changes by 5 percent or more (absorbance = -.02 to .02) in any
analytical spectral region, obtain a new background spectrum.
8.10 Post-test CTS. After the sampling run, record another CTS
spectrum.
8.11 Post-test QA.
8.11.1 Inspect the sample spectra immediately after the run to
verify that the gas matrix composition was close to the expected
(assumed) gas matrix.
8.11.2 Verify that the sampling and instrumental parameters
were appropriate for the conditions encountered. For example, if the
moisture is much greater than anticipated, it may be necessary to
use a shorter path length or dilute the sample.
8.11.3 Compare the pre- and post-test CTS spectra. The peak
absorbance in pre- and post-test CTS must be # 5 percent
of the mean value. See appendix E of the FTIR Protocol.
9.0 Quality Control.
Use analyte spiking (sections 8.6.2, 9.2 and 13.0 of this
method) to verify that the sampling system can transport the
analytes from the probe to the FTIR system.
9.1 Spike Materials. Use a certified standard (accurate to
2 percent) of the target analyte, if one can be
obtained. If a certified standard cannot be obtained, follow the
procedures in section 4.6.2.2 of the FTIR Protocol.
9.2 Spiking Procedure. QA spiking (section 8.6.2 of this
method) is a calibration procedure used before testing. QA spiking
involves following the spike procedure of sections 9.2.1 through
9.2.3 of this method to obtain at least three spiked samples. The
analyte concentrations in the spiked samples shall be compared to
the expected spike concentration to verify that the sampling system
is working properly. Usually, when QA spiking is used, the method
has already been validated at a similar source for the analyte in
question. The QA spike demonstrates that the validated sampling
conditions are being duplicated. If the QA spike fails then the
sampling system shall be repaired before testing proceeds. The
method validation procedure (section 13.0 of this method) involves a
more extensive use of the analyte spike procedure of sections 9.2.1
through 9.2.3 of this method. Spectra of at least 12 independent
spiked and 12 independent unspiked samples are recorded. The
concentration results are analyzed statistically to determine if
there is a systematic bias in the method for measuring a particular
analyte. If there is a systematic bias, within the limits allowed by
Method 301 of this appendix, then a correction factor shall be
applied to the analytical results. If the systematic bias is greater
than the allowed limits, this method is not valid and cannot be
used.
9.2.1 Introduce the spike/tracer gas at a constant flow rate of
10 percent of the total sample flow. (Note: Use the
rotameter at the end of the sampling train to estimate the required
spike/tracer gas flow rate.) Use a flow device, e.g., mass flow
meter ( 2 percent), to monitor the spike flow rate.
Record the spike flow rate every 10 minutes.
9.2.2 Determine the response time (RT) of the system by
continuously collecting spectra of the spiked effluent until the
spectrum of the spiked component is constant for 5 minutes. The RT
is the interval from the first measurement until the spike becomes
constant. Wait for twice the duration of the RT, then collect
spectra of two independent spiked gas samples. Duplicate analyses of
the spiked concentration shall be within 5 percent of the mean of
the two measurements.
9.2.3 Calculate the dilution ratio using the tracer gas as
follows:
[GRAPHIC] [TIFF OMITTED] TP24MR98.005
Where:
[GRAPHIC] [TIFF OMITTED] TP24MR98.006
DF = Dilution factor of the spike gas; this value shall be
10.
SF6(dir) = SF6 (or tracer gas) concentration
measured directly in undiluted spike gas.
SF6(spk) = Diluted SF6 (or tracer gas)
concentration measured in a spiked sample.
Spikedir = Concentration of the analyte in the spike
standard measured by filling the FTIR cell directly.
CS = Expected concentration of the spiked samples.
10.0 Calibration and Standardization.
10.1 Signal-to-Noise Ratio (S/N). The RMSD in the noise must be
less than one tenth of the minimum analyte peak absorbance in each
analytical region. For example if the minimum peak absorbance is
0.01 at the required DL, then RMSD measured over the entire
analytical region must be 0.001.
10.2 Absorbance Path length. Verify the absorbance path length
by comparing reference CTS spectra to test CTS spectra. See appendix
E of the FTIR Protocol.
10.3 Instrument Resolution. Measure the line width of
appropriate test CTS band(s) to verify instrument resolution.
Alternatively, compare CTS spectra to a reference CTS spectrum, if
available, measured at the nominal resolution.
10.4 Apodization Function. In transforming the sample
interferograms to absorbance spectra use the same apodization
function that was used in transforming the reference spectra.
10.5 FTIR Cell Volume. Evacuate the cell to 5 mmHg.
Measure the initial absolute temperature (Ti) and
absolute pressure (Pi). Connect a wet test meter (or a
calibrated dry gas meter), and slowly draw room air into the cell.
Measure the meter volume (Vm), meter absolute temperature
(Tm), and meter absolute pressure (Pm); and
the cell final absolute temperature (Tf) and absolute
[[Page 14225]]
pressure (Pf). Calculate the FTIR cell volume
VSS, including that of the connecting tubing, as follows:
[GRAPHIC] [TIFF OMITTED] TP24MR98.007
11.0 Data Analysis and Calculations.
Analyte concentrations shall be measured using reference spectra
from the EPA FTIR spectral library. When EPA library spectra are not
available, the procedures in section 4.6 of the Protocol shall be
followed to prepare reference spectra of all the target analytes.
11.1 Spectral De-resolution. Reference spectra can be converted to
lower resolution standard spectra (section 3.3 of this method) by
truncating the original reference sample and background
interferograms. Appendix K of the FTIR Protocol gives specific
deresolution procedures. Deresolved spectra shall be transformed
using the same apodization function and level of zero filling as the
sample spectra. Additionally, pre-test FTIR protocol calculations
(e.g., FRU, MAU, FCU) shall be performed using the de-resolved
standard spectra.
11.2 Data Analysis. Various analytical programs are available
for relating sample absorbance to a concentration standard.
Calculated concentrations shall be verified by analyzing residual
baselines after mathematically subtracting scaled reference spectra
from the sample spectra. A full description of the data analysis and
calculations is contained in the FTIR Protocol (sections 4.0, 5.0,
6.0 and appendices). Correct the calculated concentrations in the
sample spectra for differences in absorption path length and
temperature between the reference and sample spectra using equation
6,
[GRAPHIC] [TIFF OMITTED] TP24MR98.008
Where:
Ccorr = Concentration, corrected for path length.
Ccalc = Concentration, initial calculation (output of
the analytical program designed for the compound).
Lr = Reference spectra path length.
Ls = Sample spectra path length.
Ts = Absolute temperature of the sample gas, K.
Tr = Absolute gas temperature of reference spectra, K.
12.0 Method Performance.
12.1 Spectral Quality. Refer to the FTIR Protocol appendices
for analytical requirements, evaluation of data quality, and
analysis of uncertainty.
12.2 Sampling QA/QC. The analyte spike procedure of section 9
of this method, the QA spike of section 8.6.2 of this method, and
the validation procedure of section 13 of this method are used to
evaluate the performance of the sampling system and to quantify
sampling system effects, if any, on the measured concentrations.
This method is self-validating provided that the results meet the
performance requirement of the QA spike in sections 9.0 and 8.6.2 of
this method and results from a previous method validation study
support the use of this method in the application. Several factors
can contribute to uncertainty in the measurement of spiked samples.
Factors which can be controlled to provide better accuracy in the
spiking procedure are listed in sections 12.2.1 through 12.2.4 of
this method.
12.2.1 Flow meter. An accurate mass flow meter is accurate to
1 percent of its span. If a flow of 1 L/min is
monitored with such a MFM, which is calibrated in the range of 0-5
L/min, the flow measurement has an uncertainty of 5 percent. This
may be improved by re-calibrating the meter at the specific flow
rate to be used.
12.2.2 Calibration gas. Usually the calibration standard is
certified to within 2 percent. With reactive analytes,
such as HCl, the certified accuracy in a commercially available
standard may be no better than 5 percent.
12.2.3 Temperature. Temperature measurements of the cell shall
be quite accurate. If practical, it is preferable to measure sample
temperature directly, by inserting a thermocouple into the cell
chamber instead of monitoring the cell outer wall temperature.
12.2.4 Pressure. Accuracy depends on the accuracy of the
barometer, but fluctuations in pressure throughout a day may be as
much as 2.5 percent due to weather variations.
13.0 Method Validation Procedure.
This validation procedure, which is based on EPA Method 301 (40
CFR part 63, appendix A), may be used to validate this method for
the analytes in a gas matrix. Validation at one source may also
apply to another type of source, if it can be shown that the exhaust
gas characteristics are similar at both sources.
13.1 Section 5.3 of Method 301 (40 CFR part 63, appendix A),
the Analyte Spike procedure, is used with these modifications. The
statistical analysis of the results follows section 6.3 of EPA
Method 301. Section 3 of this method defines terms that are not
defined in Method 301.
13.1.1 The analyte spike is performed dynamically. This means
the spike flow is continuous and constant as spiked samples are
measured.
13.1.2 The spike gas is introduced at the back of the sample
probe.
13.1.3 Spiked effluent is carried through all sampling
components downstream of the probe.
13.1.4 A single FTIR system (or more) may be used to collect
and analyze spectra (not quadruplicate integrated sampling trains).
13.1.5 All of the validation measurements are performed
sequentially in a single ``run'' (section 3.26 of this method).
13.1.6 The measurements analyzed statistically are each
independent (section 3.22 of this method).
13.1.7 A validation data set can consist of more than 12 spiked
and 12 unspiked measurements.
13.2 Batch Sampling. The procedure in sections 13.2.1 through
13.2.2 may be used for stable processes. If process emissions are
highly variable, the procedure in section 13.2.3 shall be used.
13.2.1 With a single FTIR instrument and sampling system, begin
by collecting spectra of two unspiked samples. Introduce the spike
flow into the sampling system and allow 10 cell volumes to purge the
sampling system and FTIR cell. Collect spectra of two spiked
samples. Turn off the spike and allow 10 cell volumes of unspiked
sample to purge the FTIR cell. Repeat this procedure until the 24
(or more) samples are collected.
13.2.2 In batch sampling, collect spectra of 24 distinct
samples. (Each distinct sample consists of filling the cell to
ambient pressure after the cell has been evacuated.)
13.2.3 Alternatively, a separate probe assembly, line, and
sample pump can be used for spiked sample. Verify and document that
sampling conditions are the same in both the spiked and the unspiked
sampling systems. This can be done by wrapping both sample lines in
the same heated bundle. Keep the same flow rate in both sample
lines. Measure samples in sequence in pairs. After two spiked
samples are measured, evacuate the FTIR cell, and turn the manifold
valve so that spiked sample flows to the FTIR cell. Allow the
connecting line from the manifold to the FTIR cell to purge
thoroughly (the time depends on the line length and flow rate).
Collect a pair of spiked samples. Repeat the procedure until at
least 24 measurements are completed.
13.3 Simultaneous Measurements With Two FTIR Systems. If
unspiked effluent concentrations of the target analyte(s) vary
significantly with time, it may be desirable to perform synchronized
measurements of spiked and unspiked sample. Use two FTIR systems,
each with its own cell and sampling system to perform simultaneous
spiked and unspiked measurements. The optical configurations shall
be similar, if possible. The sampling configurations shall be the
same. One sampling system and FTIR analyzer shall be used to measure
spiked effluent. The other sampling system and FTIR analyzer shall
be used to measure unspiked flue gas. Both systems shall use the
same sampling procedure (i.e., batch or continuous).
13.3.1 If batch sampling is used, synchronize the cell
evacuation, cell filling, and collection of spectra. Fill both cells
at the same rate (in cell volumes per unit time).
13.3.2 If continuous sampling is used, adjust the sample flow
through each gas cell so that the same number of cell volumes pass
through each cell in a given time (i.e. TC1 =
TC2).
13.4 Statistical Treatment. The statistical procedure of EPA
Method 301 of this appendix, section 6.3 is used to evaluate the
bias and precision. For FTIR testing a validation ``run'' is defined
as spectra of 24 independent samples, 12 of which are spiked with
the analyte(s) and 12 of which are not spiked.
13.4.1 Bias. Determine the bias (defined by EPA Method 301 of
this appendix, section 6.3.2) using equation 7:
B = Sm - Mm - CS (Eq. 320-7)
Where:
B = Bias at spike level.
[[Page 14226]]
Sm = Mean concentration of the analyte spiked samples.
Mm = Mean concentration of the unspiked samples.
CS = Expected concentration of the spiked samples.
13.4.2 Correction Factor. Use section 6.3.2.2 of Method 301 of
this appendix to evaluate the statistical significance of the bias.
If it is determined that the bias is significant, then use section
6.3.3 of Method 301 to calculate a correction factor (CF).
Analytical results of the test method are multiplied by the
correction factor, if 0.7 CF 1.3. If it is
determined that the bias is significant and CF > 30
percent, then the test method is considered to be ``not valid.''
13.4.3 If measurements do not pass validation, evaluate the
sampling system, instrument configuration, and analytical system to
determine if improper set-up or a malfunction was the cause. If so,
repair the system and repeat the validation.
14.0 Pollution Prevention.
The extracted sample gas is vented outside the enclosure
containing the FTIR system and gas manifold after the analysis. In
typical method applications the vented sample volume is a small
fraction of the source volumetric flow and its composition is
identical to that emitted from the source. When analyte spiking is
used, spiked pollutants are vented with the extracted sample gas.
Approximately 1.6 x 10-4 to 3.2 x 10-4 lbs
of a single HAP may be vented to the atmosphere in a typical
validation run of 3 hours. (This assumes a molar mass of 50 to 100
g, spike rate of 1.0 L/min, and a standard concentration of 100
ppm). Minimize emissions by keeping the spike flow off when not in
use.
15.0 Waste Management.
Small volumes of laboratory gas standards can be vented through
a laboratory hood. Neat samples must be packed and disposed
according to applicable regulations. Surplus materials may be
returned to supplier for disposal.
16.0 References.
1. ``Field Validation Test Using Fourier Transform Infrared
(FTIR) Spectrometry To Measure Formaldehyde, Phenol and Methanol at
a Wool Fiberglass Production Facility.'' Draft. U.S. Environmental
Protection Agency Report, EPA Contract No. 68D20163, Work Assignment
I-32, September 1994.
2. ``FTIR Method Validation at a Coal-Fired Boiler''. Prepared
for U.S. Environmental Protection Agency, Research Triangle Park,
NC. Publication No.: EPA-454/R95-004, NTIS No.: PB95-193199. July,
1993.
3. ``Method 301--Field Validation of Pollutant Measurement
Methods from Various Waste Media,'' 40 CFR part 63, appendix A.
4. ``Molecular Vibrations; The Theory of Infrared and Raman
Vibrational Spectra,'' E. Bright Wilson, J.C. Decius, and P.C.
Cross, Dover Publications, Inc., 1980. For a less intensive
treatment of molecular rotational-vibrational spectra see, for
example, ``Physical Chemistry,'' G.M. Barrow, chapters 12, 13, and
14, McGraw Hill, Inc., 1979.
5. ``Fourier Transform Infrared Spectrometry,'' Peter R.
Griffiths and James de Haseth, Chemical Analysis, 83, 16-25, (1986),
P.J. Elving, J.D. Winefordner and I.M. Kolthoff (ed.), John Wiley
and Sons.
6. ``Computer-Assisted Quantitative Infrared Spectroscopy,''
Gregory L. McClure (ed.), ASTM Special Publication 934 (ASTM), 1987.
7. ``Multivariate Least-Squares Methods Applied to the
Quantitative Spectral Analysis of Multicomponent Mixtures,'' Applied
Spectroscopy, 39(10), 73-84, 1985.
Table 1.--Example Presentation of Sampling Documentation
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Background file Sample
Sample time Spectrum file name name conditioning Process condition
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Sample time Spectrum file Interferogram Resolution Scans Apodization Gain CTS spectrum
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Addendum to Method 320--Protocol for the Use of Extractive Fourier
Transform Infrared (FTIR) Spectrometry for the Analyses of Gaseous
Emissions From Stationary Sources
1.0 Introduction
The purpose of this addendum is to set general guidelines for
the use of modern FTIR spectroscopic methods for the analysis of gas
samples extracted from the effluent of stationary emission sources.
This addendum outlines techniques for developing and evaluating such
methods and sets basic requirements for reporting and quality
assurance procedures.
1.1 Nomenclature
1.1.1 Attachment A to this addendum lists definitions of the
symbols and terms used in this Protocol, many of which have been
taken directly from American Society for Testing and Materials
(ASTM) publication E 131-90a, entitled ``Terminology Relating to
Molecular Spectroscopy.''
1.1.2 Except in the case of background spectra or where
otherwise noted, the term ``spectrum'' refers to a double-beam
spectrum in units of absorbance vs. wavenumber (cm-1).
1.1.3 The term ``Study'' in this addendum refers to a
publication that has been subjected to EPA- or peer-review.
