[Federal Register Volume 63, Number 75 (Monday, April 20, 1998)]
[Proposed Rules]
[Pages 19582-19612]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 98-10142]
[[Page 19581]]
_______________________________________________________________________
Part II
Environmental Protection Agency
_______________________________________________________________________
40 CFR Part 63
National Emission Standards for Hazardous Air Pollutants for Source
Categories: National Emission Standards for Primary Copper Smelters;
Proposed Rule
Federal Register / Vol. 63, No. 75 / Monday, April 20, 1998 /
Proposed Rules
[[Page 19582]]
ENVIRONMENTAL PROTECTION AGENCY
40 CFR Part 63
[IL-64-2-5807; FRL-5997-7]
RIN 2060-AE41
National Emission Standards for Hazardous Air Pollutants for
Source Categories: National Emission Standards for Primary Copper
Smelters
AGENCY: Environmental Protection Agency (EPA).
ACTION: Proposed rule and notice of public hearing.
-----------------------------------------------------------------------
SUMMARY: This action proposes national emission standards for hazardous
air pollutants (NESHAP) for new and existing primary copper smelters
under section 112 of the Clean Air Act (Act), as amended in November
1990. Primary copper smelters can potentially emit significant amounts
of certain toxic metals that have been identified in the Act as
hazardous air pollutants (HAP). Overall, the HAP emitted in the largest
quantities from primary copper smelters are arsenic compounds and lead
compounds. Chronic exposure to arsenic is associated with human cancers
of the skin, bladder, liver and lungs and can cause other developmental
and reproductive effects. Exposure to lead compounds results in adverse
effects on the blood, central nervous system, and kidneys. The proposed
NESHAP would require use of air emission controls to reduce HAP
emissions from primary copper smelters that produce anode copper using
flash smelting furnaces integrated with batch copper converters. The
EPA estimates that the proposed NESHAP would reduce annual nationwide
HAP emissions from the source category by approximately 20 percent or
34 megagrams per year (37.5 tons per year). The NESHAP provides
protection to the public by requiring the affected primary copper
smelters to meet emission standards that reflect the application of
maximum achievable control technology (MACT).
DATES: Comments. The EPA will accept comments regarding this proposed
NESHAP on or before June 19, 1998.
Public Hearing. If anyone contacts the EPA requesting to speak at a
public hearing May 11, 1998 a public hearing will be held May 20, 1998
beginning at 10:00 a.m. For more information, see section IX.B of
SUPPLEMENTARY INFORMATION.
ADDRESSES: Comments: Written comments (in duplicate, if possible)
should be submitted to Docket No. A-96-22 at the following address:
U.S. Environmental Protection Agency, Air and Radiation Docket and
Information Center (6102), 401 M Street, SW., Washington, DC 20460. The
EPA requests that a separate copy of the comments also be sent to the
contact person listed below. The docket is located at the above address
in Room M-1500, Waterside Mall (ground floor).
A copy of today's notice and other materials related to this
rulemaking are available for review in the docket. Copies of this
information may be obtained by request from the Air Docket by calling
(202) 260-7548. A reasonable fee may be charged for copying the docket
materials.
Public Hearing. If anyone contacts the EPA requesting a public
hearing by the required dates (see DATES), the public hearing will be
held at the EPA Office of Administration Auditorium, Research Triangle
Park, NC. Persons inquiring as to whether a hearing is to be held
should call the contact person listed below.
FOR FURTHER INFORMATION CONTACT: Mr. Eugene Crumpler, Metals Group,
Emission Standards Division (MD-13), U.S. Environmental Protection
Agency, Research Triangle Park, NC, 27711, telephone number (919) 541-
0881, facsimile number (919) 541-5600, electronic mail address
``[email protected].''.
SUPPLEMENTARY INFORMATION:
Regulated Entities
Entities potentially regulated by this action are primary copper
smelters (SIC 3339). No federal government entities nor State/local/
tribal government entities would be regulated by final action on this
proposal.
This description of the regulated entities is not intended to be
exhaustive, but rather provides a guide for readers regarding entities
likely to be regulated by final action on this proposal. This
description identifies the types of entities that the EPA is now aware
could potentially be regulated by final action on this proposal. To
determine whether your facility is regulated by final action on this
proposal, you should carefully examine the applicability criteria in
section V.A of this document, and in Sec. 63.1440 of the proposed rule.
If you have any questions regarding the applicability of this action to
a particular entity, consult the person listed in the preceding FOR
FURTHER INFORMATION CONTACT section.
Technology Transfer Network
The text of today's notice 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
also is accessible through the Internet at ``TELNET
ttnbbs.rtpnc.epa.gov.'' If more information on the TTN is needed, call
the HELP line at (919) 541-5348. The HELP desk is staffed Monday
through Friday from 11 a.m. to 5 p.m.; a voice menu system is available
at other times.
Electronic Access and Filing Addresses
The official record for this rulemaking, as well as the public
version, has been established under Docket No. A-96-22 (including
comments and data submitted electronically). A public version of this
record, including printed, paper versions of electronic comments, which
does not include any information claimed as confidential business
information (CBI), is available for inspection from 8 a.m. to 5:30 p.m.
Monday through Friday, excluding legal holidays. The official
rulemaking record is located at the address in ADDRESSES at the
beginning of this document.
Electronic comments can be sent directly to EPA's Air and Radiation
Docket and Information Center at: ``A-and-R-D[email protected].''
Electronic comments 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 in 5.1 file format or
ASCII file format. All comments and data in electronic form must be
identified by the docket number (A-96-22). No CBI should be submitted
through electronic mail. Electronic comments on this proposed rule may
be filed online at many Federal Depository Libraries.
Outline
The information in this notice is organized as follows.
I. Statutory Authority
II. Initial List of Categories of Major and Area Sources
III. Background
A. ``Primary Copper Smelting'' Source Category Description
B. HAP Emissions
1. Process HAP Emissions
2. Process Fugitive HAP Emissions
3. Fugitive Dust Emissions
4. Existing Air Emission Controls
C. Relationship to Other Air Rules
IV. NESHAP Decision Process
A. Source of Authority for NESHAP Development
B. Criteria for Development of NESHAP
[[Page 19583]]
C. Determining the MACT Floor
V. Summary of the Proposed Standards
A. Applicability
B. Sources To Be Regulated
C. Emission Limits and Requirements
1. Copper Concentrate Dryers
2. Smelting Furnaces
3. Slag Cleaning Vessels
4. Batch Copper Converters
5. Fugitive Dust Sources
6. Equivalent Standard for Combined Exhaust Gas Streams
D. Compliance and Maintenance Requirements
1. Compliance Dates
2. Operation and Maintenance Requirements
E. Performance Testing Requirements
1. Particulate Matter Emissions Performance Tests
2. Visible Emissions Performance Tests
F. Inspection and Monitoring Requirements
1. Capture System Inspections
2. Capture System Monitoring
3. Control Device Inspections and Monitoring
G. Notification, Recordkeeping, and Reporting Requirements
1. Notifications
2. Records
3. Reports
VI. Impacts of Proposed Rule
A. Health Impacts
B. Air Quality Impacts
C. Other Environmental and Energy Impacts
D. Economic Impacts
VII. Rationale for Selection of Proposed Standards
A. Selection of Pollutants
B. Selection of Affected Sources
C. Selection of Basis and Level for the Proposed Standards
1. Background
2. Selection of Standards for Copper Concentrate Dryers
3. Selection of Standards for Smelting Furnaces
4. Selection of Standards for Slag Cleaning Vessels
5. Selection of Standards for Batch Copper Converters
6. Selection of Standards for Fugitive Dust Sources
D. Selection of Compliance Requirements
1. Selection of Compliance Dates
2. Selection of Test Methods
3. Selection of Monitoring Requirements
E. Selection of Notification, Recordkeeping, and Reporting
Requirements
VIII. Public Participation
IX. Administrative Requirements
A. Docket
B. Public Hearing
C. ``Significant Regulatory Action'' Determination Under
Executive Order 12866
D. Enhancing the Intergovernmental Partnership Under Executive
Order 12875
E. Clean Air Act
F. Paperwork Reduction Act
G. Pollution Prevention Act
H. Regulatory Flexibility
I. Unfunded Mandates Reform Act
I. Statutory Authority
The statutory authority for this proposal is provided by sections
101, 112, 114, 116, and 301 of the Clean Air Act, as amended (42 U.S.C.
7401, 7412, 7414, 7416, and 7601).
II. Initial List of Categories of Major and Area Sources
Section 112 of the Clean Air Act (Act) directs the EPA to establish
national standards to control hazardous air pollutant (HAP) emissions
from major and area sources, as defined in the Act. Control of HAP
emissions is achieved by promulgating for specific source categories
emission standards (under sections 112(d) and 112(f)) or operational
and work practice standards (under section 112(h)).
The initial list of the source categories selected by the EPA for
regulation under section 112 of the Act was published on July 16, 1992
(57 FR 31576). The EPA published an updated list of source categories
(61 FR 28202, June 4, 1996) to reflect source category listing
revisions that the EPA has made since the initial list was published.
``Primary Copper Smelting'' is one of the approximately 170 categories
of sources listed.
The ``Primary Copper Smelting'' source category consists of
facilities that produce anode copper by first flash smelting of copper
ore concentrates to obtain molten copper matte and then directly
convert the molten matte to blister copper using a batch copper
converting process. Batch copper converting is characterized by the use
of Pierce-Smith or Hoboken design copper converters to produce blister
copper from molten copper matte in discrete batches using a sequence of
charging, blowing, skimming, and pouring steps.
The origin of the HAP emissions from the ``Primary Copper
Smelting'' source category is metallic compound impurities (e.g.,
compounds containing arsenic, lead, or other types of heavy metals)
that naturally occur in the copper ore deposits. The listing of the
``Primary Copper Smelting'' source category is based on the
Administrator's determination that existing and new individual
facilities comprising this source category may reasonably be
anticipated to emit these HAP in sufficient quantity to be designated a
major source as defined under the Act. Information subsequently
collected by the EPA as part of this rulemaking confirms that existing
and new facilities in the ``Primary Copper Smelting'' source category
do emit or have the potential to emit at levels greater than 10 tons
per year (tpy) of an individual HAP or more than 25 tpy of total HAP
and therefore are major sources. The primary source of these emissions
are process fugitive emissions from the batch copper converting
process. A detailed process description for the ``Primary Copper
Smelting'' source category and the associated HAP emissions is
presented in sections III.A and III.B to this preamble.
Since the listing of the ``Primary Copper Smelting'' source
category, a new smelter operated by Kennecott Copper, in Garfield,
Utah, has been constructed. This smelter employs a new continuous flash
converting technology that is considerably different from the
conventional batch converting process used at the smelters which form
the basis for the listing of the ``Primary Copper Smelting'' source
category. The design and operation of the continuous flash converting
process eliminates many of the potential air pollutant emission sources
associated with batch copper converting. As a result, the smelter does
not emit HAP at major source levels and is therefore an area source.
III. Background
A. ``Primary Copper Smelting'' Source Category Description
The ``Primary Copper Smelting'' source category is comprised of a
total of six existing facilities nationwide. Each of these facilities
produces anode copper from copper ore concentrates using flash smelting
integrated with batch copper converting. All of the primary copper
smelters are owned and operated by major corporations (two companies
each own and operate two smelters). Each smelter is located in
relatively close proximity to the copper mines supplying the copper ore
concentrate processed at the individual smelter. Three smelters are
located in southeastern Arizona. Two smelters are located in
southwestern New Mexico. One smelter is located in El Paso, Texas.
Copper ore deposits typically contain less than 1 percent copper.
Once the ore is extracted from the ground, the ore is beneficated at
the mine site to produce a processed form of copper ore with a higher
copper content. Concentration of the ore is accomplished by crushing,
grinding, and flotation purification to obtain a processed ore
concentrate (referred to hereafter as ``copper concentrate'') typically
having a concentration of 15 to 25 percent copper, 25 to 30 percent
sulfur, 25 percent iron, 10 to 15 percent water, and small amounts of
other metals. The type and quantity of these metals in the
[[Page 19584]]
copper concentrate vary depending on the source of the ore, and can
include arsenic, antimony, bismuth, cadmium, lead, selenium, magnesium,
aluminum, cobalt, tin, nickel, tellurium, silver, gold and palladium.
The copper concentrate is shipped to the primary copper smelter by
trucks, rail cars, and, in some cases, slurry pipelines.
All domestic primary copper smelters operate flash smelting
furnaces. Once the copper concentrate is received at the smelter, the
copper concentrate must be further processed before feeding it to the
flash smelting furnace. Each smelter operates a combination of crushers
and mills to obtain the proper size material for feeding to the
smelting furnace. The copper concentrate is mixed with fluxes
(materials that facilitate formation of slag containing iron oxides and
other impurities). At most existing smelters, the moisture content of
the copper concentrate is reduced by passing the copper concentrate
through either a fluidized-bed dryer or rotary dryer. One existing
smelter currently is able to feed its copper concentrate directly to
the smelting furnace without prior drying.
The prepared copper concentrate and finely ground fluxes are
injected together with oxygen and preheated air into the furnace which
is maintained at approximately 1,000 deg.C (1,830 deg.F). The furnace
uses the heat generated from the partial oxidation of the sulfide
content in the copper concentrate to provide most, if not all of the
energy required for the smelting process. Supplemental heat is
supplied, as needed, using oil-fired or gas-fired burners to maintain
the required smelting temperature. The resulting molten material
collects in a bath at the bottom of the furnace. This molten bath
separates into two layers. The lighter density material layer is called
``slag'' and contains iron silicates and other impurities. The heavier
density material layer is called ``copper matte'' and contains up to 65
percent copper in the form of copper sulfide. The off-gases exhausted
from the furnace contain concentrated sulfur dioxide (SO2).
These off-gases are treated in a contact sulfuric acid plant to remove
98 to 99 percent or more of the SO2 in the gases before
being vented to the smelter main stack.
The molten copper matte and slag are removed from the flash
smelting furnace through tapholes along the side of the furnace.
Separate tapholes are used to remove the copper matte and the slag. The
molten material released through a taphole empties into a heated trough
(called a ``launder''). The molten copper matte flows down the launders
into large ladles for transfer to the batch copper converters. The
molten slag from the furnace either is directly disposed by
transferring it in slag pots to an on-site slag pile or, at some
smelters, processed further before final disposal to increase the
copper yield.
At two of the existing smelters, molten slag from the flash furnace
can be transferred to a second furnace (referred to hereafter as a
``slag cleaning vessel''). In the slag cleaning vessel, the slag from
the flash furnace is treated with coke or iron sulfide. Residual copper
in the slag is converted to form a copper sulfide layer which is tapped
and transferred to the batch copper converters. The slag is tapped and
discarded. Off-gases from the slag cleaning vessel contain low
concentrations of SO2 and are typically vented to a separate
wet scrubber control device.
Converting is an oxidation process that removes most of the sulfur,
iron, and other impurities in the copper matte to produce blister
copper (a 96 to 99 percent pure copper). Batch copper converting is
performed using large refractory-lined cylindrical steel vessels
mounted on trunnions at either end. A large circular opening on the
vessel body (the ``converter mouth'') provides access for adding or
removing molten materials and also allows gaseous by-products to escape
from the converter. A drive mechanism is used to rotate the position of
the converter mouth for charging materials to the converter and pouring
molten materials from the converter.
Batch copper converting produces blister copper in an 8-to-12 hour
batch cycle using three to five converters aligned in a row inside the
converter building. Operation of the converters is staggered such that,
at any given time, not all of the converters are being used for blister
copper production, and those that are ``on-line'' are operating in
different stages of the copper converting cycle. The batch copper
converting cycle follows a sequence of steps involving charging of
molten matte to the converter, blowing oxygen through the molten bath,
skimming off slag, and finally pouring the blister copper at the end of
the cycle. Material is added to or removed from each converter using
large ladles which are positioned and transported using a traveling
overhead crane. Off-gases from each converter are vented during blowing
to a common ventilation system for routing to the sulfuric acid plant.
A converter batch cycle begins by charging an empty converter with
molten matte tapped from the flash smelting furnace. Air or oxygen-
enriched air is then blown into the molten matte through a series of
pipes (called ``tuyeres'') on the side of the converter. The iron
sulfide in the matte is preferentially oxidized to form iron oxides and
SO2. The SO2 is exhausted from the converter in
the off-gases vented to the sulfuric acid plant operated at the smelter
site. Flux is added to combine with the iron oxide and forms a top
layer of iron silicate slag on the molten bath in the converter. The
resulting slag layer is removed from the molten bath by discontinuing
blowing and then rotating the converter mouth down to skim off the
slag. The blowing and slag skimming steps are repeated until an
adequate amount of relatively pure copper sulfide (called ``white
metal'') accumulates in the converter. A final blow oxidizes the copper
sulfide to SO2, and blister copper forms. At this time, the
blister copper is poured from the converter for transfer to the copper
refining operations. The converter is then available to begin a new
batch cycle.
Two different batch copper converter designs are used in the United
States. Five smelters use the Pierce-Smith converter design. An
alternative to the Pierce-Smith converter is the Hoboken converter
design, which is used by one domestic smelter. The design and operation
of these two types of batch copper converters is similar with the
exception of the means by which off-gases vented from the converter are
captured for venting to the sulfuric acid plant.
The Pierce-Smith converter design uses a large external hood to
cover the converter mouth when the converter is rotated into position
for the blowing. The hood for each converter in the converter aisle is
connected to a common ventilation system that exhausts the captured
off-gases to the sulfuric acid plant.
In contrast, the Hoboken converter design does not use an external
hood for capture of the off-gases during blowing. The Hoboken converter
is fitted with a ``U''-shaped side flue located at one end of the
converter. The side flue allows siphoning of the converter off-gases
directly from the interior of the converter for venting to the sulfuric
acid plant. Off-gases are prevented from escaping through the uncovered
Hoboken converter mouth during blowing by operating the ventilation
system draft at a level such that a slight negative pressure is
maintained at the converter mouth.
At the end of the batch converting cycle, the blister copper is
poured from the converter for further processing by fire refining to
produce anode copper. Fire refining of blister copper is conducted in a
cylindrical vessel similar
[[Page 19585]]
to a batch copper converter. Flux is added and air is blown through the
molten blister copper mixture to oxidize the copper and any remaining
impurities. The impurities are removed as slag. The remaining copper
oxide is then subject to a reducing atmosphere to form a very high
purity copper. The fire-refined copper is then cast into anodes for
further electrolytic refining.
The anode copper is processed by an electrolytic process to obtain
commercial grade copper for sale as a product. Electrolytic refining
separates copper from the remaining impurities by electrolysis in a
solution containing copper sulfate and sulfuric acid. The copper anode
is dissolved and the elemental copper is re-deposited at the cathode.
As the copper anode dissolves, residual metallic impurities in the
anode copper precipitate in the acid solution and form a sludge. The
resulting cathode copper is now more than 99.9 percent pure and is cast
into bars, ingots, or slabs for sale.
B. HAP Emissions
Under section 112(b) of the Act, Congress listed specific
chemicals, compounds, or groups of chemicals that are HAP's subject to
control under a NESHAP. Metals beside copper naturally occur in copper
ore deposits. These metallic ``impurities'' include metals that are
listed as HAP. Lead and arsenic are found in the largest quantities in
copper ore mined and smelted in the United States. Lesser quantities of
antimony, beryllium, cadmium, chromium, cobalt, manganese, nickel, and
selenium also are frequently present in U.S. copper ore. These metallic
impurities in the copper ore can be released into the atmosphere in the
form of particulate matter (PM) during certain smelting operations, and
are the source of the HAP emissions from primary copper smelters. The
composition and quantity of the potential HAP emissions from a given
smelter is directly related to the level of metal impurities in the
copper concentrate processed at the smelter. The organic chemicals and
acid gases that are listed as HAP have no or minimal potential to be
emitted to the atmosphere from domestic primary copper smelters.
On an industry-wide basis, the composition of the HAP emissions
from primary copper smelters is approximately 50 percent lead
compounds, 25 percent arsenic compounds, and lesser amounts of the
other metals. The composition and quantity of the potential HAP
emissions from a given smelter is directly related to the level of
metal impurities in the copper concentrate processed at the smelter.