2.0 Applicability and Analytical Principle
2.1 Applicability. This Protocol applies to the determination
of compound-specific concentrations in single- and multiple-
component gas phase samples using double-beam absorption
spectroscopy in the mid-infrared band. It does not specifically
address other FTIR applications, such as single-beam spectroscopy,
analysis of open-path (non-enclosed) samples, and continuous
measurement techniques. If multiple spectrometers, absorption cells,
or instrumental linewidths are used in such analyses, each distinct
operational configuration of the system must be evaluated separately
according to this Protocol.
2.2 Analytical Principle.
2.2.1 In the mid-infrared band, most molecules exhibit
characteristic gas phase absorption spectra that may be recorded by
FTIR systems. Such systems consist of a source of mid-infrared
radiation, an interferometer, an enclosed sample cell of known
absorption pathlength, an infrared detector, optical elements for
the transfer of infrared radiation between components, and gas flow
control and measurement components. Adjunct and integral computer
systems are used for controlling the instrument, processing the
signal, and for performing both Fourier transforms and quantitative
analyses of spectral data.
2.2.2 The absorption spectra of pure gases and of mixtures of
gases are described by a linear absorbance theory referred to as
Beer's Law. Using this law, modern FTIR systems use computerized
analytical programs to quantify compounds by comparing the
absorption spectra of known (reference) gas samples to the
absorption spectrum of the sample gas. Some standard mathematical
techniques used for comparisons are classical least squares, inverse
least squares, cross-correlation, factor analysis, and partial least
squares. Reference A describes several of these techniques, as well
as additional techniques, such as differentiation methods, linear
baseline corrections, and non-linear absorbance corrections.
3.0 General Principles of Protocol Requirements
The characteristics that distinguish FTIR systems from gas
analyzers used in instrumental gas analysis methods (e.g., Methods
6C and 7E of appendix A to part 60 of this chapter) are: (1)
Computers are necessary to obtain and analyze data; (2) chemical
concentrations can be quantified using previously recorded infrared
reference spectra; and (3) analytical assumptions and results,
including possible effects of interfering compounds, can be
evaluated after the quantitative analysis. The following general
principles and requirements of this Protocol are based on these
characteristics.
3.1 Verifiability and Reproducibility of Results. Store all
data and document data analysis techniques sufficient to allow an
independent agent to reproduce the analytical results from the raw
interferometric data.
3.2 Transfer of Reference Spectra. To determine whether
reference spectra recorded under one set of conditions (e.g.,
optical bench, instrumental linewidth, absorption pathlength,
detector performance, pressure, and temperature) can be used to
analyze sample spectra taken under a different set of conditions,
quantitatively compare ``calibration transfer standards'' (CTS) and
reference spectra as described in this Protocol. (Note: The CTS may,
but need not, include analytes of interest). To effect this, record
the absorption spectra of the CTS (a) immediately before and
immediately after recording reference spectra and (b) immediately
after recording sample spectra.
3.3 Evaluation of FTIR Analyses. The applicability, accuracy,
and precision of FTIR measurements are influenced by a number of
interrelated factors, which may be divided into two classes:
3.3.1 Sample-Independent Factors. Examples are system
configuration and performance (e.g., detector sensitivity and
infrared source output), quality and applicability of reference
absorption spectra, and type of mathematical analyses of the
spectra. These factors define the fundamental limitations of FTIR
measurements for a given system configuration. These limitations may
be estimated from evaluations of the system before samples are
available.
For example, the detection limit for the absorbing compound
under a given set of conditions may be estimated from the system
noise level and the strength of a particular absorption band.
Similarly, the accuracy of measurements may be estimated from the
analysis of the reference spectra.
3.3.2 Sample-Dependent Factors. Examples are spectral
interferants (e.g., water vapor and CO2) or the overlap
of spectral features of different compounds and contamination
deposits on reflective surfaces or transmitting windows. To maximize
the effectiveness of the mathematical techniques used in spectral
analysis, identification of interferants (a standard initial step)
and analysis of samples (includes effect of other analytical errors)
are necessary. Thus, the Protocol requires post-analysis calculation
of measurement concentration uncertainties for the detection of
these potential sources of measurement error.
4.0 Pre-Test Preparations and Evaluations
Before testing, demonstrate the suitability of FTIR spectrometry
for the desired application according to the procedures of this
section.
4.1 Identify Test Requirements. Identify and record the test
requirements described in sections 4.1.1 through 4.1.4 of this
addendum. These values set the desired or required goals of the
proposed analysis; the description of methods for determining
whether these goals are actually met during the analysis comprises
the majority of this Protocol.
4.1.1 Analytes (specific chemical species) of interest. Label
the analytes from i = 1 to I.
4.1.2 Analytical uncertainty limit (AUi). The
AUi is the maximum permissible fractional uncertainty of
analysis for the ith analyte concentration, expressed as
a fraction of the analyte concentration in the sample.
4.1.3 Required detection limit for each analyte
(DLi, ppm). The detection limit is the lowest
concentration of an analyte for which its overall fractional
uncertainty (OFUi) is required to be less than its
analytical uncertainty limit (AUi).
4.1.4 Maximum expected concentration of each analyte
(CMAXi, ppm).
4.2 Identify Potential Interferants. Considering the chemistry
of the process or results of previous studies, identify potential
interferants, i.e., the major effluent constituents and any
relatively minor effluent constituents that possess either strong
absorption characteristics or strong structural similarities to any
analyte of interest. Label them 1 through Nj, where the
subscript ``j'' pertains to potential interferants. Estimate the
concentrations of these compounds in the effluent (CPOTj,
ppm).
4.3 Select and Evaluate the Sampling System. Considering the
source, e.g., temperature and pressure profiles, moisture content,
analyte characteristics, and particulate concentration, select the
equipment for extracting gas samples. Recommended are a particulate
filter, heating system to maintain sample temperature above the dew
point for all sample constituents at all points within the sampling
system (including the filter), and sample conditioning system (e.g.,
coolers, water-permeable membranes that remove water or other
compounds from the sample, and dilution devices) to remove spectral
interferants or to protect the sampling and analytical components.
Determine the minimum absolute sample system pressure
(Pmin, mmHg) and the infrared absorption cell volume
(VSS, liter). Select the techniques and/or equipment for
the measurement of sample pressures and temperatures.
4.4 Select Spectroscopic System. Select a spectroscopic
configuration for the
[[Page 14230]]
application. Approximate the absorption pathlength (LS',
meter), sample pressure (PS', kPa), absolute sample
temperature TS', and signal integration period
(tSS, seconds) for the analysis. Specify the nominal
minimum instrumental linewidth (MIL) of the system. Verify that the
fractional error at the approximate values PS' and
TS' is less than one half the smallest value
AUi (see section 4.1.2 of this addendum).
4.5 Select Calibration Transfer Standards (CTS's). Select CTS's
that meet the criteria listed in sections 4.5.1, 4.5.2, and 4.5.3 of
this addendum. (Note: It may be necessary to choose preliminary
analytical regions (see section 4.7 of this addendum), identify the
minimum analyte linewidths, or estimate the system noise level (see
section 4.12 of this addendum) before selecting the CTS. More than
one compound may be needed to meet the criteria; if so, obtain
separate cylinders for each compound.)
4.5.1 The central wavenumber position of each analytical region
shall lie within 25 percent of the wavenumber position of at least
one CTS absorption band.
4.5.2 The absorption bands in section 4.5.1 of this addendum
shall exhibit peak absorbances greater than ten times the value
RMSEST (see section 4.12 of this addendum) but less than
1.5 absorbance units.
4.5.3 At least one absorption CTS band within the operating
range of the FTIR instrument shall have an instrument-independent
linewidth no greater than the narrowest analyte absorption band.
Perform and document measurements or cite Studies to determine
analyte and CTS compound linewidths.
4.5.4 For each analytical region, specify the upper and lower
wavenumber positions (FFUm and FFLm,
respectively) that bracket the CTS absorption band or bands for the
associated analytical region. Specify the wavenumber range, FNU to
FNL, containing the absorption band that meets the criterion of
section 4.5.3 of this addendum.
4.5.5 Associate, whenever possible, a single set of CTS gas
cylinders with a set of reference spectra.
Replacement CTS gas cylinders shall contain the same compounds
at concentrations within 5 percent of that of the original CTS
cylinders; the entire absorption spectra (not individual spectral
segments) of the replacement gas shall be scaled by a factor between
0.95 and 1.05 to match the original CTS spectra.
4.6 Prepare Reference Spectra. (Note: Reference spectra are
available in a permanent soft copy from the EPA spectral library on
the EMTIC (Emission Measurement Technical Information Center)
computer bulletin board; they may be used if applicable.)
4.6.1 Select the reference absorption pathlength
(LR) of the cell.
4.6.2 Obtain or prepare a set of chemical standards for each
analyte, potential and known spectral interferants, and CTS. Select
the concentrations of the chemical standards to correspond to the
top of the desired range.
4.6.2.1 Commercially-Prepared Chemical Standards. Chemical
standards for many compounds may be obtained from independent
sources, such as a specialty gas manufacturer, chemical company, or
commercial laboratory. These standards (accurate to within
2 percent) shall be prepared according to EPA
Traceability Protocol (see Reference D) or shall be traceable to
NIST standards. Obtain from the supplier an estimate of the
stability of the analyte concentration. Obtain and follow all of the
supplier's recommendations for recertifying the analyte
concentration.
4.6.2.2 Self-Prepared Chemical Standards. Chemical standards
may be prepared by diluting certified commercially prepared chemical
gases or pure analytes with ultra-pure carrier (UPC) grade nitrogen
according to the barometric and volumetric techniques generally
described in Reference A, section A4.6.
4.6.3 Record a set of the absorption spectra of the CTS {R1},
then a set of the reference spectra at two or more concentrations in
duplicate over the desired range (the top of the range must be less
than 10 times that of the bottom), followed by a second set of CTS
spectra {R2}. (If self-prepared standards are used, see section
4.6.5 of this addendum before disposing of any of the standards.)
The maximum accepted standard concentration-pathlength product
(ASCPP) for each compound shall be higher than the maximum estimated
concentration-pathlength products for both analytes and known
interferants in the effluent gas. For each analyte, the minimum
ASCPP shall be no greater than ten times the concentration-
pathlength product of that analyte at its required detection limit.
4.6.4 Permanently store the background and interferograms in
digitized form. Document details of the mathematical process for
generating the spectra from these interferograms. Record the sample
pressure (PR), sample temperature (TR),
reference absorption pathlength (LR), and interferogram
signal integration period (tSR). Signal integration
periods for the background interferograms shall be
tSR. Values of PR, LR,
and tSR shall not deviate by more than 1
percent from the time of recording {R1} to that of recording {R2}.
4.6.5 If self-prepared chemical standards are employed and
spectra of only two concentrations are recorded for one or more
compounds, verify the accuracy of the dilution technique by
analyzing the prepared standards for those compounds with a
secondary (non-FTIR) technique in accordance with sections 4.6.5.1
through 4.6.5.4 of this addendum.
4.6.5.1 Record the response of the secondary technique to each
of the four standards prepared.
4.6.5.2 Perform a linear regression of the response values
(dependant variable) versus the accepted standard concentration
(ASC) values (independent variable), with the regression constrained
to pass through the zero-response, zero ASC point.
4.6.5.3 Calculate the average fractional difference between the
actual response values and the regression-predicted values (those
calculated from the regression line using the four ASC values as the
independent variable).
4.6.5.4 If the average fractional difference value calculated
in section 4.6.5.3 of this addendum is larger for any compound than
the corresponding AUi, the dilution technique is not sufficiently
accurate and the reference spectra prepared are not valid for the
analysis.
4.7 Select Analytical Regions. Using the general considerations
in section 7 of Reference A and the spectral characteristics of the
analytes and interferants, select the analytical regions for the
application. Label them m = 1 to M. Specify the lower, center and
upper wavenumber positions of each analytical region
(FLm, FCm, and FUm, respectively).
Specify the analytes and interferants which exhibit absorption in
each region.
4.8 Determine Fractional Reproducibility Uncertainties. Using
attachement E of this addendum, calculate the fractional
reproducibility uncertainty for each analyte (FRUi) from
a comparison of {R1} and {R2}. If FRUi > AUi
for any analyte, the reference spectra generated in accordance with
section 4.6 of this addendum are not valid for the application.
4.9 Identify Known Interferants. Using attachment B of this
addendum, determine which potential interferants affect the analyte
concentration determinations. Relabel these potential interferant as
``known'' interferants, and designate these compounds from k = 1 to
K. Attachment B to this addendum also provides criteria for
determining whether the selected analytical regions are suitable.
4.10 Prepare Computerized Analytical Programs.
4.10.1 Choose or devise mathematical techniques (e.g, classical
least squares, inverse least squares, cross-correlation, and factor
analysis) based on equation 4 of Reference A that are appropriate
for analyzing spectral data by comparison with reference spectra.
4.10.2 Following the general recommendations of Reference A,
prepare a computer program or set of programs that analyzes all of
the analytes and known interferants, based on the selected
analytical regions (section 4.7 of this addendum) and the prepared
reference spectra (section 4.6 of this addendum). Specify the
baseline correction technique (e.g., determining the slope and
intercept of a linear baseline contribution in each analytical
region) for each analytical region, including all relevant
wavenumber positions.
4.10.3 Use programs that provide as output [at the reference
absorption pathlength (LR), reference gas temperature
(TR), and reference gas pressure (PR)] the
analyte concentrations, the known interferant concentrations, and
the baseline slope and intercept values. If the sample absorption
pathlength (LS), sample gas temperature (TS),
or sample gas pressure (PS) during the actual sample
analyses differ from LR, TR, and
PR, use a program or set of programs that applies
multiplicative corrections to the derived concentrations to account
for these variations, and that provides as output both the corrected
and uncorrected values. Include in the report of the analysis (see
section 7.0 of this addendum) the details of any transformations
applied to the original reference spectra (e.g., differentiation),
in such a fashion that all analytical results may
[[Page 14231]]
be verified by an independent agent from the reference spectra and
data spectra alone.
4.11 Determine the Fractional Calibration Uncertainty.
Calculate the fractional calibration uncertainty for each analyte
(FCUi) according to attachment F of this addendum, and
compare these values to the fractional uncertainty limits
(AUi; see section 4.1.2 of this addendum). If
FCUi > AUi, either the reference spectra or
analytical programs for that analyte are unsuitable.
4.12 Verify System Configuration Suitability. Using attachment
C of this addendum, measure or obtain estimates of the noise level
(RMSEST, absorbance) of the FTIR system. Alternatively,
construct the complete spectrometer system and determine the values
RMSSm using attachment G of this addendum. Estimate the
minimum measurement uncertainty for each analyte (MAUi,
ppm) and known interferant (MIUk, ppm) using attachment D
of this addendum. Verify that (a) MAUi <>i)
(DLi), FRUi <>i, and
FCUi <>i for each analyte and that (b) the
CTS chosen meets the requirements listed in sections 4.5.1 through
4.5.5 of this addendum.
5.0 Sampling and Analysis Procedure
5.1 Analysis System Assembly and Leak-Test. Assemble the
analysis system. Allow sufficient time for all system components to
reach the desired temperature. Then, determine the leak-rate
(LR) and leak volume (VL), where VL
= LR tSS. Leak volumes shall be 4
percent of VSS.
5.2 Verify Instrumental Performance. Measure the noise level of
the system in each analytical region using the procedure of
attachment G of this addendum. If any noise level is higher than
that estimated for the system in section 4.12 of this addendum,
repeat the calculations of attachment D of this addendum and verify
that the requirements of section 4.12 of this addendum are met; if
they are not, adjust or repair the instrument and repeat this
section.
5.3 Determine the Sample Absorption Pathlength. Record a
background spectrum. Then, fill the absorption cell with CTS at the
pressure PR and record a set of CTS spectra {R3}. Store
the background and unscaled CTS single beam interferograms and
spectra. Using attachment H of this addendum, calculate the sample
absorption pathlength (LS) for each analytical region.
The values LS shall not differ from the approximated
sample pathlength LS' (see section 4.4 of this addendum)
by more than 5 percent.
5.4 Record Sample Spectrum. Connect the sample line to the
source. Either evacuate the absorption cell to an absolute pressure
below 5 mmHg before extracting a sample from the effluent stream
into the absorption cell, or pump at least ten cell volumes of
sample through the cell before obtaining a sample. Record the sample
pressure PS. Generate the absorbance spectrum of the
sample. Store the background and sample single beam interferograms,
and document the process by which the absorbance spectra are
generated from these data. (If necessary, apply the spectral
transformations developed in section 5.6.2 of this addendum). The
resulting sample spectrum is referred to below as SS.
(Note: Multiple sample spectra may be recorded according to the
procedures of section 5.4 of this addendum before performing
sections 5.5 and 5.6 of this addendum.)