The sources of HAP emitted from smelters using flash smelting furnaces
integrated with batch copper converters can be characterized as: (1)
process HAP emissions; (2) process fugitive HAP emissions; and (3)
fugitive dust emissions. Electrolytic refining of anode copper does not
produce any metallic HAP emissions.
1. Process HAP Emissions
Process HAP emissions are the HAP contained in the primary exhaust
gas stream (i.e., off-gases) discharged from a process vessel. At
primary copper smelters, the potential sources of process HAP emissions
are the exhaust gas streams from copper concentrate drying, copper
smelting, and copper converting operations. Process HAP emissions from
the copper concentrate dryer are generated by the entrainment of
particulate matter containing HAP in the exhaust gas stream from the
dryer. A second source of process HAP emissions is the metal compound
vapors in the off-gases exhausted from the flash smelting furnace. At
those smelters operating slag cleaning vessels, process HAP emissions
are released in the off-gases exhausted from the slag cleaning vessel.
Process HAP emissions from the batch copper converters result when off-
gases exhausted during blowing are not captured and controlled.
2. Process Fugitive HAP Emissions
Process fugitive emissions are those emissions associated with a
particular process that are released directly from the process but are
not emitted through a flue or duct in the process exhaust gas stream.
At primary copper smelters, the potential sources of process fugitive
HAP emissions primarily are associated with the flash smelting and
batch copper converting operations. Hot fumes and gases containing
metallic HAP are intermittently released when molten copper matte and
slag are tapped from the flash smelting furnace or a slag cleaning
vessel. Process fugitive HAP emissions from batch copper converters
result when the off-gases generated during blowing escape capture. In
the case of the Pierce-Smith converter design, this can be due to
leakage around the primary hood. Improper ventilation system operation
will allow off-gases to escape from the open converter mouth in the
case of the Hoboken converter design. Also, process fugitive HAP
emissions from either copper converter design can result during those
times that the converter contains molten material and is rolled out
from the blowing position. If not captured, process fugitive HAP
emissions will be released to the atmosphere from openings in the
converter building such as roof monitor vents or exhaust fans.
3. Fugitive Dust Emissions
Fugitive dust HAP emissions at primary copper smelters can be
generated when dust from copper concentrate or other materials
containing metallic HAP is released into the outdoor air. The
entrainment of dust containing metallic HAP into the outdoor air may be
caused by natural events (e.g., wind erosion of feed storage piles) or
by operations conducted by the facility personnel. Potential fugitive
dust emission sources at primary copper smelters include: (1) Dust
entrained when transporting on unpaved roads at the smelter site, bulk
copper-concentrate and other materials containing HAP in dump trucks,
front-end loaders, and other vehicles; (2) dust generated when
unloading copper ore concentrates from trucks or railcars; (3) wind
erosion of outdoor material storage piles; (4) dust entrained when
blending copper concentrate with other feed constituents in the bedding
area; and (5) transferring copper ore concentrate or other HAP-
containing materials to or from conveyor systems.
4. Existing Air Emission Controls
Air emission controls presently are used at all of the existing
primary copper smelters in the United States to comply with Federal and
State regulations limiting emissions of SO2 and total
particulate matter (PM). At each of these copper smelters, exhaust
gases from the copper concentrate dryer are vented to either a baghouse
or electrostatic precipitator (ESP) for control of PM emissions.
Emissions of SO2 are controlled by venting the process off-
gases from flash smelting furnaces and batch copper converters to a
contact sulfuric acid production process. At those smelters operating
slag cleaning vessels, SO2 emissions are controlled by
venting the process off-gases to wet scrubbers. In addition to these
air emission controls, each smelter operates different combinations of
other types of controls for certain process fugitive sources and
fugitive dust sources to comply with requirements imposed by the
individual State standards and air permit conditions applicable to the
smelter.
C. Relationship to Other Rules
The EPA has promulgated national emission standards applicable to
primary copper smelters under two previous Clean Air Act rulemakings.
[[Page 19586]]
The first rule is the new source performance standards (NSPS) for
primary copper smelters (40 CFR part 60, subpart P). This NSPS
establishes a PM emission limit for new copper concentrate dryers and
an SO2 emission limit for new smelting furnaces and new
copper converters. The NSPS does not specifically address HAP emissions
from primary copper smelters.
The second rule applicable to primary copper smelters is the
national emission standards for inorganic arsenic emissions from
primary copper smelters (40 CFR part 61 subpart O). This rule
establishes air emission control requirements for primary copper
smelters at which the total annual average arsenic charging rate to the
copper converters at the smelter is equal to or greater than 75
kilograms per hour (kg/hr). This rule was promulgated in 1986 before
the changes to the NESHAP regulatory program required by the 1990
Amendments. Also, since the rule's promulgation date, the primary
copper smelter industry has changed significantly with the industry-
wide conversion to flash smelting technologies and a number of smelter
closings. None of the primary copper smelters presently operating in
the United States processes copper ore concentrates with arsenic
content levels that require smelter owners and operators to meet the
air emission control standards under subpart O (i.e., the annual
average total arsenic charging rate for the copper converter department
at each smelter is less than 75 kg/hr).
IV. NESHAP Decision Process
A. Source of Authority for NESHAP Development
The amended section 112 of the Act replaces the EPA's previous
NESHAP development system of pollutant-by-pollutant health-based
regulations that proved ineffective at controlling the high volumes and
concentrations of HAP in air emissions. The 1990 Amendments readdress
this deficiency by requiring the EPA to develop NESHAP by first
establishing control technology-based standards for those sources
emitting HAP, and that these control technology-based standards may
later be reduced further to address residual risk that may remain even
after implementing the technology-based controls.
B. Criteria for Development of NESHAP
The statutory directives set out in section 112 of the Act require
NESHAP to be established for control of HAP emissions from both new and
existing sources. The statute requires that the standards reflect the
maximum degree of reduction of 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.
Emission reductions may be accomplished through 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 section 112(h), or (5) a combination of the above. [See
section 112(d)(2).]
To develop a NESHAP, the EPA collects information about the source
category, including information on the emission source characteristics,
control technologies, data from HAP emissions tests at well-controlled
facilities, and information on the costs and other energy and
environmental impacts of emission control techniques. The EPA uses this
information to analyze possible regulatory approaches.
Although NESHAP are normally formatted in terms of numerical
emission limits, alternative approaches are sometimes necessary. In
some cases, for example, physically measuring emissions from a source
may be impossible, or at least impractical, because of technological
and economic limitations. Section 112(h) authorizes the Administrator
to promulgate a design, equipment, work practice, or operational
standard, or a combination thereof, in those cases when it is not
feasible to prescribe or enforce an emissions standard.
If sources in a given source category are major sources of HAP
emissions, then section 112 requires the EPA to establish national
emission standards for these sources based on application of maximum
achievable control technology (MACT). The regulation of the area
sources in a source category, if any, is at the discretion of the EPA.
If there is a finding by the EPA of a threat of adverse effects on
human health or the environment from the area sources, then the source
category can be added to the list of area sources to be regulated.
C. Determining the MACT Floor
After the EPA has identified the specific source categories or
subcategories of major sources to regulate under section 112, it must
set MACT standards for each category or subcategory. Section 112 limits
the EPA's discretion by establishing a minimum baseline or ``MACT
floor'' for these 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, as determined by the Administrator. [See section
112(d)(3).]
The MACT standards for existing sources can be less stringent than
MACT 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 (excluding certain sources) for categories
and subcategories with 30 or more sources, or the best-performing 5
sources for categories or subcategories with fewer than 30 sources.
[See section 112(d)(3).]
After the MACT floor has been determined for a new or existing
source in a source category or subcategory, the Administrator must set
standards that are no less stringent than the MACT floor. Such
standards must then be met by all major sources within the category or
subcategory.
Section 112(d)(2) specifies that the EPA shall establish MACT
standards that require the maximum degree of reduction in emissions of
hazardous air pollutants
* * * that the Administrator, taking into consideration the cost of
achieving such emission reduction, and any non-air quality health
and environmental impacts and energy requirements, determines is
achievable* * *
In establishing MACT standards, the Administrator may distinguish among
classes, types, and sizes of sources within a category or subcategory.
[See section 112(d)(1).] For example, the Administrator could establish
two classes of sources within a category or subcategory based on size
and establish a different emission standard for each class, provided
both standards are at least as stringent as the MACT floor for that
class of sources.
The next step in establishing MACT standards is the investigation
of regulatory alternatives. With MACT standards, only alternatives at
least as stringent as the MACT floor may be selected. Information about
the source category is analyzed to evaluate national impacts, including
HAP emission
[[Page 19587]]
reduction levels, costs, energy, and secondary impacts. Several
regulatory alternative levels (which may be different levels of
emissions control or different levels of applicability or both) are
then evaluated to select the regulatory alternative that best reflects
the appropriate MACT level.
The selected alternative may be more stringent than the MACT floor,
but the control level selected must be technically achievable. In
selecting a regulatory alternative that represents MACT, the EPA
considers the achievable emission reductions of HAP (and possibly other
pollutants that are co-controlled), cost, and economic impacts, energy
impacts, and other environmental impacts. The objective is to achieve
the maximum degree of emissions reduction without unreasonable economic
or other impacts. [See section 112(d)(2).] The regulatory alternatives
selected for new and existing sources may be different because of
different MACT floors, and separate regulatory decisions may be made
for new and existing sources.
The selected regulatory alternative is then translated into a
proposed rule. The rule implementing the MACT decision typically
includes sections on applicability, standards, test methods and
compliance demonstration, monitoring, reporting, and recordkeeping. The
preamble to the proposed rule provides an explanation of the rationale
for the decision. The public is invited to comment on the proposed rule
during the public comment period. Based on an evaluation of these
comments, the EPA reaches a final decision and promulgates the final
rule.
V. Summary of the Proposed Standards
A. Applicability
The proposed NESHAP applies to owners and operators of copper
smelters for which both of the following applicability conditions
apply: (1) the facility produces anode copper by first flash smelting
of copper ore concentrates to obtain molten copper matte and then
converting the molten matte to blister copper using batch copper
converters, and (2) the facility is a major source of HAP as defined in
40 CFR 63.2. If either one of these two conditions do not apply to a
given smelter, then the owner and operator of the smelter would not be
subject to the proposed NESHAP.