5.5 Quantify Analyte Concentrations. Calculate the unscaled
analyte concentrations RUAi and unscaled interferant
concentrations RUIK using the programs developed in
section 4 of this addendum. To correct for pathlength and pressure
variations between the reference and sample spectra, calculate the
scaling factor, RLPS using equation A.1,
RLPS = (LRPRTS)/
(LSPSTR) ((Eq. 320-A.1)
Calculate the final analyte and interferant concentrations
RSAi and RSIk using equations A.2 and A.3,
RSAi = RLPSRUAi (Eq. 320-A.2)
RSIk = RLPSRUIk (Eq. 320-A.3)
5.6 Determine Fractional Analysis Uncertainty. Fill the
absorption cell with CTS at the pressure PS. Record a set
of CTS spectra {R4}. Store the background and CTS single beam
interferograms. Using appendix H of this addendum, calculate the
fractional analysis uncertainty (FAU) for each analytical region. If
the FAU indicated for any analytical region is greater than the
required accuracy requirements determined in sections 4.1.1 through
4.1.4 of this addendum, then comparisons to previously recorded
reference spectra are invalid in that analytical region, and the
analyst shall perform one or both of the procedures of sections
5.6.1 through 5.6.2 of this addendum.
5.6.1 Perform instrumental checks and adjust the instrument to
restore its performance to acceptable levels. If adjustments are
made, repeat sections 5.3, 5.4 (except for the recording of a sample
spectrum), and 5.5 of this addendum to demonstrate that acceptable
uncertainties are obtained in all analytical regions.
5.6.2 Apply appropriate mathematical transformations (e.g.,
frequency shifting, zero-filling, apodization, smoothing) to the
spectra (or to the interferograms upon which the spectra are based)
generated during the performance of the procedures of section 5.3 of
this addendum. Document these transformations and their
reproducibility. Do not apply multiplicative scaling of the spectra,
or any set of transformations that is mathematically equivalent to
multiplicative scaling. Different transformations may be applied to
different analytical regions. Frequency shifts shall be less than
one-half the minimum instrumental linewidth, and must be applied to
all spectral data points in an analytical region. The mathematical
transformations may be retained for the analysis if they are also
applied to the appropriate analytical regions of all sample spectra
recorded, and if all original sample spectra are digitally stored.
Repeat sections 5.3, 5.4 (except the recording of a sample
spectrum), and 5.5 of this addendum to demonstrate that these
transformations lead to acceptable calculated concentration
uncertainties in all analytical regions.
6.0 Post-Analysis Evaluations
Estimate the overall accuracy of the analyses performed in
accordance with sections 5.1 through 5.6 of this addendum using the
procedures of sections 6.1 through 6.3 of this addendum.
6.1 Qualitatively Confirm the Assumed Matrix. Examine each
analytical region of the sample spectrum for spectral evidence of
unexpected or unidentified interferants. If found, identify the
interfering compounds (see Reference C for guidance) and add them to
the list of known interferants. Repeat the procedures of section 4
of this addendum to include the interferants in the uncertainty
calculations and analysis procedures. Verify that the MAU and FCU
values do not increase beyond acceptable levels for the application
requirements. Re-calculate the analyte concentrations (section 5.5
of this addendum) in the affected analytical regions.
6.2 Quantitatively Evaluate Fractional Model Uncertainty (FMU).
Perform the procedures of either section 6.2.1 or 6.2.2 of this
addendum:
6.2.1 Using appendix I of this addendum, determine the
fractional model error (FMU) for each analyte.
6.2.2 Provide statistically determined uncertainties FMU for
each analyte which are equivalent to two standard deviations at the
95 percent confidence level. Such determinations, if employed, must
be based on mathematical examinations of the pertinent sample
spectra (not the reference spectra alone). Include in the report of
the analysis (see section 7.0 of this addendum) a complete
description of the determination of the concentration uncertainties.
6.3 Estimate Overall Concentration Uncertainty (OCU). Using
appendix J of this addendum, determine the overall concentration
uncertainty (OCU) for each analyte. If the OCU is larger than the
required accuracy for any analyte, repeat sections 4 and 6 of this
addendum.
7.0 Reporting Requirements
[Documentation pertaining to virtually all the procedures of
sections 4, 5, and 6 will be required. Software copies of reference
spectra and sample spectra will be retained for some minimum time
following the actual testing.]
8.0 References
(A) Standard Practices for General Techniques of Infrared
Quantitative Analysis (American Society for Testing and Materials,
Designation E 168-88).
(B) The Coblentz Society Specifications for Evaluation of
Research Quality Analytical Infrared Reference Spectra (Class II);
Anal. Chemistry 47, 945A (1975); Appl. Spectroscopy 444, pp. 211-
215, 1990.
(C) Standard Practices for General Techniques for Qualitative
Infrared Analysis, American Society for Testing and Materials,
Designation E 1252-88.
(D) ``EPA Traceability Protocol for Assay and Certification of
Gaseous Calibration Standards,'' U.S. Environmental Protection
Agency Publication No. EPA/600/R-93/224, December 1993.
Attachment A to Addendum to Method 320--Definitions of Terms and
Symbols
A.1 Definitions of Terms. All terms used in this method that
are not defined below have the meaning given to them in the CAA and
in subpart A of this part.
[[Page 14232]]
Absorption band means a contiguous wavenumber region of a
spectrum (equivalently, a contiguous set of absorbance spectrum data
points) in which the absorbance passes through a maximum or a series
of maxima.
Absorption pathlength means the distance in a spectrophotometer,
measured in the direction of propagation of the beam of radiant
energy, between the surface of the specimen on which the radiant
energy is incident and the surface of the specimen from which it is
emergent.
Analytical region means a contiguous wavenumber region
(equivalently, a contiguous set of absorbance spectrum data points)
used in the quantitative analysis for one or more analytes. (Note:
The quantitative result for a single analyte may be based on data
from more than one analytical region.)
Apodization means modification of the ILS function by
multiplying the interferogram by a weighing function whose magnitude
varies with retardation.
Background spectrum means the single beam spectrum obtained with
all system components without sample present.
Baseline means any line drawn on an absorption spectrum to
establish a reference point that represents a function of the
radiant power incident on a sample at a given wavelength.
Beers's law means the direct proportionality of the absorbance
of a compound in a homogeneous sample to its concentration.
Calibration transfer standard (CTS) gas means a gas standard of
a compound used to achieve and/or demonstrate suitable quantitative
agreement between sample spectra and the reference spectra; see
section 4.5.1 of this addendum.
Compound means a substance possessing a distinct, unique
molecular structure.
Concentration (c) means the quantity of a compound contained in
a unit quantity of sample. The unit ``ppm'' (number, or mole, basis)
is recommended.
Concentration-pathlength product means the mathematical product
of concentration of the species and absorption pathlength. For
reference spectra, this is a known quantity; for sample spectra, it
is the quantity directly determined from Beer's law. The units
``centimeters-ppm'' or ``meters-ppm'' are recommended.
Derivative absorption spectrum means a plot of rate of change of
absorbance or of any function of absorbance with respect to
wavelength or any function of wavelength.
Double beam spectrum means a transmission or absorbance spectrum
derived by dividing the sample single beam spectrum by the
background spectrum.(Note: The term ``double-beam'' is used
elsewhere to denote a spectrum in which the sample and background
interferograms are collected simultaneously along physically
distinct absorption paths. Here, the term denotes a spectrum in
which the sample and background interferograms are collected at
different times along the same absorption path.)
Fast Fourier transform (FFT) means a method of speeding up the
computation of a discrete FT by factoring the data into sparse
matrices containing mostly zeros.
Flyback means interferometer motion during which no data are
recorded.
Fourier transform (FT) means the mathematical process for
converting an amplitude-time spectrum to an amplitude-frequency
spectrum, or vice versa.
Fourier transform infrared (FTIR) spectrometer means an
analytical system that employs a source of mid-infrared radiation,
an interferometer, an enclosed sample cell of known absorption
pathlength, an infrared detector, optical elements that transfer
infrared radiation between components, and a computer system. The
time-domain detector response (interferogram) is processed by a
Fourier transform to yield a representation of the detector response
vs. infrared frequency. (Note: When FTIR spectrometers are
interfaced with other instruments, a slash should be used to denote
the interface; e.g., GC/FTIR; HPCL/FTIR, and the use of FTIR should
be explicit; i.e., FTIR not IR.)
Frequency, v means the number of cycles per unit time.
Infrared means the portion of the electromagnetic spectrum
containing wavelengths from approximately 0.78 to 800 microns.
Interferogram, I() means record of the modulated
component of the interference signal measured as a function of
retardation by the detector.
Interferometer means device that divides a beam of radiant
energy into two or more paths, generates an optical path difference
between the beams, and recombines them in order to produce
repetitive interference maxima and minima as the optical retardation
is varied.
Linewidth means the full width at half maximum of an absorption
band in units of wavenumbers (cm-1).
Mid-infrared means the region of the electromagnetic spectrum
from approximately 400 to 5000 cm-1.
Reference spectra means absorption spectra of gases with known
chemical compositions, recorded at a known absorption pathlength,
which are used in the quantitative analysis of gas samples.
Retardation, means optical path difference between two
beams in an interferometer; also known as ``optical path
difference'' or ``optical retardation.''
Scan means digital representation of the detector output
obtained during one complete motion of the interferometer's moving
assembly or assemblies.
Scaling means application of a multiplicative factor to the
absorbance values in a spectrum.
Single beam spectrum means Fourier-transformed interferogram,
representing the detector response vs. wavenumber. (Note: The term
``single-beam'' is used elsewhere to denote any spectrum in which
the sample and background interferograms are recorded on the same
physical absorption path; such usage differentiates such spectra
from those generated using interferograms recorded along two
physically distinct absorption paths (see ``double-beam spectrum''
above). Here, the term applies (for example) to the two spectra used
directly in the calculation of transmission and absorbance spectra
of a sample.)
Standard reference material means a reference material, the
composition or properties of which are certified by a recognized
standardizing agency or group. (Note: The equivalent ISO term is
``certified reference material.'')
Transmittance, T means the ratio of radiant power transmitted by
the sample to the radiant power incident on the sample. Estimated in
FTIR spectroscopy by forming the ratio of the single-beam sample and
background spectra.
Wavenumber, v means the number of waves per unit length. (Note:
The usual unit of wavenumber is the reciprocal centimeter,
cm-1. The wavenumber is the reciprocal of the wavelength,
, when is expressed in centimeters.) Zero-filling
means the addition of zero-valued points to the end of a measured
interferogram. (Note: Performing the FT of a zero-filled
interferogram results in correctly interpolated points in the
computed spectrum.)
A.2 Definitions of Mathematical Symbols. The symbols used in
equations in this subpart are defined as follows:
(1) A, absorbance = the logarithm to the base 10 of the
reciprocal of the transmittance (T).
[GRAPHIC] [TIFF OMITTED] TP24MR98.009
(2) AAIim = band area of the ith analyte
in the mth analytical region, at the concentration
(CLi) corresponding to the product of its required
detection limit (DLi) and analytical uncertainty limit
(AUi) .
(3) AAVim = average absorbance of the ith
analyte in the mth analytical region, at the
concentration (CLi) corresponding to the product of its
required detection limit (DLi) and analytical uncertainty
limit (AUi) .
(4) ASC, accepted standard concentration = the concentration
value assigned to a chemical standard.
(5) ASCPP, accepted standard concentration-pathlength product =
for a chemical standard, the product of the ASC and the sample
absorption pathlength. The units ``centimeters-ppm'' or ``meters-
ppm'' are recommended.
(6) AUi, analytical uncertainty limit = the maximum
permissible fractional uncertainty of analysis for the
ith analyte concentration, expressed as a fraction of the
analyte concentration determined in the analysis.
(7) AVTm = average estimated total absorbance in the
mth analytical region.
(8) CKWNk = estimated concentration of the
kth known interferant.
(9) CMAXi = estimated maximum concentration of the
ith analyte.
(10) CPOTj = estimated concentration of the
jth potential interferant.
(11) DLi, required detection limit = for the
ith analyte, the lowest concentration of the analyte for
which its overall fractional uncertainty (OFUi) is
required to be less than the analytical uncertainty limit
(AUi).
(12) FCm = center wavenumber position of the
mth analytical region.
(13) FAUi, fractional analytical uncertainty =
calculated uncertainty in the measured concentration of the
ith analyte because of errors in the mathematical
comparison of reference and sample spectra.
[[Page 14233]]
(14) FCUi, fractional calibration uncertainty =
calculated uncertainty in the measured concentration of the
ith analyte because of errors in Beer's law modeling of
the reference spectra concentrations.
(15) FFLm = lower wavenumber position of the CTS
absorption band associated with the mth analytical
region.
(16) FFUm = upper wavenumber position of the CTS
absorption band associated with the mth analytical
region.
(17) FLm = lower wavenumber position of the
mth analytical region.
(18) FMUi, fractional model uncertainty = calculated
uncertainty in the measured concentration of the ith
analyte because of errors in the absorption model employed.
(19) FNL = lower wavenumber position of the CTS
spectrum containing an absorption band at least as narrow as the
analyte absorption bands.
(20) FNU = upper wavenumber position of the CTS
spectrum containing an absorption band at least as narrow as the
analyte absorption bands.
(21) FRUi, fractional reproducibility uncertainty =
calculated uncertainty in the measured concentration of the
ith analyte because of errors in the reproducibility of
spectra from the FTIR system.
(22) FUm = upper wavenumber position of the
mth analytical region.
(23) IAIjm = band area of the jth
potential interferant in the mth analytical region, at
its expected concentration (CPOTj).
(24) IAVim = average absorbance of the ith
analyte in the mth analytical region, at its expected
concentration (CPOTj).
(25) ISCi or k, indicated standard concentration =
the concentration from the computerized analytical program for a
single-compound reference spectrum for the ith analyte or
kth known interferant.
(26) kPa = kilo-Pascal (see Pascal).
(27) LS' = estimated sample absorption pathlength.
(28) LR = reference absorption pathlength.
(29) LS = actual sample absorption pathlength.
(30) MAUi = mean of the MAUim over the
appropriate analytical regions.
(31) MAUim, minimum analyte uncertainty = the
calculated minimum concentration for which the analytical
uncertainty limit (AUi) in the measurement of the
ith analyte, based on spectral data in the mth
analytical region, can be maintained.
(32) MIUj = mean of the MIUjm over the
appropriate analytical regions.
(33) MIUjm, minimum interferant uncertainty = the
calculated minimum concentration for which the analytical
uncertainty limit CPOTj/20 in the measurement of the
jth interferant, based on spectral data in the
mth analytical region, can be maintained.
(34) MIL, minimum instrumental linewidth = the minimum linewidth
from the FTIR system, in wavenumbers. (Note: The MIL of a system may
be determined by observing an absorption band known (through higher
resolution examinations) to be narrower than indicated by the
system. The MIL is fundamentally limited by the retardation of the
interferometer, but is also affected by other operational parameters
(e.g., the choice of apodization).)
(35) Ni = number of analytes.
(36) Nj = number of potential interferants.
(37) Nk = number of known interferants.
(38) Nscan = the number of scans averaged to obtain
an interferogram.
(39) OFUi = the overall fractional uncertainty in an
analyte concentration determined in the analysis (OFUi =
MAX {FRU, FCUi, FAUi, FMUi }).
(40) Pascal (Pa) = metric unit of static pressure, equal to one
Newton per square meter; one atmosphere is equal to 101,325 Pa; 1/
760 atmosphere (one Torr, or one millimeter Hg) is equal to 133.322
Pa.
(41) Pmin = minimum pressure of the sampling system
during the sampling procedure.
(42) PS' = estimated sample pressure.
(43) PR = reference pressure.
(44) PS = actual sample pressure.
(45) RMSsm = measured noise level of the FTIR system
in the mth analytical region.
(46) RMSD, root mean square difference = a measure of accuracy
determined by the following equation:
[GRAPHIC] [TIFF OMITTED] TP24MR98.010
Where:
n = the number of observations for which the accuracy is determined.
ei = the difference between a measured value of a
property and its mean value over the n observations.
Note: The RMSD value ``between a set of n contiguous absorbance
values (Ai) and the mean of the values'' (AM)
is defined as
[GRAPHIC] [TIFF OMITTED] TP24MR98.011
(47) RSAi = the (calculated) final concentration of
the ith analyte.
(48) RSIk = the (calculated) final concentration of
the kth known interferant.
(49) tscan, scan time = time used to acquire a single
scan, not including flyback.
(50) tS, signal integration period = the period of
time over which an interferogram is averaged by addition and scaling
of individual scans. In terms of the number of scans
Nscan and scan time tscan, tS =
Nscantscan.
(51) tSR = signal integration period used in
recording reference spectra.
(52) tSS = signal integration period used in
recording sample spectra.
(53) TR = absolute temperature of gases used in
recording reference spectra.
(54) TS = absolute temperature of sample gas as
sample spectra are recorded.
(55) TP, Throughput = manufacturer's estimate of the fraction of
the total infrared power transmitted by the absorption cell and
transfer optics from the interferometer to the detector.
(56) VSS = volume of the infrared absorption cell,
including parts of attached tubing.
(57) Wik = weight used to average over analytical
regions k for quantities related to the analyte i; see attachment D
of this addendum.
Attachment B to Addendum to Method 320--Identifying Spectral
Interferants
B.1 General
B.1.1 Assume a fixed absorption pathlength equal to the value
LS'.