The first applicability condition requires that the copper smelter
produces blister copper using batch copper converters. For the purpose
of implementing the rule, a ``batch copper converter'' would be defined
as one of the following copper converter designs: a Pierce-Smith
converter; a Hoboken converter; or a similar design copper converter
that produces blister copper in discrete batches using a sequence of
charging, blowing, skimming, and pouring steps. A batch copper
converter does not use continuous flash converting technology. Thus,
the owner and operator of a copper smelter that uses continuous flash
copper converters would not be not subject to the proposed NESHAP (the
rationale for this decision is presented in Section II of this
preamble).
The second applicability condition requires that the copper smelter
be a major source of HAP emissions, as defined in 40 CFR 63.2. This
means the copper smelter emits or has the potential to emit,
considering application of air emission controls, 10 tpy or more of any
single HAP compound or 25 tpy or more of any combination of HAP
compounds. The proposed NESHAP would not apply to a copper smelter that
is not a major source as defined by the EPA.
B. Sources To Be Regulated
The proposed NESHAP establishes air emission control requirements
for specific HAP emission sources operating at a primary copper smelter
subject to the rule. The HAP emission sources that would be affected by
this rule are: (1) The copper concentrate dryer, (2) the flash smelting
furnace, (3) the slag cleaning vessel, if used at a smelter, (4) the
batch copper converters, and (5) the fugitive dust sources associated
with the handling and storage of copper concentrate and other materials
containing metallic HAP.
For the purpose of implementing the rule with respect to batch
copper converters, the affected source would be the entire copper
converter department. This area would be defined in the rule to be all
of the batch copper converters and the associated capture systems used
to collect gases and fumes emitted during copper converter operations
(e.g., primary hood ventilation system, secondary hood ventilation
system if used).
C. Emission Limits and Requirements
1. Copper Concentrate Dryers
The proposed standards establish emission limits for particulate
matter contained in the exhaust gases discharged from each affected
copper concentrate dryer. Separate emission standards would be
established for existing sources and new sources. The standard would
limit the concentration of particulate matter discharged from existing
copper concentrate dryers to no more than 50 milligrams per dry
standard cubic meter (mg/dscm) (approximately 0.022 grains per dry
standard cubic foot (gr/dscf)). New copper concentrate dryers would be
limited to no more than 23 mg/dscm (approximately 0.01 gr/dscf) of
particulate matter. The rule would allow an owner or operator to use
any type of particulate control device (i.e., baghouse, electrostatic
precipitator, or wet scrubber) that meets the applicable PM emission
limit.
2. Smelting Furnaces
The proposed standards for smelting furnaces are the same for both
existing sources and new sources. The proposed rule requires the
SO2 rich off-gases from the smelting furnace to be vented to
a by-product sulfuric acid plant or other type of sulfur recovery
process unit that requires comparable levels of gas stream conditioning
and pre-cleaning to remove particulate matter. The rationale for
proposing an equipment standard for this source is described in section
VII.C.3 of this document. In addition, the proposed rule requires that
the hot metal vapors and fumes released when tapping molten matte or
slag from the smelting furnace be captured using good ventilation
practices (e.g., use of local ventilation hoods over the tapping port
and launder) and vented to a control device. Particulate matter
emissions from the control device would be limited to no more than 16
mg/dscm (approximately 0.007 gr/dscf).
3. Slag Cleaning Vessels
The proposed NESHAP establishes standards for those primary copper
smelters that operate slag cleaning vessels as part of the copper
smelting process. The requirements of proposed standards would be the
same for existing sources and new sources. Particulate matter emissions
contained in the off-gases exhausted from a slag cleaning vessel would
be limited to no more than 46 mg/dscm (approximately 0.02 gr/dscf). As
an alternative to complying with this standard, the rule would allow an
owner or operator to exhaust the off-gases from the slag cleaning
vessel directly to the by-product sulfuric acid plant (or other type of
sulfur recovery process unit) used to control the off-gases from the
smelting furnace.
Like the standards for smelting furnaces, the proposed rule also
requires that the hot metal fume emissions released when tapping molten
matte or slag from the slag cleaning vessel be captured using good
ventilation
[[Page 19588]]
practices and vented to a suitable control device. Consistent with the
standards for smelting furnaces, PM emissions from this control device
would be limited to no more than 16 mg/dscm (approximately 0.007 gr/
dscf).
4. Batch Copper Converters
The proposed NESHAP establishes emission standards for particulate
matter and visible emissions from the batch copper converters at
primary copper smelters subject to the rule. Separate standards would
be established for existing sources and new sources. For existing
sources, the proposed NESHAP establishes standards requiring that
particulate matter emitted from the copper converters during blowing be
captured and vented to a suitable control device. Different standards
for existing sources would be established based on the type of copper
converter designs used at the primary copper smelters (i.e., Pierce-
Smith converters or Hoboken converters). For new sources, the proposed
NESHAP establishes standards requires that particulate matter emitted
from the copper converters during all operating modes be captured and
vented to a suitable control device. The same standards for new sources
would apply regardless of the design of the copper converters used at a
smelter.
Existing Pierce-Smith Converters. The proposed standards for
existing Pierce-Smith converters require that SO2 rich off-
gases generated during blowing be captured by a primary hood
ventilation system and vented directly to the by-product sulfuric acid
plant (or other type of sulfur recovery process unit) used to control
the SO2 rich gases exhausted from the smelting furnace.
Additional capture devices (e.g., secondary hoods) vented to a control
device would be required to collect PM emissions that escape capture by
the primary hood as needed to achieve the visible emission limit
established for the copper converter department. Particulate matter
emissions from the control device would be limited to no more than 16
mg/dscm (approximately 0.007 gr/dscf).
The proposed rule requires that the primary hood and any
supplemental capture system used to comply with the requirements of the
rule be operated with sufficient ventilation draft such that the
visible emissions exiting the roof monitors or roof exhaust fans on the
building housing the copper converter department do not exhibit an
average opacity greater than 3 percent as determined using the test
protocol specified in the rule. (This test protocol is described later
in this section under ``Performance Testing Requirements''). The owner
or operator would be required to subsequently operate the capture
system such that the system maintains the operating settings
established at the time the owner or operator initially demonstrates
compliance with this visible emission limit. Failure to do so would be
a violation of the standard. The visible emission limit would apply
only at those times when a performance test is conducted while
establishing the capture system operating settings.
Existing Hoboken Converters. The proposed standards for existing
Hoboken converters require that the SO2-rich off-gases be
evacuated directly from the interior of the copper converter (through
the converter's side flue intake) to the by-product sulfuric acid plant
(or other type of sulfur recovery process unit) used to control the
SO2-rich gases exhausted from the smelting furnace. In
addition, the proposed rule requires that the side flue intake of each
Hoboken copper converter be operated with sufficient ventilation draft
during blowing such that the visible emissions exiting the roof
monitors on the building housing the copper converter department do not
exhibit an average opacity greater than 4 percent. Compliance with this
visible emission limit would be demonstrated by following the same
requirements and procedures described above for existing Pierce-Smith
converters.
New Copper Converters. During the periods when a copper converter
is positioned for blowing, the proposed standards for new sources
require that the SO2-rich off-gases generated during blowing
be captured and vented directly to the by-product sulfuric acid plant
(or other type of sulfur recovery process unit) used to control the
SO2-rich gases exhausted from the smelting furnace. In
addition, the proposed rule requires that the capture system be
designed and operated with sufficient ventilation draft whenever molten
material is in the copper converter such that no visible emissions exit
the building housing the copper converter department. The rule would
require these captured gas streams to be vented to a suitable control
device. Particulate matter emissions from the control device would be
limited to no more than 16 mg/dscm (approximately 0.007 gr/dscf).
The proposed visible emission limit would provide flexibility by
allowing the owner or operator to choose the capture system design to
be used at a given smelter. The capture system design could use
multiple intake and duct segments through which the ventilation rates
are controlled independently of each other and individual duct segments
could be connected to separate control devices (e.g., use of individual
secondary air curtain hoods on each copper converter in combination
with a building evacuation system). The occurrence of visible emissions
from the building housing the copper converter department would be
determined using Method 22 in appendix A of 40 CFR part 60.
5. Fugitive Dust Sources
Under the proposed NESHAP, the owner or operator of a primary
copper smelter subject to the rule is required to control fugitive dust
emissions according to a site-specific plan. This written plan would be
prepared by the owner or operator and would describe the specific
control measures that are used to limit fugitive dust emissions from
the individual sources at the smelter site. The duty of the owner or
operator to operate the smelter according to the fugitive dust control
plan would be incorporated into the operating permit for the smelter
site that is issued by the designated permitting authority under 40 CFR
part 70 (the actual fugitive dust control plan for a given smelter
would not be part of the permit).
The proposed rule defines a fugitive dust source as a source of PM
emissions resulting from the handling, storage, transfer, or other
management of solid copper-bearing materials defined in the rule where
the source is not associated with a specific process, process vent, or
stack. Fugitive dust emissions can be generated by a variety of
different operations conducted at a primary smelter, such as dump truck
traffic on smelter roadways; unloading of copper concentrates from dump
trucks or railcars; wind erosion of outdoor piles used to store copper
concentrate; blending of copper concentrate and other feed constituents
in the bedding area; and uncovered conveyor systems used to transfer
copper concentrate. Examples of control measures that could be included
in the written fugitive dust control plan include, but are not limited
to: erecting a building or other enclosure over the copper concentrate
bedding area; covering conveyor systems and using local ventilation
hoods vented to a control device at the conveyor transfer points;
placing copper concentrate stockpiles below grade or installing wind
screens or wind fences around the stockpiles; and spraying water or
applying appropriate dust suppression agents on smelter roadways or
outdoor storage piles.
[[Page 19589]]
6. Equivalent Standard for Combined Exhaust Gas Streams
At some existing primary copper smelters, exhaust gas streams from
several sources are combined before being discharged to a single
control device. The proposed rule addresses this situation by including
an equation with which the owner or operator calculates the allowable
PM emission limit for the combined exhaust gas stream based on the
individual PM emission limits specified in the rule and the volumetric
flow rates for the affected source gas streams composing the combined
exhaust gas stream. This equivalent PM emission limit could be applied
to a combined gas stream that contains any combination of the gas
streams from the following affected sources: (1) exhaust gas stream
from a copper concentrate dryer; (2) exhaust gas stream from a smelting
vessel tapping port capture system; (3) exhaust gas stream from a slag
cleaning vessel tapping port capture system; and (4) exhaust gas stream
from a Pierce-Smith copper converter capture system other than the
primary hood capture system (e.g., secondary hood, building evacuation
system).
D. Compliance and Maintenance Requirements
1. Compliance Dates
Compliance with the air emission control standards under the NESHAP
would be required within 2 years from the date of promulgation for
existing sources and at startup for new or reconstructed sources. An
``existing source'' is a source that commenced construction or
reconstruction before today's date. Sources that commence construction
or reconstruction on or after today's date would be considered to be a
``new source.''
2. Operation and Maintenance Requirements
At all times, including periods of startup, shutdown, and
malfunction, the owner or operator would be required to operate and
maintain each affected source, including associated air pollution
control equipment, according to the requirements in section 63.6 in the
NESHAP general provisions (40 CFR part 63, subpart A). As part of the
written startup, shutdown, and malfunction plan required by section
63.6(e)(3), the owner or operator would be required to include a
description of the corrective action procedures to be implemented to
restore a malfunctioning capture system or control device to proper
operation.
E. Performance Testing Requirements
1. Particulate Matter Emission Performance Tests
Compliance with each of the PM emission limits in the proposed rule
would be determined by performance tests that the owner or operator
performs according to the NESHAP general provisions in Sec. 63.7 under
40 CFR part 63, subpart A, and using specific EPA reference test
methods. For each performance test, the sampling locations would be
determined using EPA Method 1; the stack gas velocity and volumetric
flow rate would be determined using EPA Method 2; and the gas analysis
would be performed using EPA Methods 3 and 4. Each of these methods is
included in appendix A to 40 CFR part 60. Measuring PM emissions would
be performed using EPA Method 5, ``Determination of Particulate Matter
Emissions from Stationary Sources'', in 40 CFR part 60, appendix A
(Method 5D would be required for positive pressure baghouses). The
average of three test runs (each run having a minimum sampling time of
60 minutes and minimum sampling volume of 0.85 dscm) would be used to
determine compliance with the applicable PM emission limit specified in
the rule. During the performance test, the owner or operator also would
establish limits for appropriate control device operating parameters
based on the actual values measured during this test.
2. Visible Emission Performance Tests
Existing Copper Converters. Compliance of existing Pierce-Smith or
Hoboken copper converters with the applicable visible emission limit
would be demonstrated using a specific test protocol that is being
proposed in the rule. The proposed protocol is based on performing a
series of opacity readings during specific copper converter operations
using Method 9, ``Visual Determination of the Opacity of Emissions from
Stationary Sources,'' in 40 CFR part 60, appendix A. The opacity
observations would be made by a team of two qualified visible emission
observers during the period when the primary copper smelter is
operating under conditions representative of the smelter's normal
blister copper production rate.
The total time of the observation period would be of sufficient
duration to obtain a minimum of 20 uninterrupted 6-minute intervals
during which opacity readings made using Method 9 (i.e., 24 readings,
each reading made at a 15-second interval) are recorded for those
conditions when at least one copper converter is operating in the
blowing mode with no visible emission interferences from other smelter
operations occur as specified in the rule. The total observation period
may be divided into two or more segments performed on different days if
a change in the outdoor conditions or copper production conditions
prevents the required number of opacity readings from being obtained
during one continuous period.
Throughout the opacity observation period, an additional person
familiar with the primary copper smelter operation is stationed inside
the building housing the copper converters to visually monitor the
copper converter operations. These indoor process monitors maintain a
log recording the process information. During the observation period,
the owner or operator also would establish minimum or maximum limiting
values, as appropriate, for selected capture system operating
parameters based on the actual values measured during the test.
Upon completion of the opacity observations, the data recorded by
the outdoor opacity observers and the indoor process monitors are
summarized in a tabular format that is specified in the rule. Next, 6-
minute average opacity values are calculated for all periods listed in
the data summary table composed of six consecutive minutes of blowing
with no interferences. A minimum of twenty 6-minute periods are
required for the compliance calculation (if more than twenty 6-minute
periods are included in the data summary table, then all of the 6-
minute periods included in the table would be used for the compliance
calculation). These twenty 6-minute periods (or more if applicable) are
averaged to obtain a single opacity value to determine compliance with
the visible emission limit applicable to a given smelter. Refer to the
proposed rule text for more information regarding the test conditions,
test notification requirements, procedure for conducting the opacity
observations and gathering the converter process information, and the
methods to be used for data reduction and calculation of the average
opacity value.
New Copper Converters. Compliance of new copper converters with the
no visible emission limit specified in the proposed rule would be
demonstrated using Method 22, ``Visual Determination of Fugitive
Emissions from Material Sources and Smoke Emissions from Flares,'' in
appendix A of 40 CFR part 60. Method 22 requires only a determination
as to whether a visible emission occurs and does not require
[[Page 19590]]
that the opacity of the emissions be determined. A minimum observation
period of no less than 2 hours during normal copper production
operations is proposed for the performance test.
F. Inspection and Monitoring Requirements
1. Capture System Inspections
Regular visual inspections of all capture systems used to comply
with the standards would be required under the proposed NESHAP. The
owner or operator would be required to conduct at least once per month
a visual inspection of each capture system operated to meet standards
under the rule. These inspections would involve visually inspecting all
of the capture system components to check for any defects or damage
that could diminish or impair capture system performance. Examples of
these defects or damage include, but are not limited to: openings
through which gas can escape as indicated by the presence of cracks,
holes, or gaps in hoods or ductwork; flow constrictions caused by dents
or accumulated dust in ductwork; and reduced fan performance as
indicated by fan blade erosion. If a defect is detected, then the owner
or operator would be required to replace or repair the defective or
damaged components consistent with the measures for corrective action
detailed in the facility startup, shutdown and malfunction plan.
Completion of the repair would be required as soon as practical but no
later than 30 calendar days after the date the defect is detected.
Delay of repair beyond 30 calendar days of detecting the capture system
defect would be allowed under special circumstances as specified in the
rule.
2. Capture System Monitoring
Monitoring of appropriate operating parameters would be required
for the copper converter capture system operated to comply with the
converter building visible emission limit. No monitoring requirements
for other capture systems operated at the smelter (e.g., smelting
furnace tapping port and launder capture systems, slag cleaning vessel
tapping port and launder capture systems) would be specified under the
proposed rule.
The rule would not specify the individual operating parameters to
be monitored by the owner or operator for the copper converter capture
system. Instead, each owner or operator would be required to select a
set of operating parameters appropriate for the capture system design
used at the smelter that the owner or operator determines to be a
representative and reliable indicator of the range within which the
equipment can operate and achieve the visible emission limit. During
the initial performance test to demonstrate compliance of the copper
converter capture system with the applicable visible emission limit,
the owner or operator would establish minimum operating parameter
limits (or a maximum operating parameter limit if appropriate) for
selected capture system operating parameters. The rule would require
that the owner or operator install, calibrate, operate, and maintain
monitoring devices equipped with a recorder to measure and record at
15-minute or more frequent intervals the actual value for each
operating parameter for which operating limits are established. In
cases when the monitoring regimen includes periodic checking by
facility workers of the capture system fan motor amperages and damper
positions, checks are to be made at least once-per-shift.
The owner or operator would be required to regularly inspect the
data recorded by the monitoring system at a sufficient frequency to
ensure the capture system continues to operate properly. If the
recorded actual value of a selected operating parameter is less than
the minimum operating parameter limit (or, if applicable, greater than
the maximum operating parameter limit) established for the parameter,
then an excursion would be determined to have occurred. The proposed
rule requires that within 1 hour of detecting the excursion, the owner
or operator initiate the corrective action procedures identified in the
startup, shutdown, and malfunction plan as necessary to restore the
operation of the capture system to the proper operating settings.
Failure to take the necessary corrective actions to correct the
operating problem would be a violation of the standard. Also, for a
given operating parameter, if excursions occur six times in any semi-
annual reporting period, then any subsequent excursion of that
operating parameter during the reporting period would be a violation of
the standard. For the purpose of determining the number of excursions
in a semi-annual reporting period, only one excursion would be counted
in any given 24-hour period.
3. Control Device Inspection and Monitoring
Baghouses. For each baghouse used to comply with the PM emission
limits, the owner or operator would be required to operate the baghouse
according to a written standard operating procedures (SOP) manual. This
SOP manual would be prepared by the owner or operator, and the manual
would describe in detail the inspection, maintenance, bag leak
detection, and corrective action procedures to be implemented by the
owner or operator for the baghouse. Specific inspection, maintenance,
and monitoring requirements to be included by the owner or operator in
the SOP manual are specified in the proposed rule. The proposed rule
also requires the use of a bag leak detector system equipped with an
audible alarm. Failure by the owner or operator to operate and maintain
the baghouse according to the requirements specified in the SOP manual
would be a violation of the standard. The inspection and monitoring
requirements would not apply to a baghouse that is included in the
smelter's fugitive dust control plan and exclusively operated to
control fugitive dust emissions.
Venturi Wet Scrubbers. If an owner or operator elects to use a
venturi wet scrubber to comply with a PM emission limit, the proposed
rule requires that the owner or operator monitor the scrubber pressure
drop and water flow rate. During the initial performance test to
demonstrate compliance with the applicable standard, the owner or
operator would establish minimum operating values for each of these
parameters based on the actual values measured during this test. The
rule would require that the owner or operator install, calibrate,
operate, and maintain monitoring devices equipped with a recorder to
measure and record at 15-minute or more frequent intervals the actual
value for each operating parameter. An excursion would be determined to
have occurred when the recorded actual value of the scrubber pressure
drop or water flow rate is less than the minimum operating limit
established for the parameter during the compliance test. Any excursion
would be a violation of the standard.