B.1.2 Use band area calculations to compare the relative
absorption strengths of the analytes and potential interferants. In
the mth analytical region (FLm to
FUm), use either rectangular or trapezoidal
approximations to determine the band areas described below (see
Reference A, sections A.3.1 through A.3.3). Document any baseline
corrections applied to the spectra.
B.1.3 Use the average total absorbance of the analytes and
potential interferants in each analytical region to determine
whether the analytical region is suitable for analyte concentration
determinations. (Note: The average absorbance in an analytical
region is the band area divided by the width of the analytical
region in wavenumbers. The average total absorbance in an analytical
region is the sum of the average absorbances of all analytes and
potential interferants.)
B.2 Calculations
B.2.1 Prepare spectral representations of each analyte at the
concentration CLi = (DLi)(AUi),
where DLi is the required detection limit and
AUi is the maximum permissible analytical uncertainty.
For the mth analytical region, calculate the band area
(AAIim) and average absorbance (AAVim) from
these scaled analyte spectra.
B.2.2 Prepare spectral representations of each potential
interferant at its expected concentration (CPOTj). For
the mth analytical region, calculate the band area
(IAIjm) and average absorbance (IAVjm) from
these scaled potential interferant spectra.
B.2.3 Repeat the calculation for each analytical region, and
record the band area results in matrix form as indicated in Figure
B.1.
B.2.4 If the band area of any potential interferant in an
analytical region is greater than the one-half the band area of any
analyte (i.e., IAIjm >0.5 AAIim for any pair
ij and any m), classify the potential interferant as a known
interferant. Label the known interferants k = 1 to K. Record the
results in matrix form as indicated in Figure B.2.
B.2.5 Calculate the average total absorbance (AVTm)
for each analytical region and record the values in the last row of
the matrix described in Figure B.2. Any analytical region where
AVTm >2.0 is unsuitable.
Figure B.1.--Presentation of Potential Interferant Calculations
------------------------------------------------------------------------
Analytical regions
-------------------------------------
1 M
------------------------------------------------------------------------
Analyte Labels
1................................. AAI11 AAI1M
I................................. AAII1 AAIIM
Potential Interferant Labels
1................................. IAI11 IAI1M
[[Page 14234]]
J................................. IAIJ1 IAIJM
------------------------------------------------------------------------
Figure B.2.--Presentation of Known Interferant Calculations
------------------------------------------------------------------------
Analytical regions
-------------------------------------
1 M
------------------------------------------------------------------------
Analyte Labels
1................................. AAI11 AAI1M
I................................. AAII1 AAIIM
Known Interferant Labels
1................................. IAI11 IAI1M
K................................. IAIK1 IAIKM
-------------------------------------
Total Average Absorbance...... AVT1 AVTM
------------------------------------------------------------------------
Attachment C to Addendum to Method 320--Estimating Noise Levels
C.1 General
C.1.1 The root-mean-square (RMS) noise level is the standard
measure of noise in this addendum. The RMS noise level of a
contiguous segment of a spectrum is defined as the RMS difference
(RMSD) between the absorbance values which form the segment and the
mean value of that segment (see attachment A of this addendum).
C.1.2 The RMS noise value in double-beam absorbance spectra is
assumed to be inversely proportional to: (a) the square root of the
signal integration period of the sample single beam spectra from
which it is formed, and (b) the total infrared power transmitted
through the interferometer and absorption cell.
C.1.3 Practically, the assumption of C.1.2 allows the RMS noise
level of a complete system to be estimated from the quantities
described in sections C.1.3.1 through C.1.3.4:
C.1.3.1 RMSMAN, the noise level of the system (in
absorbance units), without the absorption cell and transfer optics,
under those conditions necessary to yield the specified minimum
instrumental linewidth, e.g., Jacquinot stop size.
C.1.3.2 tMAN, the manufacturer's signal integration
time used to determine RMSMAN.
C.1.3.3 tSS, the signal integration time for the
analyses.
C.1.3.4 TP, the manufacturer's estimate of the fraction of the
total infrared power transmitted by the absorption cell and transfer
optics from the interferometer to the detector.
C.2 Calculations
C.2.1 Obtain the values of RMSMAN, tMAN,
and TP from the manufacturers of the equipment, or determine the
noise level by direct measurements with the completely constructed
system proposed in section 4 of this addendum.
C.2.2 Calculate the noise value of the system
(RMSEST) using equation C.1.
[GRAPHIC] [TIFF OMITTED] TP24MR98.012
Attachment D to Addendum to Method 320--Estimating Minimum
Concentration Measurement Uncertainties (MAU and MIU)
D.1 General
Estimate the minimum concentration measurement uncertainties for
the ith analyte (MAUi) and jth
interferant (MIUj) based on the spectral data in the
mth analytical region by comparing the analyte band area
in the analytical region (AAIim) and estimating or
measuring the noise level of the system (RMSEST or
RMSSm). (Note: For a single analytical region, the MAU or
MIU value is the concentration of the analyte or interferant for
which the band area is equal to the product of the analytical region
width (in wavenumbers) and the noise level of the system (in
absorbance units). If data from more than one analytical region are
used in the determination of an analyte concentration, the MAU or
MIU is the mean of the separate MAU or MIU values calculated for
each analytical region.)
D.2 Calculations
D.2.1 For each analytical region, set RMS = RMSSm if
measured ( attachment G of this addendum), or set RMS =
RMSEST if estimated ( attachment C of this addendum).
D.2.2 For each analyte associated with the analytical region,
calculate MAUim using equation D.1,
[GRAPHIC] [TIFF OMITTED] TP24MR98.013
D.2.3 If only the mth analytical region is used to
calculate the concentration of the ith analyte, set
MAUi = MAUim.
D.2.4 If more than one analytical region is used to calculate
the concentration of the ith analyte, set MAUi
equal to the weighted mean of the appropriate MAUim
values calculated above; the weight for each term in the mean is
equal to the fraction of the total wavenumber range used for the
calculation represented by each analytical region. Mathematically,
if the set of analytical regions employed is {m'}, then the MAU for
each analytical region is given by equation D.2.
[GRAPHIC] [TIFF OMITTED] TP24MR98.014
Where the weight Wik is defined for each term in the sum as
[GRAPHIC] [TIFF OMITTED] TP24MR98.015
[[Page 14235]]
D.2.5 Repeat sections D.2.1 through D.2.4 of this to calculate
the analogous values MIUj for the interferants j = 1 to
J. Replace the value (AUi) (DLi) in equation
D.1 with CPOTj/20; replace the value AAIim in
equation D.1 with IAIjm.
Attachment E to Addendum to Method 320--Determining Fractional
Reproducibility Uncertainties (FRU)
E.1 General
To estimate the reproducibility of the spectroscopic results of
the system, compare the CTS spectra recorded before and after
preparing the reference spectra. Compare the difference between the
spectra to their average band area. Perform the calculation for each
analytical region on the portions of the CTS spectra associated with
that analytical region.
E.2 Calculations
E.2.1 The CTS spectra {R1} consist of N spectra, denoted by
S1i, i=1, N. Similarly, the CTS spectra {R2} consist of N
spectra, denoted by S2i, i=1, N. Each Ski is
the spectrum of a single compound, where i denotes the compound and
k denotes the set {Rk} of which Ski is a member. Form the
spectra S3 according to S3i =
S2i-S1i for each i. Form the spectra
S4 according to S4i =
[S2i+S1i]/2 for each i.
E.2.2 Each analytical region m is associated with a portion of
the CTS spectra S2i and S1i, for a particular
i, with lower and upper wavenumber limits FFLm and
FFUm, respectively.
E.2.3 For each m and the associated i, calculate the band area
of S4i in the wavenumber range FFUm to
FFLm. Follow the guidelines of section B.1.2 of this
addendum for this band area calculation. Denote the result by
BAVm.
E.2.4 For each m and the associated i, calculate the RMSD of
S3i between the absorbance values and their mean in the
wavenumber range FFUm to FFLm. Denote the
result by SRMSm.
E.2.5 For each analytical region m, calculate FMm
using equation E.1,
[GRAPHIC] [TIFF OMITTED] TP24MR98.016
E.2.6 If only the mth analytical region is used to
calculate the concentration of the ith analyte, set
FRUi = FMm.
E.2.7 If a number pi of analytical regions are used to
calculate the concentration of the ith analyte, set
FRUi equal to the weighted mean of the appropriate
FMm values calculated according to section E.2.5.
Mathematically, if the set of analytical regions employed is {m'},
then FRUi is given by equation E.2,
[GRAPHIC] [TIFF OMITTED] TP24MR98.017
Where the Wik are calculated as described in
Attachment D of this addendum.
Attachment F to Addendum to Method 320--Determining Fractional
Calibration Uncertainties (FCU)
F.1 General
F.1.1 The concentrations yielded by the computerized analytical
program applied to each single-compound reference spectrum are
defined as the indicated standard concentrations (ISC's). The ISC
values for a single compound spectrum should ideally equal the
accepted standard concentration (ASC) for one analyte or
interferant, and should ideally be zero for all other compounds.
Variations from these results are caused by errors in the ASC
values, variations from the Beer's law (or modified Beer's law)
model used to determine the concentrations, and noise in the
spectra. When the first two effects dominate, the systematic nature
of the errors is often apparent and the analyst shall take steps to
correct them.
F.1.2 When the calibration error appears non-systematic, apply
the procedures of sections F.2.1 through F.2.3 of this appendix to
estimate the fractional calibration uncertainty (FCU) for each
compound. The FCU is defined as the mean fractional error between
the ASC and the ISC for all reference spectra with non-zero ASC for
that compound. The FCU for each compound shall be less than the
required fractional uncertainty specified in section 4.1 of this
addendum.
F.1.3 The computerized analytical programs shall also be
required to yield acceptably low concentrations for compounds with
ISC = 0 when applied to the reference spectra. The ISC of each
reference spectrum for each analyte or interferant shall not exceed
that compound's minimum measurement uncertainty (MAU or MIU).
F.2 Calculations
F.2.1 Apply each analytical program to each reference spectrum.
Prepare a similar table to that in Figure F.1 to present the ISC and
ASC values for each analyte and interferant in each reference
spectrum. Maintain the order of reference file names and compounds
employed in preparing Figure F.1.
F.2.2 For all reference spectra in Figure F.1, verify that the
absolute values of the ISC's are less than the compound's MAU (for
analytes) or MIU (for interferants).
F.2.3 For each analyte reference spectrum, calculate the
quantity (ASC-ISC)/ASC. For each analyte, calculate the mean of
these values (the FCUi for the ith analyte)
over all reference spectra. Prepare a similar table to that in
Figure F.2 to present the FCUi and analytical uncertainty
limit (AUi) for each analyte.
Figure F.1.--Presentation of Accepted Standard Concentrations (ASC's) and Indicated Standard Concentrations (ISC's)
--------------------------------------------------------------------------------------------------------------------------------------------------------
--------------------------------------------------------------------------------------------------------------------------------------------------------
Compound name Reference spectrum file ASC (ppm)
name
(5)ISC (ppm)
(5)Analytes Interferants
(5) i=1 I
(5) j=1 J
--------------------------------------------------------------------------------------------------------------------------------------------------------
--------------------------------------------------------------------------------------------------------------------------------------------------------
[[Page 14236]]
Figure F.2.--Presentation of Fractional Calibration Uncertainties
(FCU's) and Analytical Uncertainties (AU's)
------------------------------------------------------------------------
Analyte name FCU (%) AU (%)
------------------------------------------------------------------------
------------------------------------------------------------------------
Attachment G to Addendum to Method 320--Measuring Noise Levels
G.1 General
The root-mean-square (RMS) noise level is the standard measure
of noise. The RMS noise level of a contiguous segment of a spectrum
is the RMSD between the absorbance values that form the segment and
the mean value of the segment (see appendix A of this addendum).
G.2 Calculations
G.2.1 Evacuate the absorption cell or fill it with UPC grade
nitrogen at approximately one atmosphere total pressure.
G.2.2 Record two single beam spectra of signal integration
period tSS.
G.2.3 Form the double beam absorption spectrum from these two
single beam spectra, and calculate the noise level RMSSm
in the M analytical regions.
Attachment H of Addendum to Method 320--Determining Sample Absorption
Pathlength (LS) and Fractional Analytical Uncertainty (FAU)
H.1 General
Reference spectra recorded at absorption pathlength
(LR), gas pressure (PR), and gas absolute
temperature (TR) may be used to determine analyte
concentrations in samples whose spectra are recorded at conditions
different from that of the reference spectra, i.e., at absorption
pathlength (LS), absolute temperature (TS),
and pressure (PS). This appendix describes the
calculations for estimating the fractional uncertainty (FAU) of this
practice. It also describes the calculations for determining the
sample absorption pathlength from comparison of CTS spectra, and for
preparing spectra for further instrumental and procedural checks.
H.1.1 Before sampling, determine the sample absorption
pathlength using least squares analysis. Determine the ratio
LS/LR by comparing the spectral sets {R1} and
{R3}, which are recorded using the same CTS at LS and
LR, and TS and TR, but both at
PR.
H.1.2 Determine the fractional analysis uncertainty (FAU) for
each analyte by comparing a scaled CTS spectral set, recorded at
LS, TS, and PS, to the CTS
reference spectra of the same gas, recorded at LR,
TR, and PR. Perform the quantitative
comparison after recording the sample spectra, based on band areas
of the spectra in the CTS absorbance band associated with each
analyte.
H.2 Calculations
H.2.1 Absorption Pathlength Determination. Perform and
document separate linear baseline corrections to each analytical
region in the spectral sets {R1} and {R3}. Form a one-dimensional
array AR containing the absorbance values from all
segments of {R1} that are associated with the analytical regions;
the members of the array are ARi, i = 1, n. Form a
similar one-dimensional array AS from the absorbance
values in the spectral set {R3}; the members of the array are
ASi, i = 1, n. Based on the model AS =
rAR + E, determine the least-squares estimate of r', the
value of r which minimizes the square error E \2\. Calculate the
sample absorption pathlength, LS, using equation H.1,
LS = r'(TS/TR)LR (Eq.
320-H.)
H.2.2 Fractional Analysis Uncertainty. Perform and document
separate linear baseline corrections to each analytical region in
the spectral sets {R1} and {R4}. Form the arrays AS and
AR as described in section H.2.1 of this appendix, using
values from {R1} to form AR, and values from {R4} to form
AS. Calculate NRMSE and IAAV using
equations H.2 and H.3,
[GRAPHIC] [TIFF OMITTED] TP24MR98.018
[GRAPHIC] [TIFF OMITTED] TP24MR98.019
The fractional analytical uncertainty, FAU, is given by equation
H.4,
[GRAPHIC] [TIFF OMITTED] TP24MR98.020
Attachment I to Addendum to Method 320--Determining Fractional Model
Uncertainties (FMU)
I.1 General
To prepare analytical programs for FTIR analyses, the sample
constituents must first be assumed. The calculations in this,
appendix, based upon a simulation of the sample spectrum, shall be
used to verify the appropriateness of these assumptions. The
simulated spectra consist of the sum of single compound reference
spectra scaled to represent their contributions to the sample
absorbance spectrum; scaling factors are based on the indicated
standard concentrations (ISC) and measured (sample) analyte and
interferant concentrations, the sample and reference absorption
pathlengths, and the sample and reference gas pressures. No band-
shape correction for differences in the temperature of the sample
and reference spectra gases is made; such errors are included in the
FMU estimate. The actual and simulated sample spectra are
quantitatively compared to determine the fractional model
uncertainty; this comparison uses the reference spectra band areas
and residuals in the difference spectrum formed from the actual and
simulated sample spectra.
I.2 Calculations
I.2.1 For each analyte (with scaled concentration
RSAi), select a reference spectrum SAi with
indicated standard concentration ISCi. Calculate the
scaling factors, RAi, using equation I.1,
[GRAPHIC] [TIFF OMITTED] TP24MR98.021
Form the spectra SACi by scaling each SAi
by the factor RAi.
I.2.2 For each interferant, select a reference spectrum
SIk with indicated standard concentration
ISCk. Calculate the scaling factors, RIk,
using equation I.2,
[[Page 14237]]
[GRAPHIC] [TIFF OMITTED] TP24MR98.022
Form the spectra SICk by scaling each SIk
by the factor RIk.
I.2.3 For each analytical region, determine by visual
inspection which of the spectra SACi and SICk
exhibit absorbance bands within the analytical region. Subtract each
spectrum SACi and SICk exhibiting absorbance
from the sample spectrum SS to form the spectrum
SUBS. To save analysis time and to avoid the introduction
of unwanted noise into the subtracted spectrum, it is recommended
that the calculation be made (1) only for those spectral data points
within the analytical regions, and (2) for each analytical region
separately using the original spectrum SS.
I.2.4 For each analytical region m, calculate the RMSD of
SUBS between the absorbance values and their mean in the
region FFUm to FFLm. Denote the result by
RMSSm.
I.2.5 For each analyte i, calculate FMm, using equation I.3,
[GRAPHIC] [TIFF OMITTED] TP24MR98.023
for each analytical region associated with the analyte.
I.2.6 If only the mth analytical region is used to
calculate the concentration of the ith analyte, set
FMUi=FMm.
I.2.7 If a number of analytical regions are used to calculate
the concentration of the ith analyte, set FMi
equal to the weighted mean of the appropriate FMm values
calculated using equation I-3. Mathematically, if the set of
analytical regions employed is {m'}, then the fractional model
uncertainty, FMU, is given by equation I.4,
[GRAPHIC] [TIFF OMITTED] TP24MR98.024
Where Wik is calculated as described in Attachment D
of this addendum.
Attachment J to Addendum to Method 320--Determining Overall
Concentration Uncertainties (OCU)
The calculations in this addendum estimate the measurement
uncertainties for various FTIR measurements. The lowest possible
overall concentration uncertainty (OCU) for an analyte is its MAU
value, which is an estimate of the absolute concentration
uncertainty when spectral noise dominates the measurement error.
However, if the product of the largest fractional concentration
uncertainty (FRU, FCU, FAU, or FMU) and the measured concentration
of an analyte exceeds the MAU for the analyte, then the OCU is this
product. In mathematical terms, set OFUi =
MAX{FRUi, FCUi, FAUi,
FMUi} and OCUi =
MAX{RSAi*OFUi, MAUi}.
Method 321--Measurement of Gaseous Hydrogen Chloride Emissions At
Portland Cement Kilns by Fourier Transform Infrared (FTIR) Spectroscopy
1.0 Introduction
This method should be performed by those persons familiar with
the operation of Fourier Transform Infrared (FTIR) instrumentation
in the application to source sampling. This document describes the
sampling procedures for use in the application of FTIR spectrometry
for the determination of vapor phase hydrogen chloride (HCl)
concentrations both before and after particulate matter control
devices installed at portland cement kilns. A procedure for analyte
spiking is included for quality assurance. This method is considered
to be self validating provided that the requirements listed in
section 9 of this method are followed. The analytical procedures for
interpreting infrared spectra from emission measurements are
described in the ``Protocol For The Use of Extractive Fourier
Transform Infrared (FTIR) Spectrometry in Analyses of Gaseous
Emissions From Stationary Industrial Sources'', included as an
addendum to proposed Method 320 of this appendix (hereafter referred
to as the ``FTIR Protocol''). References 1 and 2 describe the use of
FTIR spectrometry in field measurements. Sample transport presents
the principal difficulty in directly measuring HCl emissions. This
identical problem must be overcome by any extractive measurement
method. HCl is reactive and water soluble. The sampling system must
be adequately designed to prevent sample condensation in the system.
1.1 Scope and Application.
This method is specifically designed for the application of FTIR
Spectrometry in extractive measurements of gaseous HCl
concentrations in portland cement kiln emissions.
1.2 Applicability. This method applies to the measurement of
HCl [CAS No. 7647-01-0]. This method can be applied to the
determination of HCl concentrations both before and after
particulate matter control devices installed at portland cement
manufacturing facilities. This method applies to either continuous
flow through measurement (with isolated sample analysis) or grab
sampling (batch analysis). HCl is measured using the mid-infrared
spectral region for analysis (about 400 to 4000 cm-1 or
25 to 2.5 m). Table 1 lists the suggested analytical region
for quantification of HCl taking the interference from water vapor
into consideration.
Table 1.--Example Analytical Region for HCl
------------------------------------------------------------------------
Analytical Potential
Compound region (cm-1) interferants
------------------------------------------------------------------------
Hydrogen chloride................. 2679-2840 Water.
------------------------------------------------------------------------
1.3 Method Range and Sensitivity.
1.3.1 The analytical range is determined by the instrumental
design and the composition of the gas stream. For practical purposes
there is no upper limit to the range because the pathlength may be
reduced or the sample may be diluted. The lower detection range
depends on (1) the absorption coefficient of the compound in the
analytical frequency region, (2) the spectral resolution, (3) the
interferometer sampling time, (4) the detector sensitivity and
response, and (5) the absorption pathlength.
1.3.2 The practical lower quantification range is usually
higher than the instrument sensitivity allows and is dependent upon
(1) the presence of interfering species in the exhaust gas including
H2O, CO2, and SO2, (2) analyte
losses in the sampling system, (3) the optical alignment of the gas
cell and transfer optics, and (4) the quality of the reflective
surfaces in the cell (cell throughput). Under typical test
conditions (moisture content of up to 30% and CO2
concentrations from 1 to 15 percent), a 22 meter path length cell
with a suitable sampling system may achieve a lower quantification
range of from 1 to 5 ppm for HCl.
1.4 Data Quality Objectives.
1.4.1 In designing or configuring the analytical system, data
quality is determined by measuring of the root mean square deviation
(RMSD) of the absorbance values within a chosen spectral
(analytical) region. The RMSD provides an indication of the signal-
to-noise ratio (S/N) of the spectral baseline. Appendix D of the
FTIR Protocol (the addendum to Method 320 of this appendix) presents
a discussion of the relationship between the RMSD, lower detection
limit, DLi, and analytical uncertainty, AUi.
It is important to consider the target analyte quantification limit
when performing testing with FTIR instrumentation, and to optimize
the system to achieve the desired detection limit.
1.4.2 Data quality is determined by measuring the root mean
square (RMS) noise level in each analytical spectral region
(appendix C of the FTIR Protocol). The RMS noise is defined as the
root mean square deviation (RMSD) of the absorbance values in an
analytical region from the mean absorbance value in the same region.
Appendix D of the FTIR Protocol defines the minimum analyte
uncertainty (MAU), and how the RMSD is used to calculate the MAU.
The MAUim is the minimum concentration of the ith analyte
in the mth analytical region for which the analytical uncertainty
limit can be maintained. Table 2 to this method presents example
values of AU and MAU using the analytical region presented in Table
1 to this method.
[[Page 14238]]
TABLE 2.--Example Pre-Test Protocol Calculations for Hydrogen Chloride
------------------------------------------------------------------------
HCl
------------------------------------------------------------------------
Reference concentration (ppm-meters)/K.................. 11.2
Reference Band Area..................................... 2.881
DL (ppm-meters)/K....................................... 0.1117
AU...................................................... 0.2
CL (DL x AU)............................................ 0.02234
FL (cm-1)............................................... 2679.83
FU (cm-1)............................................... 2840.93
FC (cm-1)............................................... 2760.38
AAI (ppm-meters)/K...................................... 0.06435
RMSD.................................................... 2.28 E-03
MAU (ppm-meters)/K...................................... 1.28E-01
MAU ppm at 22 meters and 250 deg.F..................... 0.2284
------------------------------------------------------------------------
2.0 Summary of Method
2.1 Principle.
See Method 320 of this appendix. HCl can also undergo rotation
transitions by absorbing energy in the far-infrared spectral region.
The rotational transitions are superimposed on the vibrational
fundamental to give a series of lines centered at the fundamental
vibrational frequency, 2885 cm-1. The frequencies of
absorbance and the pattern of rotational/vibrational lines are
unique to HCl. When this distinct pattern is observed in an infrared
spectrum of an unknown sample, it unequivocally identifies HCl as a
component of the mixture. The infrared spectrum of HCl is very
distinctive and cannot be confused with the spectrum of any other
compound. See Reference 6.
2.2 Sampling and Analysis. See Method 320 of this appendix.
2.3 Operator Requirements. The analyst must have knowledge of
spectral patterns to choose an appropriate absorption path length or
determine if sample dilution is necessary. The analyst should also
understand FTIR instrument operation well enough to choose
instrument settings that are consistent with the objectives of the
analysis.
3.0 Definitions
See A of the FTIR Protocol.
4.0 Interferences
This method will not measure HCl under conditions: (1) where the
sample gas stream can condense in the sampling system or the
instrumentation, or (2) where a high moisture content sample
relative to the analyte concentrations imparts spectral interference
due to the water vapor absorbance bands. For measuring HCl the first
(sampling) consideration is more critical. Spectral interference
from water vapor is not a significant problem except at very high
moisture levels and low HCl concentrations.
4.1 Analytical Interferences. See Method 320 of this appendix.
4.1.1 Background Interferences. See Method 320 of this
appendix.
4.1.2 Spectral interferences. Water vapor can present spectral
interference for FTIR gas analysis of HCl. Therefore, the water
vapor in the spectra of kiln gas samples must be accounted for. This
means preparing at least one spectrum of a water vapor sample where
the moisture concentration is close to that in the kiln gas.
4.2 Sampling System Interferences. The principal sampling
system interferant for measuring HCl is water vapor. Steps must be
taken to ensure that no condensation forms anywhere in the probe
assembly, sample lines, or analytical instrumentation. Cold spots
anywhere in the sampling system must be avoided. The extent of
sampling system bias in the FTIR analysis of HCl depends on
concentrations of potential interferants, moisture content of the
gas stream, temperature of the gas stream, temperature of sampling
system components, sample flow rate, and reactivity of HCl with
other species in the gas stream (e.g., ammonia). For measuring HCl
in a wet gas stream the temperatures of the gas stream, sampling
components, and the sample flow rate are of primary importance.
Analyte spiking with HCl is performed to demonstrate the integrity
of the sampling system for transporting HCl vapor in the flue gas to
the FTIR instrument. See section 9 of this method for a complete
description of analyte spiking.
5.0 Safety
5.1 Hydrogen chloride vapor is corrosive and can cause
irritation or severe damage to respiratory system, eyes and skin.
Exposure to this compound should be avoided.
5.2 This method may involve sampling at locations having high
positive or negative pressures, or high concentrations of hazardous
or toxic pollutants, and can not address all safety problems
encountered under these diverse sampling conditions. It is the
responsibility of the tester(s) to ensure proper safety and health
practices, and to determine the applicability of regulatory
limitations before performing this test method. Leak-check
procedures are outlined in section 8.2 of Method 320 of this .
6.0 Equipment and Supplies.
(Note: Mention of trade names or specific products does not
constitute endorsement by the Environmental Protection Agency.)
6.1 FTIR Spectrometer and Detector. An FTIR Spectrometer system
(interferometer, transfer optics, gas cell and detector) having the
capability of measuring HCl to the predetermined minimum detectable
level required (see section 4.1.3 of the FTIR Protocol). The system
must also include an accurate means to control and/or measure the
temperature of the FTIR gas analysis cell, and a personal computer
with compatible software that provides real-time updates of the
spectral profile during sample and spectral collection.
6.2 Pump. Capable of evacuating the FTIR cell volume to 1 Torr
(133.3 Pascals) within two minutes (for batch sample analysis).
6.3 Mass Flow Meters/Controllers. To accurately measure analyte
spike flow rate, having the appropriate calibrated range and a
stated accuracy of 2 percent of the absolute
measurement value. This device must be calibrated with the major
component of the calibration/spike gas (e.g., nitrogen) using an
NIST traceable bubble meter or equivalent. Single point calibration
checks should be performed daily in the field. When spiking HCl, the
mass flow meter/controller should be thoroughly purged before and
after introduction of the gas to prevent corrosion of the interior
parts.
6.4 Polytetrafluoroethane tubing. Diameter and length suitable
to connect cylinder regulators.
6.5 Stainless Steel tubing. Type 316 of appropriate length and
diameter for heated connections.
6.6 Gas Regulators. Purgeable HCl regulator.
6.7 Pressure Gauge. Capable of measuring pressure from 0 to
1000 Torr (133.3 Pa=1 Torr) within 5 percent.
6.8 Sampling Probe. Glass, stainless steel or other appropriate
material of sufficient length and physical integrity to sustain
heating, prevent adsorption of analytes and capable of reaching gas
sampling point.
6.9 Sampling Line. Heated 180 deg.C (360 deg.F) and
fabricated of either stainless steel, polytetrafluoroethane or other
material that prevents adsorption of HCl and transports effluent to
analytical instrumentation. The extractive sample line must have the
capability to transport sample gas to the analytical components as
well as direct heated calibration spike gas to the calibration
assembly located at the sample probe. It is important to minimize
the length of heated sample line.
6.10 Particulate Filters. A sintered stainless steel filter
rated at 20 microns or greater may be placed at the inlet of the
probe (for removal of large particulate matter). A heated filter
(Balston or equivalent) rated at 1 micron is necessary
for primary particulate matter removal, and shall be placed
immediately after the heated probe. The filter/filter holder
temperature should be maintained at 180 deg.C (360 deg.F).
6.11 Calibration/Analyte Spike Assembly. A heated three-way
valve assembly (or equivalent) to introduce surrogate spikes into
the sampling system at the outlet of the probe before the primary
particulate filter.
6.12 Sample Extraction Pump. A leak-free heated head pump
(KNF Neuberger or equivalent) capable of extracting
sample effluent through entire sampling system at a rate which
prevents analyte losses and minimizes analyzer response time. The
pump should have a heated by-pass and may be placed either before
the FTIR instrument or after. If the sample pump is located upstream
of the FTIR instrument, it must be fabricated from materials non-
reactive to HCl. The sampling system and FTIR measurement system
shall allow the operator to obtain at least six sample spectra
during a one-hour period.
6.13 Barometer. For measurement of barometric pressure.
6.14 Gas Sample Manifold. A distribution manifold having the
capabilities listed in sections 6.14.1 through 6.14.4;
6.14.1 Delivery of calibration gas directly to the analytical
instrumentation;
6.14.2 Delivery of calibration gas to the sample probe (system
calibration or analyte spike) via a heated traced sample line;
6.14.3 Delivery of sample gas (kiln gas, spiked kiln gas, or
system calibrations) to the analytical instrumentation;
6.14.4 Delivery (optional) of a humidified nitrogen sample
stream.
[[Page 14239]]
6.15 Flow Measurement Device. Type S Pitot tube (or equivalent)
and Magnahelic set for measurement of volumetric flow
rate.
7.0 Reagents and Standards
HCl can be purchased in a standard compressed gas cylinder. The
most stable HCl cylinder mixture available has a concentration
certified at 5 percent. Such a cylinder is suitable for
performing analyte spiking because it will provide reproducible
samples. The stability of the cylinder can be monitored over time by
periodically performing direct FTIR analysis of cylinder samples. It
is recommended that a 10-50 ppm cylinder of HCl be prepared having
from 2-5 ppm SF6 as a tracer compound. (See sections 7.1 through 7.3
of Method 320 of this for a complete description of the use of
existing HCl reference spectra. See section 9.1 of Method 320 of
this for a complete discussion of standard concentration selection.)
8.0 Sample Collection, Preservation and Storage
See also Method 320 of this appendix.
8.1 Pretest. A screening test is ideal for obtaining proper
data that can be used for preparing analytical program files.
Information from literature surveys and source personnel is also
acceptable. Information about the sampling location and gas stream
composition is required to determine the optimum sampling system
configuration for measuring HCl. Determine the percent moisture of
the kiln gas by Method 4 of appendix A to part 60 of this chapter or
by performing a wet bulb/dry bulb measurement. Perform a preliminary
traverse of the sample duct or stack and select the sampling
point(s). Acquire an initial spectrum and determine the optimum
operational pathlength of the instrument.
8.2 Leak-Check. See Method 320 of this appendix, section 8.2
for direction on performing leak-checks.
8.3 Background Spectrum. See Method 320 of this appendix,
section 8.5 for direction in background spectral acquisition.
8.4 Pre-Test Calibration Transfer Standard (Direct Instrument
Calibration). See Method 320 of this appendix, section 8.3 for
direction in CTS spectral acquisition.
8.5 Pre-Test System Calibration. See Method 320 of this
appendix, sections 8.6.1 through 8.6.2 for direction in performing
system calibration.
8.6 Sampling.
8.6.1 Extractive System. An extractive system maintained at 180
deg.C (360 deg.F) or higher which is capable of directing a total
flow of at least 12 L/min to the sample cell is required (References
1 and 2). Insert the probe into the duct or stack at a point
representing the average volumetric flow rate and 25 percent of the
cross sectional area. Co-locate an appropriate flow monitoring
device with the sample probe so that the flow rate is recorded at
specified time intervals during emission testing (e.g., differential
pressure measurements taken every 10 minutes during each run).
8.6.2 Batch Samples. Evacuate the absorbance cell to 5 Torr (or
less) absolute pressure before taking first sample. Fill the cell
with kiln gas to ambient pressure and record the infrared spectrum,
then evacuate the cell until there is no further evidence of
infrared absorption. Repeat this procedure, collecting a total of
six separate sample spectra within a 1-hour period.
8.6.3 Continuous Flow Through Sampling. Purge the FTIR cell
with kiln gas for a time period sufficient to equilibrate the entire
sampling system and FTIR gas cell. The time required is a function
of the mechanical response time of the system (determined by
performing the system calibration with the CTS gas or equivalent),
and by the chemical reactivity of the target analytes. If the
effluent target analyte concentration is not variable, observation
of the spectral up-date of the flowing gas sample should be
performed until equilibration of the sample is achieved. Isolate the
gas cell from the sample flow by directing the purge flow to vent.
Record the spectrum and pressure of the sample gas. After spectral
acquisition, allow the sample gas to purge the cell with at least
three volumes of kiln gas. The time required to adequately purge the
cell with the required volume of gas is a function of (1) cell
volume, (2) flow rate through the cell, and (3) cell design. It is
important that the gas introduction and vent for the FTIR cell
provides a complete purge through the cell.