Other Control Devices. If an owner or operator elects to use a
control device other than a baghouse or venturi wet scrubber to comply
with a PM emission limit (e.g., an ESP), the proposed rule requires
that the owner or operator monitor appropriate operating parameters for
the control device. The rule would not specify the individual operating
parameters to be monitored. Instead, each owner or operator would be
required to select a set of operating parameters appropriate for the
control device design that the owner or operator determines to be a
representative and reliable indicator of the control device
performance. During the initial performance test to demonstrate
compliance with the applicable standard, the owner or operator would
[[Page 19591]]
establish limiting values for selected operating parameters based on
the actual values measured during this test. The rule would require
that the owner or operator install, calibrate, operate, and maintain
monitoring devices equipped with a recorder to measure and record at
15-minute or more frequent intervals the actual value for each
operating parameter for which operating limits are established. The
owner or operator would be required to regularly inspect the data
recorded by the monitoring system at a sufficient frequency to ensure
the control device is operating properly. An excursion occurs when the
recorded actual value of a selected operating parameter is less than
the minimum operating parameter limit (or, if applicable, greater than
the maximum operating parameter limit) established for the parameter.
When an excursion occurs, the owner or operator would be required to
initiate the corrective action procedures identified in the startup,
shutdown, and malfunction plan as necessary to restore the operation of
the control device to the proper operating settings. Failure by the
owner or operator to take the necessary corrective actions would be a
violation of the standard.
G. Notification, Recordkeeping, and Reporting Requirements
The proposed rule requires the owner or operator to comply with the
notification, recordkeeping, and reporting requirements in the general
provisions in subpart A of 40 CFR part 63 with one exception. The
notification, recordkeeping, and reporting requirements in the general
provisions related directly to the visible emission limit compliance
provisions specified in 40 CFR 63.6(h) would not apply to this rule.
1. Notifications
The owner or operator would be required to submit notifications
described in the general provisions (40 CFR part 63, subpart A), which
include initial notification of applicability, notifications of
performance tests, and notification of compliance status.
2. Records
The owner or operator would be required to maintain records
required by the general provisions and records needed to document
compliance with the standard. For each control device used to comply
with the rule, records would include copies of inspection records and a
copy of the written maintenance plan.
The owner or operator would be required to retain all records for
at least 5 years following the date of each occurrence, measurement,
maintenance, corrective action, report, or record. The records for the
most recent 2 years must be retained on site; records for the remaining
3 years may be retained off site but must still be readily available
for review. The files could be retained on microfilm, microfiche, on a
computer, or on computer or magnetic disks. The owner or operator could
report required information on paper or a labeled computer disk using
commonly available and compatible computer software.
3. Reports
As required by the general provisions, the owner or operator would
be required to submit a report of performance test results; develop and
implement a written startup, shutdown, and malfunction plan and report
semi-annually any events where the plan was not followed; and submit
semi-annual reports of any excursions when any monitored parameters
fall outside the range of values established during the performance
test.
VI. Impacts of Proposed Rule
A. Health Impacts
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).] As previously explained, Congress specified in the
1990 Amendments that each standard for major sources require the
maximum reduction in emissions of HAP that the EPA determines is
achievable considering cost, health and environmental impacts, and
energy impacts. 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 playing field, ensuring that facilities that employ
cleaner processes and good emissions control are not disadvantaged
relative to competitors with poorer controls.
Emission data collected during development of the proposed NESHAP
show that the pollutants that are listed in section 112(b)(1) and are
emitted by primary copper smelters in the largest quantities are
arsenic and lead compounds. Other HAP that are emitted in lesser
quantities include antimony, beryllium, cadmium, chromium, cobalt,
manganese, nickel, and selenium. These toxic metals can cause effects
such as mucous membrane irritation (e.g., bronchitis, decreased lung
capacity), gastrointestinal effects, nervous system disorders (from
loss of function to tremor and numbness), skin irritation, and
reproductive and developmental disorders. Chronic inhalation exposure
to arsenic compounds is strongly associated with lung cancer; chronic
oral exposure is linked to skin, bladder, liver, and lung cancer.
Additionally, several of the metals accumulate in the environment and
the human body. Cadmium, for example, is a cumulative pollutant, which
can cause kidney effects after the cessation of exposure. Similarly,
the onset of effects from beryllium exposure may be delayed 3 months to
15 years. Many of the metals also are known (arsenic, chromium VI,
certain nickel compounds) or probable (cadmium, lead, and beryllium)
human carcinogens.
In addition to HAP, the proposed rule would also reduce some of the
pollutants whose emissions are controlled under the National Ambient
Air Quality Standards (NAAQS). These pollutants include particulate
matter and lead. The health effects of these pollutants 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. Children are particularly sensitive and
exposure can also result in reduced growth. Lead compounds can be
persistent in the environment and have the potential to accumulate in
food chains.
The EPA does recognize 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 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) pollution
specific characteristics (e.g., toxicity, half-life in the environment,
bioaccumulation, and persistence).
[[Page 19592]]
B. Air Quality Impacts
Nationwide HAP emissions from the ``Primary Copper Smelting''
source category are estimated to be approximately 189 Mg/yr (208 tpy).
The EPA estimates that implementation of the NESHAP, as proposed, would
reduce these nationwide HAP emissions by approximately 20 percent to
155 Mg/yr (171 tpy).
C. Other Environmental and Energy Impacts
Other environmental and energy impacts associated with implementing
the requirements of the proposed rule primarily are expected to result
from the operation of the capture systems and the PM control devices.
No significant adverse water, solid waste, or energy impacts are
expected as a result of the proposed rule.
Direct water quality impacts from the proposed rule would vary
depending on the type of control devices that the smelter owners and
operators choose to use to comply with the proposed particulate matter
emission limits. No direct water quality impacts would result from
operation of either a baghouse or electrostatic precipitators. If wet
scrubbers are used to control PM emissions, wastewater from the
scrubber blowdown would be generated. The EPA expects wet scrubbers to
be used only in limited applications to comply with the rule (the most
likely use of existing wet scrubbers is to meet the standards for slag
cleaning vessels).
The dust collected in baghouses and electrostatic precipitators and
the sludge generated by wet scrubbers would be potential sources of
solid waste. At existing primary copper smelters, the common operating
practice is to recycle the dust collected by the baghouses and
electrostatic precipitators by feeding the material back to the flash
smelting furnace and not dispose of this material as a solid waste.
Energy impacts would result from the increased consumption of
electricity required at a primary copper smelter to operate any
additional capture systems and control devices installed to meet the
proposed rule requirements. Electricity is required to charge the
collector plates in electrostatic precipitators. Electric motor-driven
fans, blowers, or pumps, (depending on the type of control equipment)
are used for operations such as moving the captured gas stream to the
control device, operating baghouses, and circulating water through a
wet scrubber.
D. Economic Impacts
The cost impacts of the proposed NESHAP are expected to result
mainly from costs that some primary copper smelters may incur to
replace or upgrade their existing copper converter secondary capture
systems (e.g., install a new secondary hood design or increase the
system draft by installing a larger fan) and costs for monitoring,
recording, and recordkeeping. The EPA estimated the cost to owners and
operators of implementing the requirements of the proposed rule at the
smelter sites that the EPA expects are likely to be subject to the
rule. The total nationwide capital investment cost to purchase and
install the air emission controls that would be required by the rule is
estimated by the EPA to be approximately $6 million. The total
nationwide annual cost would be approximately $2.2 million per year.
Emission control costs as a percentage of sales revenues were
estimated to evaluate the impact of the regulation on the primary
copper smelting industry and affected individual facilities. Economic
impacts are expected to be minimal. The annualized costs of the
regulation represents approximately 0.07 percent of 1996 sales revenues
for the industry. Individual copper smelting facilities are expected to
experience emission control costs as a percent of sales ranging from
0.01 to 0.44 percent.
VII. Rationale for Selection of Proposed Standards
A. Selection of Pollutants
For the proposed NESHAP, the EPA decided that it is not practical
to establish individual standards for each specific type of metallic
HAP the could be present in a copper ore (e.g., separate standards for
arsenic emissions, separate standards for lead emissions, and so forth
for each of the metals listed as HAP and potentially could be present
in the copper ore). When released into the air during the primary
copper smelting operations, each of the metallic HAP compounds behaves
as particulate matter. Therefore, the EPA decided to establish
standards for total particulate matter as a surrogate pollutant for the
individual types of metallic HAP emitted from primary copper smelters.
The type and concentration of the metallic HAP compounds contained
in the copper ore concentrate shipped to a primary copper smelter is
not constant but instead varies over time. The concentrations of each
type of metallic HAP frequently vary throughout the copper ore deposit
from which the copper concentrate is obtained. Establishing separate
standards for each individual type of metallic HAP would impose costly
and significantly more complex compliance and monitoring requirements
on the primary copper smelter owners and operators and would achieve
little, if any, more HAP emission reduction than would be achieved
using the surrogate pollutant approach based on total particulate
matter. On the other hand, strong correlations exist between air
emissions of the selected surrogate pollutant and emissions of the
individual metals it represents. The control technologies used for the
control of PM emissions achieve equivalent levels of performance on
metallic HAP emissions. Therefore, standards requiring good control of
particulate matter will also achieve good control of the metallic HAP
emitted from primary copper smelters.
B. Selection of Affected Sources
For the purpose of implementing a NESHAP, an affected source is
defined to mean the stationary source, or portion of a stationary
source that is regulated by a relevant standard or other requirement
established under section 112 of the Act. Each relevant standard is to
designate the ``affected source'' for the purpose of implementing that
standard. Within a source category, the EPA decides which HAP emission
sources (i.e., emission points or groupings of emission points) are
most appropriate for establishing separate emission standards in the
context of the Clean Air Act statutory requirements and the industry
operating practices for the particular source category. The EPA
selected the specific HAP emission sources requiring the development of
air standards under this rulemaking based on consideration of test data
and HAP emission estimates for these individual emission points.
The EPA reviewed available information regarding HAP emissions from
anode copper fire refining operations. The information is insufficient
to specifically quantify the level of HAP emissions from the anode
furnaces and anode casting operations. However, at this stage of the
copper production process, the residual content of metallic HAP in the
blister copper is very low. Therefore, EPA decided not to propose
specific emission standards for anode copper fire refining operations.