8.6.4 Continuous Sampling. In some cases it is possible to
collect spectra continuously while the FTIR cell is purged with
sample gas. The sample integration time, tss, the sample
flow rate through the gas cell, and the sample integration time must
be chosen so that the collected data consist of at least 10 spectra
with each spectrum being of a separate cell volume of flue gas.
Sampling in this manner may only be performed if the native source
analyte concentrations do not affect the test results.
8.7 Sample Conditioning
8.7.1 High Moisture Sampling. Kiln gas emitted from wet process
cement kilns may contain 3- to 40 percent moisture. Zinc selenide
windows or the equivalent should be used when attempting to analyze
hot/wet kiln gas under these conditions to prevent dissolution of
water soluble window materials (e.g., KBr).
8.7.2 Sample Dilution. The sample may be diluted using an in-
stack dilution probe, or an external dilution device provided that
the sample is not diluted below the instrument's quantification
range. As an alternative to using a dilution probe, nitrogen may be
dynamically spiked into the effluent stream in the same manner as
analyte spiking. A constant dilution rate shall be maintained
throughout the measurement process. It is critical to measure and
verify the exact dilution ratio when using a dilution probe or the
nitrogen spiking approach. Calibrating the system with a calibration
gas containing an appropriate tracer compound will allow
determination of the dilution ratio for most measurement systems.
The tester shall specify the procedures used to determine the
dilution ratio, and include these calibration results in the report.
8.8 Sampling QA, Data Storage and Reporting. See the FTIR
Protocol. Sample integration times shall be sufficient to achieve
the required signal-to-noise ratio, and all sample spectra should
have unique file names. Two copies of sample interferograms and
processed spectra will be stored on separate computer media. For
each sample spectrum the analyst must document the sampling
conditions, the sampling time (while the cell was being filled), the
time the spectrum was recorded, the instrumental conditions (path
length, temperature, pressure, resolution, integration time), and
the spectral file name. A hard copy of these data must be maintained
until the test results are accepted.
8.9 Signal Transmittance. Monitor the signal transmittance
through the instrumental system. If signal transmittance (relative
to the background) drops below 95 percent in any spectral region
where the sample does not absorb infrared energy, then a new
background spectrum must be obtained.
8.10 Post-test CTS. After the sampling run completion, record
the CTS spectrum. Analysis of the spectral band area used for
quantification from pre-and post-test CTS spectra should agree to
within 5 percent or corrective action must be taken.
8.11 Post-test QA. The sample spectra shall be inspected
immediately after the run to verify that the gas matrix composition
was close to the assumed gas matrix, (this is necessary to account
for the concentrations of the interferants for use in the analytical
analysis programs), and to confirm that the sampling and
instrumental parameters were appropriate for the conditions
encountered.
9.0 Quality Control
Use analyte spiking to verify the effectiveness of the sampling
system for the target compounds in the actual kiln gas matrix. QA
spiking shall be performed before and after each sample run. QA
spiking shall be performed after the pre-and post-test CTS direct
and system calibrations. The system biases calculated from the pre-
and post-test dynamic analyte spiking shall be within 30
percent for the spiked surrogate analytes for the measurements to be
considered valid. See sections 9.3.1 through 9.3.2 for the requisite
calculations. Measurement of the undiluted spike (direct-to-cell
measurement) involves sending dry, spike gas to the FTIR cell,
filling the cell to 1 atmosphere and obtaining the spectrum of this
sample. The direct-to-cell measurement should be performed before
each analyte spike so that the recovery of the dynamically spiked
analytes may be calculated. Analyte spiking is only effective for
assessing the integrity of the sampling system when the
concentration of HCl in the source does not vary substantially. Any
attempt to quantify an analyte recovery in a variable concentration
matrix will result in errors in the expected concentration of the
spiked sample. If the kiln gas target analyte concentrations vary by
more than 5 percent (or 5 ppm, whichever is greater) in
the time required to acquire a sample spectrum, it may be necessary
to: (1) use a dual sample probe approach, (2) use two independent
FTIR measurement systems, (3) use alternate QA/QC procedures, or (4)
postpone testing until stable emission concentrations are achieved.
(See section 9.2.3 of this method).
[[Page 14240]]
It is recommended that a laboratory evaluation be performed before
attempting to employ this method under actual field conditions. The
laboratory evaluation shall include (1) performance of all
applicable calculations in section 4 of the FTIR Protocol; (2)
simulated analyte spiking experiments in dry (ambient) and
humidified sample matrices using HCl; and (3) performance of bias
(recovery) calculations from analyte spiking experiments. It is not
necessary to perform a laboratory evaluation before every field
test. The purpose of the laboratory study is to demonstrate that the
actual instrument and sampling system configuration used in field
testing meets the requirements set forth in this method.
9.1 Spike Materials. Perform analyte spiking with an HCl
standard to demonstrate the integrity of the sampling system.
9.1.1 An HCl standard of approximately 50 ppm in a balance of
ultra pure nitrogen is recommended. The SF6 (tracer)
concentration shall be 2 to 5 ppm depending upon the measurement
pathlength. The spike ratio (spike flow/total flow) shall be no
greater than 1:10, and an ideal spike concentration should
approximate the native effluent concentration.
9.1.2 The ideal spike concentration may not be achieved because
the target concentration cannot be accurately predicted prior to the
field test, and limited calibration standards will be available
during testing. Therefore, practical constraints must be applied
that allow the tester to spike at an anticipated concentration. For
these tests, the analyte concentration contributed by the HCl
standard spike should be 1 to 5 ppm or should more closely
approximate the native concentration if it is greater.
9.2 Spike Procedure
9.2.1 A spiking/sampling apparatus is shown in Figure 2.
Introduce the spike/tracer gas mixture at a constant flow
(2 percent) rate at approximately 10 percent of the
total sample flow. (For example, introduce the surrogate spike at 1
L/min 20 cc/min, into a total sample flow rate of 10 L/
min). The spike must be pre-heated before introduction into the
sample matrix to prevent a localized condensation of the gas stream
at the spike introduction point. A heated sample transport line(s)
containing multiple transport tubes within the heated bundle may be
used to spike gas up through the sampling system to the spike
introduction point. Use a calibrated flow device (e.g., mass flow
meter/controller), to monitor the spike flow as indicated by a
calibrated flow meter or controller, or alternately, the
SF6 tracer ratio may be calculated from the direct
measurement and the diluted measurement. It is often desirable to
use the tracer approach in calculating the spike/total flow ratio
because of the difficulty in accurately measuring hot/wet total
flow. The tracer technique has been successfully used in past
validation efforts (Reference 1).
9.2.2 Perform a direct-to-cell measurement of the dry,
undiluted spike gas. Introduce the spike directly to the FTIR cell,
bypassing the sampling system. Fill cell to 1 atmosphere and collect
the spectrum of this sample. Ensure that the spike gas has
equilibrated to the temperature of the measurement cell before
acquisition of the spectra. Inspect the spectrum and verify that the
gas is dry and contains negligible CO2. Repeat the
process to obtain a second direct-to-cell measurement. Analysis of
spectral band areas for HCl from these duplicate measurements should
agree to within 5 percent of the mean.
9.2.3 Analyte Spiking. Determine whether the kiln gas contains
native concentrations of HCl by examination of preliminary spectra.
Determine whether the concentration varies significantly with time
by observing a continuously up-dated spectrum of sample gas in the
flow-through sampling mode. If the concentration varies by more than
5 percent during the period of time required to acquire
a spectra, then an alternate approach should be used. One alternate
approach uses two sampling lines to convey sample to the gas
distribution manifold. One of the sample lines is used to
continuously extract unspiked kiln gas from the source. The other
sample line serves as the analyte spike line. One FTIR system can be
used in this arrangement. Spiked or unspiked sample gas may be
directed to the FTIR system from the gas distribution manifold, with
the need to purge only the components between the manifold and the
FTIR system. This approach minimizes the time required to acquire an
equilibrated sample of spiked or unspiked kiln gas. If the source
varies by more than 5 percent (or 5 ppm, whichever is
greater) in the time it takes to switch from the unspiked sample
line to the spiked sample line, then analyte spiking may not be a
feasible means to determine the effectiveness of the sampling system
for the HCl in the sample matrix. A second alternative is to use two
completely independent FTIR measurement systems. One system would
measure unspiked samples while the other system would measure the
spiked samples. As a last option, (where no other alternatives can
be used) a humidified nitrogen stream may be generated in the field
which approximates the moisture content of the kiln gas. Analyte
spiking into this humidified stream can be employed to assure that
the sampling system is adequate for transporting the HCl to the FTIR
instrumentation.
9.2.3.1 Adjust the spike flow rate to approximately 10 percent
of the total flow by metering spike gas through a calibrated mass
flowmeter or controller. Allow spike flow to equilibrate within the
sampling system before analyzing the first spiked kiln gas samples.
A minimum of two consecutive spikes are required. Analysis of the
spectral band area used for quantification should agree to within
5 percent or corrective action must be taken.
9.2.3.2 After QA spiking is completed, the sampling system
components shall be purged with nitrogen or dry air to eliminate
traces of the HCl compound from the sampling system components.
Acquire a sample spectra of the nitrogen purge to verify the absence
of the calibration mixture.
9.2.3.3 Analyte spiking procedures must be carefully executed
to ensure that meaningful measurements are achieved. The
requirements of sections 9.2.3.3.1 through 9.2.3.3.4 shall be met.
9.2.3.3.1 The spike must be in the vapor phase, dry, and heated
to (or above) the kiln gas temperature before it is introduced to
the kiln gas stream.
9.2.3.3.2 The spike flow rate must be constant and accurately
measured.
9.2.3.3.3 The total flow must also be measured continuously and
reliably or the dilution ratio must otherwise be verified before and
after a run by introducing a spike of a non-reactive, stable
compound (i.e., tracer).
9.2.3.3.4 The tracer must be inert to the sampling system
components, not contained in the effluent gas, and readily detected
by the analytical instrumentation. Sulfur hexafluoride
(SF6) has been used successfully (References 1 and 2) for
this purpose.
9.3 Calculations
9.3.1 Recovery. Calculate the percent recovery of the spiked
analytes using equations 1 and 2.
%R = (Sm/Ce) x 100 (Eq. 321-1).
Sm = Mean concentration of the analyte spiked effluent
samples (observed).
Ce = Expected concentration of the spiked samples
(theoretical).
Ce = DfCs + Su (1-
Df) (Eq. 321-2)
Df = dilution Factor (Spike flow/Total flow). total flow
= spike flow plus effluent flow.
Cs = cylinder concentration of spike gas.
Su = native concentration of analytes in unspiked
samples.
The spike dilution factor may be confirmed by measuring the
total flow and the spike flow directly. Alternately, the spike
dilution can be verified by comparing the concentration of the
tracer compound in the spiked samples (diluted) to the tracer
concentration in the direct (undiluted) measurement of the spike
gas.
If SF6 is the tracer gas, then
Df = [SF6]spike/
[SF6]direct (Eq. 321-3)
[SF6]spike = the diluted SF6 concentration
measured in a spiked sample.
[SF6]direct = the SF6 concentration
measured directly.
9.3.2 Bias. The bias may be determined by the difference
between the observed spike value and the expected response (i.e.,
the equivalent concentration of the spiked material plus the analyte
concentration adjusted for spike dilution). Bias is defined by
section 6.3.1 of EPA Method 301 of this (Reference 8) as,
B = Sm -- Ce (Eq. 321-4)
where:
B = Bias at spike level.
Sm = Mean concentration of the analyte spiked samples.
Ce = Expected concentration of the analyte in spiked
samples.
Acceptable recoveries for analyte spiking are 30
percent. Application of correction factors to the data based upon
bias and recovery calculations is subject to the approval of the
Administrator.
10.0 Calibration and Standardization
10.1 Calibration transfer standards (CTS). The EPA Traceability
Protocol gases or NIST traceable standards, with a minimum accuracy
of 2 percent shall be used. For
[[Page 14241]]
other requirements of the CTS, see the FTIR Protocol section 4.5.
10.2 Signal-to-Noise Ratio (S/N). The S/N shall be less than
the minimum acceptable measurement uncertainty in the analytical
regions to be used for measuring HCl.
10.3 Absorbance Pathlength. Verify the absorbance path length
by comparing CTS spectra to reference spectra of the calibration
gas(es).
10.4 Instrument Resolution. Measure the line width of
appropriate CTS band(s) to verify instrumental resolution.
10.5 Apodization Function. Choose the appropriate apodization
function. Determine any appropriate mathematical transformations
that are required to correct instrumental errors by measuring the
CTS. Any mathematical transformations must be documented and
reproducible. Reference 9 provides additional information about FTIR
instrumentation.
11.0 Analytical Procedure
A full description of the analytical procedures is given in
sections 4.6--4.11, sections 5, 6, and 7, and the appendices of the
FTIR Protocol. Additional description of quantitative spectral
analysis is provided in References 10 and 11.
12.0 Data Analysis and Calculations
Data analysis is performed using appropriate reference spectra
whose concentrations can be verified using CTS spectra. Various
analytical programs (References 10 and 11) are available to relate
sample absorbance to a concentration standard. Calculated
concentrations should be verified by analyzing spectral baselines
after mathematically subtracting scaled reference spectra from the
sample spectra. A full description of the data analysis and
calculations may be found in the FTIR Protocol (sections 4.0, 5.0,
6.0 and appendices).
12.1 Calculated concentrations in sample spectra are corrected
for differences in absorption pathlength between the reference and
sample spectra by
Ccorr = (Lr/Ls) x (Ts/
Tr) x (Ccalc) (Eq. 321-5)
Where:
Ccorr = The pathlength corrected concentration.
Ccalc = The initial calculated concentration (output of
the multicomponent analysis program designed for the compound).
Lr = The pathlength associated with the reference
spectra.
Ls = The pathlength associated with the sample spectra.
Ts = The absolute temperature (K) of the sample gas.
Tr = The absolute temperature (K) at which reference
spectra were recorded.
12.2 The temperature correction in equation 5 is a volumetric
correction. It does not account for temperature dependence of
rotational-vibrational relative line intensities. Whenever possible,
the reference spectra used in the analysis should be collected at a
temperature near the temperature of the FTIR cell used in the test
to minimize the calculated error in the measurement (FTIR Protocol,
appendix D). Additionally, the analytical region chosen for the
analysis should be sufficiently broad to minimize errors caused by
small differences in relative line intensities between reference
spectra and the sample spectra.
13.0 Method Performance
A description of the method performance may be found in the FTIR
Protocol. This method is self validating provided the results meet
the performance specification of the QA spike in sections 9.0
through 9.3 of this method.
14.0 Pollution Prevention
This is a gas phase measurement. Gas is extracted from the
source, analyzed by the instrumentation, and discharged through the
instrument vent.
15.0 Waste Management
Gas standards of HCl are handled according to the instructions
enclosed with the material safety data sheet.
16.0 References
1. ``Laboratory and Field Evaluation of a Methodology for
Determination of Hydrogen Chloride Emissions From Municipal and
Hazardous Waste Incinerators,'' S. C. Steinsberger and J. H.
Margeson. Prepared for U.S. Environmental Protection Agency,
Research Triangle Park, NC. NTIS Report No. PB89-220586. (1989).
2. ``Evaluation of HCl Measurement Techniques at Municipal and
Hazardous Waste Incinerators,'' S.A. Shanklin, S.C. Steinsberger,
and L. Cone, Entropy, Inc. Prepared for U.S. Environmental
Protection Agency, Research Triangle Park, NC. NTIS Report No. PB90-
221896. (1989).
3. ``Fourier Transform Infrared (FTIR) Method Validation at a
Coal Fired-Boiler,'' Entropy, Inc. Prepared for U.S. Environmental
Protection Agency, Research Triangle Park, NC. EPA Publication No.
EPA-454/R95-004. NTIS Report No. PB95-193199. (1993).
4. ``Field Validation Test Using Fourier Transform Infrared
(FTIR) Spectrometry To Measure Formaldehyde, Phenol and Methanol at
a Wool Fiberglass Production Facility.'' Draft. U.S. Environmental
Protection Agency Report, Entropy, Inc., EPA Contract No. 68D20163,
Work Assignment I-32.
5. Kinner, L.L., Geyer, T.G., Plummer, G.W., Dunder, T.A.,
Entropy, Inc. ``Application of FTIR as a Continuous Emission
Monitoring System.'' Presentation at 1994 International Incineration
Conference, Houston, Tx. May 10, 1994.
6. ``Molecular Vibrations; The Theory of Infrared and Raman
Vibrational Spectra,'' E. Bright Wilson, J.C. Decius, and P.C.
Cross, Dover Publications, Inc., 1980. For a less intensive
treatment of molecular rotational-vibrational spectra see, for
example, ``Physical Chemistry,'' G.M. Barrow, chapters 12, 13, and
14, McGraw Hill, Inc., 1979.
7. ``Laboratory and Field Evaluations of Ammonium Chloride
Interference in Method 26,'' U.S. Environmental Protection Agency
Report, Entropy, Inc., EPA Contract No. 68D20163, Work Assignment
No. I-45.
8. 40 CFR 63, A. Method 301--Field Validation of Pollutant
Measurement Methods from Various Waste Media.
9. ``Fourier Transform Infrared Spectrometry,'' Peter R.
Griffiths and James de Haseth, Chemical Analysis, 83, 16-25,(1986),
P.J. Elving, J.D. Winefordner and I.M. Kolthoff (ed.), John Wiley
and Sons.
10. ``Computer-Assisted Quantitative Infrared Spectroscopy,''
Gregory L. McClure (ed.), ASTM Special Publication 934 (ASTM), 1987.
11. ``Multivariate Least-Squares Methods Applied to the
Quantitative Spectral Analysis of Multicomponent Mixtures,'' Applied
Spectroscopy, 39(10), 73-84, 1985.
BILLING CODE 6560-50-P
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Method 322--Measurement of Hydrogen Chloride Emissions From Portland
Cement Kilns by GFCIR
1.0 Applicability and Principle
1.1 Applicability. This method is applicable to the
determination of hydrogen chloride (HCl) concentrations in emissions
from portland cement kilns. This is an instrumental method for the
measurement of HCl using an extractive sampling system and an
infrared (IR) gas-filter correlation (GFC) analyzer. This method is
intended to provide the cement industry with a direct interface
instrumental method. A procedure for analyte spiking is included for
quality assurance. This method is considered to be self-validating
provided that the requirements in section 9 of this method are
followed.
1.2 Principle. A gas sample is continuously extracted from a
stack or duct over the test period using either a source-level hot/
wet extractive subsystem or a dilution extractive subsystem. A
nondispersive infrared gas filter correlation (NDIR-GFC) analyzer is
specified for the measurement of HCl in the sample. The total
measurement system is comprised of the extractive subsystem, the
analyzer, and the data acquisition subsystem. Test system
performance specifications are included in this method to provide
for the collection of accurate, reproducible data.
1.3 Test System Operating Range. The measurement range (span)
of the test system shall include the anticipated HCl concentrations
of the effluent and spiked samples. The range should be selected so
that the average of the effluent measurements is between 25 and 75
percent of span. If at any time during a test run, the effluent
concentration exceeds the span value of the test system, the run
shall be considered invalid.
2.0 Summary of Method
2.1 Sampling and Analysis. Kiln gas is continuously extracted
from the stack or duct using either a source level, hot/wet
extractive system, or an in-situ dilution probe or heated out-of-
stack dilution system. The sample is then directed by a heated
sample line maintained above 350 deg.F to a GFC analyzer having a
range appropriate to the type of sampling system. The gas filter
correlation analyzer incorporates a gas cell filled with HCl. This
gas cell is periodically moved into the path of an infrared
measurement beam of the instrument to filter out essentially all of
the HCl absorption wavelengths. Spectral filtering provides a
reference from which the HCl concentration of the sample can be
determined. Interferences are minimized in the analyzer by choosing
a spectral band over which compounds such as CO2 and
H2O either do not absorb significantly or do not match
the spectral pattern of the HCl infrared absorption.
2.2 Operator Requirements. The analyst must be familiar with
the specifications and test procedures of this method and follow
them in order to obtain reproducible and accurate data.
3.0 Definitions
3.1 Measurement System. The total equipment required for the
determination of gas concentration. The measurement system consists
of the following major subsystems:
3.1.1 Sample Interface. That portion of a system used for one
or more of the following: sample acquisition, sample transport,
sample conditioning, or protection of the analyzers from the effects
of the stack gas.
3.1.2 Gas Analyzer. That portion of the system that senses the
gas to be measured and generates an output proportional to its
concentration.
3.1.3 Data Recorder. A strip chart recorder, analog computer,
or digital recorder for recording measurement data from the analyzer
output.
3.2 Span. The upper limit of the gas concentration measurement
range displayed on the data recorder.
3.3 Calibration Gas. A known concentration of a gas in an
appropriate diluent gas (i.e., N2).
3.4 Analyzer Calibration Error. The difference between the gas
concentration exhibited by the gas analyzer and the known
concentration of the calibration gas when the calibration gas is
introduced directly to the analyzer.
3.5 Sampling System Bias. The sampling system bias is the
difference between the gas concentrations exhibited by the
measurement system when a known concentration gas is introduced at
the outlet of the sampling probe and the known value of the
calibration gas.
3.6 Response Time. The amount of time required for the
measurement system to display 95 percent of a step change in gas
concentration on the data recorder.
3.7 Calibration Curve. A graph or other systematic method of
establishing the relationship between the analyzer response and the
actual gas concentration introduced to the analyzer.
3.8 Linearity. The linear response of the analyzer or test
system to known calibration inputs covering the concentration range
of the system.
3.9 Interference Rejection. The ability of the system to reject
the effect of interferences in the analytical measurement processes
of the test system.
4.0 Interferences
4.1 Sampling System Interferences. An important consideration
in measuring HCl using an extractive measurement system is to ensure
that a representative kiln gas sample is delivered to the gas
analyzer. A sampling system interferant is a factor that inhibits an
analyte from reaching the analytical instrumentation. Condensed
water vapor is a strong sampling system interferant for HCl and
other water soluble compounds. ``Cold spots'' in the sampling system
can allow water vapor in the sample to condense resulting in removal
of HCl from the sample stream. The extent of HCl sampling system
bias depends on concentrations of potential interferants, moisture
content of the gas stream, temperature of the gas stream,
temperature of sampling system components, sample flow rate, and
reactivity of HCl with other species in the gas stream. For
measuring HCl in a wet gas stream, the temperatures of the gas
stream and sampling system components and the sample flow rate are
of primary importance. In order to prevent problems with
condensation in the sampling system, these parameters must be
closely monitored.
4.1.1 System Calibration Checks. Performing these calibration
checks where HCl calibration gas is injected through the entire
system both before and after each test run demonstrates the
integrity of the sampling system and capability of the analyzer for
measuring this water soluble and otherwise unstable compound under
ideal conditions (i.e., HCl in N2).
4.1.2 Analyte Spiking Checks. For analyte spiking checks, HCl
calibration gas is quantitatively added to the sample stream at a
point upstream of the particulate filter and all other sample
handling components both before and after each test run. The volume
of HCl spike gas should not exceed 10 percent of the total sample
volume so that the sample matrix is relatively unaffected.
Successfully performing these checks demonstrates the integrity of
the sampling system for measuring this water soluble and reactive
compound under actual sample matrix conditions. Successfully
performing these checks also demonstrates the adequacy of the
interference rejection capability of the analyzer. (See section 9.3
of this method.)
4.2 Analytical Interferences. Analytical interferences are
reduced by the GFC spectroscopic technique required by the method.
The accuracy of HCl measurements provided by some GFC analyzers is
known to be sensitive to the moisture content of the sample. This
must be taken into account in order to acquire accurate results.
These analyzers must be calibrated for the specific moisture content
of the samples.
5.0 Safety
This method may involve sampling at locations having high
positive or negative pressures, or high concentrations of hazardous
or toxic pollutants, and cannot address all safety problems
encountered under these diverse sampling conditions. It is the
responsibility of the tester(s) to ensure proper safety and health
practices, and to determine the applicability of regulatory
limitations before performing this test method. Because HCl is a
respiratory irritant, it is advisable to limit exposure to this
compound.
6.0 Equipment and Supplies.
(Note: Mention of company or product names does not constitute
endorsement by the U. S. Environmental Protection Agency.)
6.1 Measurement System. Use any GFC measurement system for HCl
that meets the specifications of this method. All sampling system
components must be maintained above the kiln gas temperature, when
possible, or at least 350 deg.F. The length of sample transport
line should be minimized and sampling rate should be as high as
possible to minimize adsorption of HCl. The essential components of
the measurement system are described in sections 6.1.1 through
6.1.12.
6.1.1 Sample Probe. Glass, stainless steel, Hastalloy
TM, or equivalent, of sufficient
[[Page 14245]]
length to traverse the sample points. The sampling probe shall be
heated to a minimum of 350 deg.F to prevent condensation. Dilution
extractive systems must use a dilution ratio such that the average
diluted concentrations are between 25 to 75 percent of the selected
measurement range of the analyzer.
6.1.2 Calibration Valve Assembly. Use a heated, three-way valve
assembly, or equivalent, for selecting either sample gas or
introducing calibration gases to the measurement system or
introducing analyte spikes into the measurement system at the outlet
of the sampling probe before the primary particulate filter.
6.1.3 Particulate Filter. A coarse filter or other device may
be placed at the inlet of the probe for removal of large particulate
(10 microns or greater). A heated (Balston or
equivalent) filter rated at 1 micron is necessary for primary
particulate removal, and shall be placed immediately after the
heated probe. The filter/filter holder shall be maintained at 350
deg.F or a higher temperature. Additional filters at the inlet of
the gas analyzer may be used to prevent accumulation of particulate
material in the measurement system and extend the useful life of
components. All filters shall be fabricated of materials that are
nonreactive with HCl. Some types of glass filters are known to react
with HCl.
6.1.4 Sample Transport Lines. Stainless steel or
polytetrafluoroethylene (PTFE) tubing shall be heated to a minimum
temperature of 350 deg.F (sufficient to prevent condensation and to
prevent HCl and NH3 from combining into ammonium chloride
in the sampling system) to transport the sample gas to the gas
analyzer.
6.1.5 Sample Pump. Use a leak-free pump to pull the sample gas
through the system at a flow rate sufficient to minimize the
response time of the measurement system. The pump components that
contact the sample must be heated to a temperature greater than 350
deg.F and must be constructed of a material that is nonreactive to
HCl.
6.1.6 Sample Flow Rate Control. A sample flow rate control
valve and rotameter, or equivalent, must be used to maintain a
constant sampling rate within 10 percent. These
components must be heated to a temperature greater than 350 deg.F.
(Note: The tester may elect to install a back-pressure regulator to
maintain the sample gas manifold at a constant pressure in order to
protect the analyzer(s) from over-pressurization, and to minimize
the need for flow rate adjustments.)
6.1.7 Sample Gas Manifold. A sample gas manifold, heated to a
minimum of 350 deg.F, is used to divert a portion of the sample gas
stream to the analyzer and the remainder to the by-pass discharge
vent. The sample gas manifold should also include provisions for
introducing calibration gases directly to the analyzer. The manifold
must be constructed of material that is nonreactive to the gas being
sampled.
6.1.8 Gas Analyzer. Use a nondispersive infrared analyzer
utilizing the gas filter correlation technique to determine HCl
concentrations. The analyzer shall meet the applicable performance
specifications of section 8.0 of this method. (Note: Housing the
analyzer in a clean, thermally-stable, vibration free environment
will minimize drift in the analyzer calibration.) The analyzer
(system) shall be designed so that the response of a known
calibration input shall not deviate by more than 3
percent from the expected value. The analyzer or measurement system
manufacturer may provide documentation that the instrument meets
this design requirement. Alternatively, a known concentration gas
standard and calibration dilution system meeting the requirements of
Method 205 of appendix M to part 51 of this chapter, ``Verification
of Gas Dilution Systems for Field Calibrations'' (or equivalent
procedure), may be used to develop a multi-point calibration curve
over the measurement range of the analyzer.
6.1.9 Gas Regulators. Single stage regulator with cross purge
assembly that is used to purge the CGA fitting and regulator before
and after use. (This purge is necessary to clear the calibration gas
delivery system of ambient water vapor after the initial connection
is made, or after cylinder changeover, and will extend the life of
the regulator.) Wetted parts are 316 stainless steel to handle
corrosive gases.
6.1.10 Data Recorder. A strip chart recorder, analog computer,
or digital recorder, for recording measurement data. The data
recorder resolution (i.e., readability) shall be 0.5 percent of
span. Alternatively, a digital or analog meter having a resolution
of 0.5 percent of span may be used to obtain the analyzer responses
and the readings may be recorded manually. If this alternative is
used, the readings shall be obtained at equally-spaced intervals
over the duration of the sampling run. For sampling run durations of
less than 1 hour, measurements at 1-minute intervals or a minimum of
30 measurements, whichever is less restrictive, shall be obtained.
For sampling run durations greater than 1 hour, measurements at 2-
minute intervals or a minimum of 96 measurements, whichever is less
restrictive, shall be obtained.
6.1.11 Mass Flow Meters/Controllers. A mass flow meter having
the appropriate calibrated range and a stated accuracy of
2 percent of the measurement range is used to measure
the HCl spike flow rate. This device must be calibrated with the
major component of the calibration spike gas (e.g., nitrogen) using
an NIST traceable bubble meter or equivalent. When spiking HCl, the
mass flow meter/controller should be thoroughly purged before and
after introduction of the gas to prevent corrosion of the interior
parts.
6.1.12 System Flow Measurement. A measurement device or
procedure to determine the total flow rate of sample gas within the
measurement system. A rotameter, or mass flow meter calibrated
relative to a laboratory standard to within 2 percent of
the measurement value at the actual operating temperature, moisture
content, and sample composition (molecular weight) is acceptable. A
system which ensures that the total sample flow rate is constant
within 2 percent and which relies on an intermittent
measurement of the actual flow rate (e.g., calibrated gas meter) is
also acceptable.
6.2 HCl Calibration Gases. The calibration gases for the gas
analyzer shall be HCl in N2. Use at least three
calibration gases as specified below:
6.2.1 High-Range Gas. Concentration equivalent to 80 to 100
percent of the span.
6.2.2 Mid-Range Gas. Concentration equivalent to 40 to 60
percent of the span.
6.2.3 Zero Gas. Concentration of less than 0.25 percent of the
span. Purified ambient air may be used for the zero gas by passing
air through a charcoal filter or through one or more impingers
containing a solution of 3 percent H2O2.
6.2.4 Spike Gas. A calibration gas of known concentration
(typically 100 to 200 ppm) used for analyte spikes in accordance
with the requirements of section 9.3 of this method.
7.0 Reagents and Standards
7.1 Hydrogen Chloride. Hydrogen Chloride is a reactive gas and
is available in steel cylinders from various commercial gas vendors.
The stability is such that it is not possible to purchase a cylinder
mixture whose HCl concentration can be certified at better than
5 percent. The stability of the cylinder may be
monitored over time by periodically analyzing cylinder samples. The
cylinder gas concentration must be verified within 1 month prior to
the use of the calibration gas. Due to the relatively high
uncertainty of HCl calibration gas values, difficulties may develop
in meeting the performance specifications if the mid-range and high-
range calibration gases are not consistent with each other. Where
problems are encountered, the consistency of the test gas standards
may be determined: (1) By comparing analyzer responses for the test
gases with the responses to additional certified calibration gas
standards, (2) by reanalysis of the calibration gases in accordance
with sections 7.2.1 or 7.2.2 of this method, or (3) by other
procedures subject to the approval of EPA.
7.2 Calibration Gas Concentration Verification. There are two
alternatives for establishing the concentrations of calibration
gases. Alternative No. 1 is preferred.
7.2.1 Alternative No. 1. The value of the calibration gases may
be obtained from the vendor's certified analysis within 1 month
prior to the test. Obtain a certification from the gas manufacturer
that identifies the analytical procedures and date of certification.
7.2.2 Alternative No. 2. Perform triplicate analyses of the
gases using Method 26 of A to part 60 of this chapter. Obtain gas
mixtures with a manufacturer's tolerance not to exceed 5
percent of the tag value. Within 1 month of the field test, analyze
each of the calibration gases in triplicate using Method 26 of
appendix A to part 60 of this chapter. The tester must follow all of
the procedures in Method 26 (e.g., use midget impingers, heated
Pallflex TX40H175 filter (TFE-glass mat), etc. if this analysis is
performed. Citation 3 in section 13 of this method describes
procedures and techniques that may be used for this analysis. Record
the results on a data sheet. Each of the individual HCl analytical
results for each calibration gas shall be within 5 percent (or 5
ppm, whichever is greater) of the triplicate set average; otherwise,
discard the entire set and
[[Page 14246]]
repeat the triplicate analyses. If the average of the triplicate
analyses is within 5 percent of the calibration gas manufacturer's
cylinder tag value, use the tag value; otherwise, conduct at least
three additional analyses until the results of six consecutive runs
agree within 5 percent (or 5 ppm, whichever is greater) of the
average. Then use this average for the cylinder value.
7.3 Calibration Gas Dilution Systems. Sample flow rates of
approximately 15 L/min are typical for extractive HCl measurement
systems. These flow rates coupled with response times of 15 to 30
minutes will result in consumption of large quantities of
calibration gases. The number of cylinders and amount of calibration
gas can be reduced by the use of a calibration gas dilution system
in accordance with Method 205 of appendix M to part 51 of this
chapter, ``Verification of Gas Dilution Systems for Field Instrument
Calibrations.'' If this option is used, the tester shall also
introduce an undiluted calibration gas approximating the effluent
HCl concentration during the initial calibration error test of the
measurement system as a quality assurance check.
8.0 Test System Performance Specifications
8.1 Analyzer Calibration Error. This error shall be less than
5 percent of the emission standard concentration or
1 ppm, (whichever is greater) for zero, mid-, and high-
range gases.