The EPA considered different approaches for designating the
``affected source'' for the selected emission point types ranging from
using a broad definition (e.g., the entire smelter site) to narrow
definitions (e.g., individual emission points). Designating the
affected source for the NESHAP as the entire smelter site was dismissed
by the EPA. This approach would require that the MACT floor be
established by the
[[Page 19593]]
total smelter-wide HAP emissions indicative of the level that is
achieved by the best-performing five existing smelters. Application of
a single MACT floor to combinations of different process and fugitive
emission points at a primary copper site would be difficult.
A second approach is to designate an affected source by grouping
the same or similar types of emission points together under a single
affected source designation. The EPA decided that grouping similar
emission points was the appropriate approach to use for two of primary
copper smelter HAP emission sources selected to be controlled: batch
copper converters and fugitive dust sources.
At each of the existing primary copper smelters, a row of three to
five batch copper converters are used to produce blister copper. Off-
gases captured from each of the individual converters during blowing
are exhausted to the sulfuric acid plant through a common ventilation
system used for the entire group of converters. At those smelters
currently operating secondary capture devices (e.g., secondary hoods or
air curtains) on each of the copper converters, the secondary captured
gas streams are vented to a separate control device. Considering the
smelter operating practices and existing air pollution control
configurations used for copper converters, the EPA decided it is
appropriate to designate the entire group of copper converters as the
affected source.
Fugitive dust sources are those sources of PM emissions at the
primary copper smelter resulting from the handling, storage, transfer,
or other management of copper concentrate or other materials containing
metallic HAP where the source is not associated with a specific
process, process vent, or stack. The type and number of individual
fugitive dust sources varies from smelter-to-smelter. Therefore, the
EPA decided it is appropriate to designate the entire group of fugitive
dust sources as the affected source.
The narrowest designation of affected source is by individual
emission point. At each of the existing primary copper smelters only
one copper concentrate dryer and one flash smelting furnace (or flash
smelting furnace and slag cleaning vessel combination) is used at the
smelter site. Each of these individual emission points would
potentially emit significant quantities of HAP emissions if not
controlled. Therefore, the EPA decided to designate each individual
copper concentrate dryer, smelting furnace, and slag cleaning vessel as
a separate affected source.
C. Selection of Basis and Level of the Proposed Standards
1. Background
The Clean Air Act statutory requirements for determination of the
MACT floor are explained in section IV.C of this document.
Determination of MACT floor for existing sources is dependent on the
nationwide number of existing sources within the source category. The
source category for which the EPA is developing this NESHAP is
comprised of six existing primary copper smelters nationwide (discussed
in Section III.A of this preamble). For a source category with less
than 30 existing sources, the MACT floor is the average emission
limitation achieved by the best performing five existing sources. The
MACT floor for new sources is defined by the emission control that is
achieved in practice by the best-controlled source.
For the other NESHAP developed by the EPA to date, the Agency has
used several different approaches to determine MACT floor for
individual source categories depending on the type, quality, and
applicability of available data. These approaches include determining a
MACT floor based on: (1) emission test data that characterize actual
HAP emissions from presently controlled sources included in the source
category; (2) existing federally-enforceable emission limitations
specified in air regulations and facility air permits applicable to the
individual sources comprising the source category; or (3) application
of a specific type of air emission control technology currently being
used by sources in the source category or by sources with similar
pollutant stream characteristics. For the ``Primary Copper Smelting''
source category, the EPA decided to use the approach best suited for
establishing the MACT floor on an individual affected source basis.
Once the MACT floors are determined for new and existing sources in
a source category, the EPA must establish standards under a NESHAP that
are no less stringent than the applicable MACT floors. The
Administrator may promulgate standards that are more stringent than the
MACT floor when such standards are determined by the EPA to be
achievable taking into consideration the cost of implementing the
standards as well as any non-air quality health and environmental
impacts and energy requirements.
Section 112 of the Act requires that emission standards for control
of HAP be established unless it is the Administrator's judgment that
emission standards cannot be established or enforced for a particular
type of source. In those cases when it is not possible to establish or
enforce an emission standard, an alternative format must be used.
Section 112(h)(2) of the Act identifies two conditions under which the
Administrator may use an alternative format: (1) If the pollutants
cannot be emitted through a conveyance designed and constructed to emit
or capture the pollutant; or (2) if the application of measurement
technology to a particular class of sources is not practicable because
of technology and economic limitations. In these cases, the EPA may
instead establish design, equipment, work practice, or operational
standards, or a combination of these.
2. Selection of Standards for Copper Concentrate Dryers
Emissions of HAP from the copper concentrate dryer result from the
entrainment of particulate matter containing metallic HAP in the
exhaust gas stream from the dryer. At all six existing copper smelters,
PM emissions from copper concentrate dryers are controlled by venting
the dryer exhaust gases to either a baghouse or ESP. All six of the
existing copper concentrate dryers have federally enforceable PM
emission limits. Four of the dryers are subject to the NSPS PM emission
limit of 50 mg/dscm (0.022 gr/dscf) (See Sec. 60.162 in 40 CFR part 60,
subpart P). The other two dryers are subject to a PM emission limit
established in each smelter's respective State air permit. One dryer is
subject to a State permit PM emission limit of 0.01 gr/dscf
(approximately 23 mg/dscm). The second dryer is subject to a State
permit PM emission limit of 0.03 gr/dscf limit (approximately 69 mg/
dscm). The EPA also has obtained copies of the results for the
compliance tests for each of these sources. Upon consideration of the
information available to the EPA, the Agency elected to select the MACT
floor for copper concentrate dryers based on the federally enforceable
PM emission limits.
Using the federally-enforceable PM limits for the top five
controlled sources, the average PM emission limit for existing copper
concentrate dryers is 0.45 mg/dscm. The median limit for the five
sources is the NSPS level of 0.50 mg/dscm. The average and median
values are essentially the same and represent the control level
established by the NSPS. Therefore, the EPA selected the NSPS PM
emission limit of 50 mg/dscm as the MACT floor control level for
existing copper concentrate dryers.
[[Page 19594]]
The EPA established a separate MACT floor control level for new
sources based on the best-controlled copper concentrate dryer. As
discussed above, the federally-enforceable PM emission limit for the
best-controlled existing source is 0.01 gr/dscf. Converting this value
to metric units, the MACT floor control level selected for new copper
concentrate dryers is the PM emission limit of 23 mg/dscm.
The format of both the existing NSPS and State standards for copper
concentrate dryers is a numerical emission limit using a mass
concentration limit format. Consistent with the directives of section
112(h) of the Act, the EPA selected a mass concentration limit format
for the proposed standards.
The MACT floor control level selected for existing copper
concentrate dryers is 50 mg/dscm. The EPA considered establishing
regulatory alternatives more stringent than the MACT floor control
level based on the actual emissions recorded during compliance testing
at each source. After review of the available test data for the
controlled sources, the EPA concluded that these test data indicate
actual PM emissions from each of the six controlled copper concentrates
dryers effectively are at or near the control level established for the
MACT floor. Therefore, EPA selected the MACT floor level of 50 mg/dscm
as the proposed PM emission limit for an existing copper concentrate
dryer.
The MACT floor control level selected for new copper concentrate
dryers is the PM emission limit of 23 mg/dscm. The EPA did not identify
any regulatory alternatives beyond the MACT floor for new sources.
Therefore, the EPA selected the MACT floor of 23 mg/dscm (0.01 grain/
dscf) as the level for the proposed standard for new copper concentrate
dryers.
3. Selection of Standards for Smelting Furnaces
The smelting of copper concentrate in a furnace to obtain copper
matte results in two types of HAP emissions. Process HAP emissions from
the flash smelting furnace are metallic compound vapors in the off-
gases exhausted from the furnace. Process fugitive HAP emissions result
from hot metal vapors released when molten copper matter or slag is
tapped from the furnace. Separate standards are proposed for smelting
furnace process HAP emissions and for process fugitive HAP emissions.
Process HAP Emissions. All six of the existing smelters operate
some type of flash smelting furnace. Process HAP emissions from these
furnaces are controlled by exhausting the SO2 rich off-gases
to a by-product sulfuric acid plant. These controls have been installed
to comply with requirements established to meet the National Ambient
Air Quality Standards (NAAQS) for SO2 and, in five of the
six smelters, the primary copper smelter NSPS (40 CFR 60 subpart P).
The smelting furnace at the Phelps Dodge Hidalgo smelter is not subject
to this NSPS standard because it was built before the effective date of
the standard. The NSPS limits SO2 emissions from affected
smelting furnaces to no more than 650 parts per million. All
requirements under the NSPS as well as the applicable State
Implementation Plans (SIP) are federally-enforceable.
While the by-product sulfuric acid plants were originally installed
at the smelters for controlling SO2 emissions, the inherent
design and operating requirements of these plants also provide
effective control of the metallic HAP contained in the smelting furnace
off-gases. The sulfuric acid production process involves the catalytic
conversion of the SO2 contained in the off-gases to produce
liquid sulfuric acid. To optimize the process performance and prevent
expensive damage to the catalysts and other critical process equipment,
the first step of the process requires that the smelting furnace off-
gases be pre-cleaned and conditioned. Typically, these pre-cleaning and
conditioning operations involve first passing the gas stream through an
ESP (to remove particulate matter) and then a wet scrubber (to remove
particulate matter further and to reduce the gas stream temperature).
By using multiple control devices in series, very high overall
particulate matter removal efficiencies are achieved such that
effectively no particulate matter (and, therefore no metallic HAP) are
emitted in the tail gas from the sulfuric acid plant.
Considering that all existing smelters use the same control
technology for the smelting furnace off-gases, the EPA elected to
select the MACT floor for smelting furnaces process HAP emissions based
on application of a specific air emission control technology being used
by the existing sources in the source category. The MACT floor control
level selected for process HAP emissions from existing smelting
furnaces is to vent the SO2 rich off-gases from the smelting
furnace to a by-product sulfuric acid plant or other type of sulfur
recovery process unit that requires comparable levels of gas stream
conditioning and pre-cleaning to remove particulate matter. Since all
of the existing smelting furnaces represent the best-controlled source,
the new source MACT floor is the same as the existing source MACT floor
for smelting furnace process HAP emissions. Furthermore, the EPA did
not identify any regulatory alternatives beyond the MACT floor.