8.2 Sampling System Bias. This bias shall be less than
7.5 percent of the emission standard concentration or
1.5 ppm (whichever is greater) for zero and mid-range
gases.
8.3 Analyte Spike Recovery. This recovery shall be between 70
to 130 percent of the expected concentration of spiked samples
calculated with the average of the before and after run spikes.
9.0 Sample Collection, Preservation, and Storage
9.1 Pretest. Perform the procedures of sections 9.1.1 through
9.1.3.3 of this method before measurement of emissions (procedures
in section 9.2 of this method). It is important to note that after a
regulator is placed on an HCl gas cylinder valve, the regulator
should be purged with dry N2 or dry compressed air for approximately
10 minutes before initiating any HCl gas flow through the system.
This purge is necessary to remove any ambient water vapor from
within the regulator and calibration gas transport lines; the HCl in
the calibration gas may react with this water vapor and increase
system response time. A purge of the system should also be performed
at the conclusion of a test day prior to removing the regulator from
the gas cylinder. Although the regulator wetted parts are corrosion
resistant, this will reduce the possibility of corrosion developing
within the regulator and extend the life of the equipment.
9.1.1 Measurement System Preparation. Assemble the measurement
system by following the manufacturer's written instructions for
preparing and preconditioning the gas analyzer and, as applicable,
the other system components. Introduce the calibration gases in any
sequence, and make all necessary adjustments to calibrate the
analyzer and the data recorder. If necessary, adjust the instrument
for the specific moisture content of the samples. Adjust system
components to achieve correct sampling rates.
9.1.2 Analyzer Calibration Error. Conduct the analyzer
calibration error check in the field by introducing calibration
gases to the measurement system at any point upstream of the gas
analyzer in accordance with sections 9.1.2.1 and 9.1.2.2 of this
method.
9.1.2.1 After the measurement system has been prepared for use,
introduce the zero, mid-range, and high-range gases to the analyzer.
During this check, make no adjustments to the system except those
necessary to achieve the correct calibration gas flow rate at the
analyzer. Record the analyzer responses to each calibration gas.
(Note: A calibration curve established prior to the analyzer
calibration error check may be used to convert the analyzer response
to the equivalent gas concentration introduced to the analyzer.
However, the same correction procedure shall be used for all
effluent and calibration measurements obtained during the test.
9.1.2.2 The analyzer calibration error check shall be considered
invalid if the difference in gas concentration displayed by the
analyzer and the concentration of the calibration gas exceeds
5 percent of the emission standard concentration or
1 ppm, (whichever is greater) for the zero, mid-, or
high-range calibration gases. If an invalid calibration is
exhibited, cross-check or recertify the calibration gases, take
corrective action, and repeat the analyzer calibration error check
until acceptable performance is achieved.
9.1.3 Sampling System Bias Check. For nondilution extractive
systems, perform the sampling system bias check by introducing
calibration gases either at the probe inlet or at a calibration
valve installed at the outlet of the sampling probe. For dilution
systems, calibration gases for both the analyzer calibration error
check and the sampling system bias check must be introduced prior to
the point of sample dilution. For dilution and nondilution systems,
a zero gas and either a mid-range or high-range gas (whichever more
closely approximates the effluent concentration) shall be used for
the sampling system bias check.
9.1.3.1 Introduce the upscale calibration gas, and record the
gas concentration displayed by the analyzer. Then introduce zero
gas, and record the gas concentration displayed by the analyzer.
During the sampling system bias check, operate the system at the
normal sampling rate, and make no adjustments to the measurement
system other than those necessary to achieve proper calibration gas
flow rates at the analyzer. Alternately introduce the zero and
upscale gases until a stable response is achieved. The tester shall
determine the measurement system response time by observing the
times required to achieve a stable response for both the zero and
upscale gases. Note the longer of the two times and note the time
required for the measurement system to reach 95 percent of the step
change in the effluent concentration as the response time.
9.1.3.2 For nondilution systems, where the analyzer calibration
error test is performed by introducing gases directly to the
analyzer, the sampling system bias check shall be considered invalid
if the difference between the gas concentrations displayed by the
measurement system for the sampling system bias check and the known
gas concentration standard exceeds 7.5 percent of the
emission standard or 1.5 ppm, (whichever is greater) for
either the zero or the upscale calibration gases. If an invalid
calibration is exhibited, take corrective action, and repeat the
sampling system bias check until acceptable performance is achieved.
If adjustment to the analyzer is required, first repeat the analyzer
calibration error check, then repeat the sampling system bias check.
9.1.3.3 For dilution systems (and nondilution systems where all
calibration gases are introduced at the probe), the comparison of
the analyzer calibration error results and sampling system bias
check results is not meaningful. For these systems, the sampling
system bias check shall be considered invalid if the difference
between the gas concentrations displayed by the analyzer and the
actual gas concentrations exceed 7.5 percent of the
emission standard or 1.5 ppm, (whichever is greater) for
either the zero or the upscale calibration gases. If an invalid
calibration is exhibited, take corrective action, and repeat the
sampling system bias check until acceptable performance is achieved.
If adjustment to the analyzer is required, first repeat the analyzer
calibration error check.
9.2 Emission Test Procedures
9.2.1 Selection of Sampling Site and Sampling Points. Select a
measurement site and sampling points using the same criteria that
are applicable to Method 26 of A to part 60 of this chapter.
9.2.2 Sample Collection. Position the sampling probe at the
first measurement point, and begin sampling at the same rate as used
during the sampling system bias check. Maintain constant rate
sampling (i.e., 10 percent) during the entire run. Field
test experience has shown that conditioning of the sample system is
necessary for approximately 1-hour prior to conducting the first
sample run. This conditioning period should be repeated after
particulate filters are replaced and at the beginning of each new
day or following any period when the sampling system is inoperative.
Experience has also shown that prior to adequate conditioning of the
system, the response to analyte spikes and/or the change from an
upscale calibration gas to a representative effluent measurement may
be delayed by more than twice the normal measurement system response
time. It is recommended that the analyte spikes (see section 9.3 of
this method) be performed to determine if the system is adequately
conditioned. The sampling system is ready for use when the time
required for the measurement system to equilibrate after a change
from a representative effluent measurement to a representative
spiked sample measurement approximates the calibration gas response
time observed in section 9.1.3.1 of this method.
[[Page 14247]]
9.2.3 Sample Duration. After completing the sampling system
bias checks and analyte spikes prior to a test run, constant rate
sampling of the effluent should begin. For each run, use only those
measurements obtained after all residual response to calibration
standards or spikes are eliminated and representative effluent
measurements are displayed to determine the average effluent
concentration. At a minimum, this requires that the response time of
the measurement system has elapsed before data are recorded for
calculation of the average effluent concentration. Sampling should
be continuous for the duration of the test run. The length of data
collection should be at least as long as required for sample
collection by Method 26 of part 60 of this chapter. One hour
sampling runs using this method have provided reliable data for
cement kilns.
9.2.4 Validation of Runs. Before and after each run, or if
adjustments are necessary for the measurement system during the run,
repeat the sampling system bias check procedure described in section
9.1.3 of this method. (Make no adjustments to the measurement system
until after the drift checks are completed.) Record the analyzer's
responses.
9.2.4.1 If the post-run sampling system bias for either the
zero or upscale calibration gas exceeds the sampling system bias
specification, then the run is considered invalid. Take corrective
action, and repeat both the analyzer calibration error check
procedure (section 9.1.2 of this method) and the sampling system
bias check procedure (section 9.1.3 of this method) before repeating
the run.
9.2.4.2 If the post-run sampling system bias for both the zero
and upscale calibration gas are within the sampling system bias
specification, then construct two 2-point straight lines, one using
the pre-run zero and upscale check values and the other using the
post-run zero and upscale check values. Use the slopes and y-
intercepts of the two lines to calculate the gas concentration for
the run in accordance with equation 1 of this method.
9.3 Analyte Spiking--Self-Validating Procedure. Use analyte
spiking to verify the effectiveness of the sampling system for the
target compounds in the actual kiln gas matrix. Quality assurance
(QA) spiking should be performed before and after each sample run.
The spikes may be performed following the sampling system bias
checks (zero and mid-range system calibrations) before each run in a
series and also after the last run. The HCl spike recovery should be
within 30 percent as calculated using equations 1 and 2
of this method. Two general approaches are applicable for the use of
analyte spiking to validate a GFC HCl measurement system: (1) Two
independent measurement systems can be operated concurrently with
analyte spikes introduced to one of the systems, or (2) a single
measurement system can be used to analyze consecutively, spiked and
unspiked samples in an alternating fashion. The two-system approach
is similar to Method 301 of this appendix and the measurement bias
is determined from the difference in the paired concurrent
measurements relative to the amount of HCl spike added to the spiked
system. The two-system approach must employ identical sampling
systems and analyzers and both measurement systems should be
calibrated using the same mid- and high-range calibration standards.
The two-system approach should be largely unaffected by temporal
variations in the effluent concentrations if both measurement
systems achieve the same calibration responses and both systems have
the same response times. (See Method 301 of this appendix for
appropriate calculation procedures.) The single measurement system
approach is applicable when the concentration of HCl in the source
does not vary substantially during the period of the test. Since the
approach depends on the comparison of consecutive spiked and
unspiked samples, temporal variations in the effluent HCl
concentrations will introduce errors in determining the expected
concentration of the spiked samples. If the effluent HCl
concentrations vary by more than 10 percent (or
5 ppm, whichever is greater) during the time required to
obtain and equilibrate a new sample (system response time), it may
be necessary to: (1) Use a dual sampling system approach, (2)
postpone testing until stable emission concentrations are achieved,
(3) switch to the two-system approach [if possible] or, (4) rely on
alternative QA/QC procedures. The dual-sampling system alternative
uses two sampling lines to convey sample to the gas distribution
manifold. One of the sample lines is used to continuously extract
unspiked kiln gas from the source. The other sample line serves as
the analyte spike line. One GFC analyzer can be used to alternately
measure the HCl concentration from the two sampling systems with the
need to purge only the components between the common manifold and
the analyzer. This minimizes the time required to acquire an
equilibrated sample of spiked or unspiked kiln gas. If the source
varies by more than #10 percent or 5 ppm,
(whichever is greater) during the time it takes to switch from the
unspiked sample line to the spiked sample line, then the dual-
sampling system alternative approach is not applicable. As a last
option, (where no other alternatives can be used) a humidified
nitrogen stream may be generated in the field which approximates the
moisture content of the kiln gas. Analyte spiking into this
humidified stream can be employed to assure that the sampling system
is adequate for transporting the HCl to the GFC analyzer and that
the analyzer's water interference rejection is adequate.
9.3.1 Spike Gas Concentration and Spike Ratio. The volume of
HCl spike gas should not exceed 10 percent of the total sample
volume (i.e., spike to total sample ratio of 1:10) to ensure that
the sample matrix is relatively unaffected. An ideal spike
concentration should approximate the native effluent concentration,
thus the spiked sample concentrations would represent approximately
twice the native effluent concentrations. The ideal spike
concentration may not be achieved because the native HCl
concentration cannot be accurately predicted prior to the field
test, and limited calibration gas standards will be available during
the field test. Some flexibility is available by varying the spike
ratio over the range from 1:10 to 1:20. Practical constraints must
be applied to allow the tester to spike at an anticipated
concentration. Thus, the tester may use a 100 ppm calibration gas
and a spike ratio of 1:10 as default values where information
regarding the expected HCl effluent concentration is not available
prior to the tests. Alternatively, the tester may select another
calibration gas standard and/or lower spike ratio (e.g., 1:20) to
more closely approximate the effluent HCl concentration.
9.3.2 Spike Procedure. Introduce the HCl spike gas mixture at a
constant flow rate (2 percent) at less than 10 percent
of the total sample flow rate. (For example, introduce the HCl spike
gas at 1 L/min (20 cc/min) into a total sample flow rate
of 10 L/min). The spike gas must be preheated before introduction
into the sample matrix to prevent a localized condensation of the
gas stream at the spike introduction point. A heated sample
transport line(s) containing multiple transport tubes within the
heated bundle may be used to spike gas up through the sampling
system to the spike introduction point. Use a calibrated flow device
(e.g., mass flow meter/controller) to monitor the spike flow rate.
Use a calibrated flow device (e.g., rotameter, mass flow meter,
orifice meter, or other method) to monitor the total sample flow
rate. Calculate the spike ratio from the measurements of spike flow
and total flow. (See equation 2 and 3 in section 10.2 of this
method.)
9.3.3 Analyte Spiking. Determine the approximate effluent HCl
concentrations by examination of preliminary samples. For single-
system approaches, determine whether the HCl concentration varies
significantly with time by comparing consecutive samples for the
period of time corresponding to at least twice the system response
time. (For analyzers without sample averaging, estimate average
values for two to five minute periods by observing the instrument
display or data recorder output.) If the concentration of the
individual samples varies by more than 10 percent
relative to the mean value or 5 ppm, (whichever is
greater), an alternate approach may be needed.
9.3.3.1 Adjust the spike flow rate to the appropriate level
relative to the total flow by metering spike gas through a
calibrated mass flow meter or controller. Allow spike flow to
equilibrate within the sampling system for at least the measurement
system response time and a steady response to the spike gas is
observed before recording response to the spiked gas sample. Next,
terminate the spike gas flow and allow the measurement system to
sample only the effluent. After the measurement system response time
has elapsed and representative effluent measurements are obtained,
record the effluent unspiked concentration. Immediately calculate
the spike recovery.
9.3.3.2 If the spike recovery is not within acceptable limits
and a change in the effluent concentration is suspected as the cause
for exceeding the recovery limit, repeat the analyte spike procedure
without making any adjustments to the analyzer or sampling system.
If the second spike recovery falls within the recovery limits,
disregard the first
[[Page 14248]]
attempt and record the results of the second spike.
9.3.3.3 Analyte spikes must be performed before and after each
test run. Sampling system bias checks must also be performed before
and after each test run. Depending on the particular sampling
strategy and other constraints, it may be necessary to compare
effluent data either immediately before or immediately after the
spike sample to determine the spike recovery. Either method is
acceptable provided a consistent approach is used for the test
program. The average spike recovery for the pre-and post-run spikes
shall be used to determine if spike recovery is between 70 and 130
percent.
10.0 Data Analysis and Emission Calculations
The average gas effluent concentration is determined from the
average gas concentration displayed by the gas analyzer and is
adjusted for the zero and upscale sampling system bias checks, as
determined in accordance with section 9.2.3 of this method. The
average gas concentration displayed by the analyzer may be
determined by integration of the area under the curve for chart
recorders, or by averaging all of the effluent measurements.
Alternatively, the average may be calculated from measurements
recorded at equally spaced intervals over the entire duration of the
run. For sampling run durations of less than 1-hour, average
measurements at 2-minute intervals or less, shall be used. For
sampling run durations greater than 1-hour, measurements at 2-minute
intervals or a minimum of 96 measurements, whichever is less
restrictive, shall be used. Calculate the effluent gas concentration
using equation 1.
[GRAPHIC] [TIFF OMITTED] TP24MR98.025
Where:
bc=Y-intercept of the calibration least-squares line.
bf=Y-intercept of the final bias check 2-point line.
bi=Y-intercept of the initial bias check 2-point line.
Cgas=Effluent gas concentration, as measured, ppm.
Cavg=Average gas concentration indicated by gas analyzer,
as measured, ppm.
mc=Slope of the calibration least-squares line.
mf=Slope of the final bias check 2-point line.
mi=Slope of the initial bias check 2-point line.
The following equations are used to determine the percent
recovery (%R) for analyte spiking:
%R=(SM/CE) x 100 (Eq. 322-2)
Where:
SM=Mean concentration of duplicate analyte spiked samples
(observed).
CE=Expected concentration of analyte spiked samples
(theoretical).
CE=CS(QS/
QT)+SU(1-QS/QT) (Eq.
322-3)
Where:
CS=Concentration of HCl spike gas (cylinder tag value).
QS=Spike gas flow rate.
QT=Total sample flow rate (effluent sample flow plus
spike flow).
SU=Native concentration of HCl in unspiked effluent
samples.
Acceptable recoveries for analyte spiking are 30
percent.
11.0 Pollution Prevention
Gas extracted from the source and analyzed or vented from the
system manifold shall be either scrubbed, exhausted back into the
stack, or discharged into the atmosphere where suitable dilution can
occur to prevent harm to personnel health and welfare or plant or
personal property.
12.0 Waste Management
Gas standards of HCl are handled as according to the
instructions enclosed with the materials safety data sheets.
13.0 References
1. Peeler, J.W., Summary Letter Report to Ann Dougherty,
Portland Cement Association, June 20, 1996.
2. Test Protocol, Determination of Hydrogen Chloride Emissions
from Cement Kilns (Instrumental Analyzer Procedure) Revision 4; June
20, 1996.
3. Westlin, Peter R. and John W. Brown. Methods for Collecting
and Analyzing Gas Cylinder Samples. Source Evaluation Society
Newsletter. 3(3):5-15. September 1978.
[FR Doc. 98-6678 Filed 3-23-98; 8:45 am]
BILLING CODE 6560-50-P