Therefore, the EPA selected the MACT floor as the basis for a proposed
standard to control HAP emissions from smelting furnace off-gases at
both new and existing sources.
To prescribe numerical emission limits for metals or particulate
matter in the tail gases from the by-product sulfuric acid plants
operated at primary copper smelters is very difficult because any
actual emissions of metals or particulate matter from the by-product
sulfuric acid plant, if present at all, are very variable and occur in
trace amounts. Section 112 of the Act requires that an emission
standard for control of HAP be established except in those cases when
it is the Administrator's judgement that it is not feasible to
prescribe or enforce an emission standard. In this case, it is neither
feasible nor practical to prescribe or enforce a numerical emission
limit for gases vented to a sulfuric acid plant due to technological
and economic limitations. Because rigorous precleaning and conditioning
of the smelting furnace off-gases is a necessary operating condition
for the by-product sulfuric acid plant, venting to this unit ensures
that emissions of metallic and particulate matter HAPs are either
nonexistent or limited to trace amounts. In such a case, it is neither
feasible nor practical to prescribe, measure, and enforce a numerical
emission limit for the by-product sulfuric acid plant at these emission
levels and, not only would such a standard be essentially unworkable
from a technical standpoint, it would also provide virtually no
benefit.
As an alternative to establishing a numerical emission limit, the
EPA is proposing an equipment-based format for the standard. The
proposed standard requires that the off-gases from the smelting furnace
be vented to a by-product sulfuric acid plant or other type of sulfur
recovery process unit that requires comparable levels of gas stream
pre-cleaning and conditioning to remove particulate matter. The NSPS
and SIP requirements for each smelter already provide for continuous
emission monitoring of SO2 emissions from these by-product
sulfuric acid plants to assure compliance and proper operation of the
plants. When indicated by the SO2 emission monitoring, the
smelter owners and operators are required to implement appropriate
corrective actions as necessary to prevent degradation of the by-
product sulfuric
[[Page 19595]]
acid plant performance. The EPA believes that the mandatory gas stream
pre-cleaning requirements imposed by this equipment standard together
with the continuous SO2 monitoring required by other
federally-enforceable air rules assures that a consistently very high
level of metallic HAP control is achieved for the off-gases exhausted
from smelting furnaces without the need to establish a specific
emission standard and perform emission testing to demonstrate
compliance with the standard.
Fugitive Process HAP Emissions. At five of the six existing
smelters, the hot metal vapors released during matte and slag tapping
are captured using local hood ventilation systems. Because these
emissions occur intermittently (only when matte or slag tapping is
performed) and have relatively low SO2 concentrations, the
capture gas stream is not vented to the sulfuric acid plant but instead
is vented to a separate baghouse or ESP. At the sixth smelter, the
matte and slag tapping emissions are currently captured by a local
ventilation hood system and vented to the smelter's main stack.
Not all of the controlled sources have federally enforceable PM
emission limits. Four of the sources are subject to State air permit
limits; however these PM emission limits vary in format and the type of
particulate regulated, and therefore cannot be averaged together. The
test data for these controlled sources are highly variable. The
characteristics of the captured gas streams from smelting furnace matte
and slag tapping operations are similar to the gas streams captured by
Pierce-Smith converter secondary hood systems (e.g., same HAP
constituents, similar particulate matter loadings, relatively low
SO2 concentrations, and emitted intermittently). Therefore,
the EPA elected to establish the MACT floor for smelting furnace matte
and slag tapping operations based on application of the control devices
to a similar controlled source (i.e., lean SO2 gas streams
captured by Pierce-Smith copper converter secondary hood systems).
The MACT floor control level selected for control devices used to
treat lean SO2 gas streams from Pierce-Smith copper
converters is a PM emission limit of 16 mg/dscm (the rationale for this
level is described later in this section). Applying the same MACT floor
to smelting furnaces, the MACT floor control level selected for
smelting furnace process fugitive emission sources is a PM emission
limit of 16 mg/dscm. No best-controlled smelting furnace could be
identified by the EPA. Therefore, the new source MACT floor is the same
as the existing source MACT floor.
The format selected for the standard is a numerical emission limit
expressed as a mass concentration of particulate matter. The EPA did
not identify any regulatory alternatives beyond the MACT floor for
existing sources nor could the EPA identify a best-controlled source.
Therefore, EPA selected the MACT floor of 16 mg/dscm as the level for
the PM emission limit proposed for both existing and new smelting
furnace matte and slag tapping operations.
4. Selection of Standards for Slag Cleaning Vessels
Two existing primary copper smelters operate a slag cleaning vessel
in conjunction with the flash smelting furnace. At one of these
smelters, the slag cleaning vessel currently is not being used as part
of the smelting process, but representatives of the smelter have told
the EPA that operation of this slag cleaning vessel may be resumed in
the future.
Process HAP Emissions. The existing air emission control used for
the slag cleaning vessels is to exhaust the off-gases from the slag
cleaning vessel to a wet scrubber for control of sulfur oxide gases and
particulate matter. One source is subject to a State air permit
emission limit of 0.02 gr/dscf. The EPA's review of the available
particulate matter emission test data for the wet scrubbers concluded
that the data are limited, highly variable, and should not be used to
characterize the actual emission levels for the purpose of establishing
the MACT floor. The EPA elected to select the MACT floor for slag
cleaning vessel exhaust gases based on the federally enforceable
emission limit of 0.02 gr/dscf. Converting this value to metric units,
the MACT floor control level selected for existing slag cleaning
vessels is the PM emission limit of 46 mg/dscm.
The format selected for the standard is a numerical emission limit.
The EPA did not identify any regulatory alternatives beyond the MACT
floor for existing sources nor could the EPA identify a best-controlled
source. Therefore, the EPA selected the MACT floor of 46 mg/dscm as the
level for the PM emission limit proposed for the off-gases exhausted
from existing and new slag cleaning vessels.
Process Fugitive HAP Emissions. Like smelting furnaces, process
fugitive HAP emissions from slag cleaning vessels occur when molten
copper matte or slag is tapped from the vessel. No data exists for
these systems. At the one smelter currently operating a slag cleaning
vessel, the hot metal vapors captured by the hood ventilation system
over the slag cleaning vessel tapping ports are exhausted into the same
control system used for the smelting furnace process fugitive
emissions. Based on the application of air emission controls used by
sources with similar pollutant stream characteristics, the MACT floor
control level selected for slag cleaning vessel matte and slag tapping
operations is the same PM emission limit of 16 mg/dscm established for
smelting furnaces.
The format selected for the standard is a numerical emission limit.
The EPA did not identify any regulatory alternatives beyond the MACT
floor for existing sources nor could the EPA identify a best-controlled
source. Therefore, EPA selected the MACT floor of 16 mg/dscm as the
level for the PM emission limit proposed for both existing and new slag
cleaning vessel matte and slag tapping operations. This is the same
limit selected for control devices used to treat lean SO2
gas streams from Pierce-Smith copper converters as described in the
next section.
5. Selection of Standards for Batch Copper Converters
Selection of Regulatory Approach. Two different batch converter
designs currently are used at primary copper smelters in the United
States. The majority of the smelters use the Pierce-Smith converter
design while one smelter uses the Hoboken converter design. These two
designs differ significantly in the method used to capture the
converter off-gases for air emission control. The side-flue design of
the Hoboken converter evacuates the gases directly from the interior of
the converter shell. In contrast, the design of the Pierce-Smith
converter relies totally on the use of external hood systems positioned
over the converter mouth to capture the gases after they have already
exited the converter shell. These air emission capture methods are
integrated into the overall design of each type of converter and are
not interchangeable between the two designs (i.e., a Pierce-Smith
converter cannot readily be retrofitted to use the Hoboken design).
Thus, the EPA concluded that it is not appropriate to group the Hoboken
converters with the Pierce-Smith converters for the purpose of
establishing standards for existing batch copper converters. The EPA
decided to develop separate standards for existing Pierce-Smith
converters and for existing Hoboken converters.
Visual observations by EPA representatives of the converter capture
systems in operation at each of the
[[Page 19596]]
smelters suggests that the capture efficiency varies from smelter-to-
smelter because different capture system designs and operating
practices are used at individual smelters. No data are available to
determine a specific capture efficiency for the capture systems used
for either Pierce-Smith converters or Hoboken converters. In lieu of
having specific capture efficiency values, the EPA believes that the
opacity of the visible emissions exiting the converter building roof
vents or exhaust fans directly over the converter aisle is a direct
function of converter capture system performance when the converters
are operating under certain specific conditions. Thus, the approach
selected by the EPA for establishing a MACT floor for the converter
capture system performance is to use opacity and converter operating
data gathered at each of the smelters during a series of site visits
conducted by the Agency.
Converter Visible Emission Observations. In April and May of 1997,
the EPA conducted a series of visible emission observations at existing
primary copper smelters in the United States operating Pierce-Smith
converters or Hoboken converters. A summary of protocol used for the
field observation data collection and analysis is presented below. More
detailed information about the site visits, the opacity observations,
and EPA's analysis of the data are available in Docket No. A-96-22.
Visible emission readings of the converter building at each of the
smelter sites were made by teams of certified observers. At the three
primary copper smelters located in Arizona, opacity observations were
made by a team of EPA observers and a team of observers from the State
of Arizona Department of Environmental Quality. The opacity
observations for the two smelters located in New Mexico were made by a
team of EPA observers.
All of the opacity observations were performed using procedures
specified in Method 9 in 40 CFR part 60, appendix A. The observers
recorded opacity readings at 15-second intervals for those sections of
the converter building roof monitor (or in the case of one smelter, the
converter building roof exhaust fan outlets) that are positioned
directly over the location of the copper converters inside the
building. When it was possible for an observer to see two or more
plumes emitted from the converter building roof during the same reading
interval, the observer identified the plume having the highest opacity
and recorded an opacity reading for that plume.
Throughout the periods when outdoor opacity observations were being
made by the observer teams, an EPA representative familiar with primary
copper smelter operations was stationed inside the converter building
and visually monitored the copper converter operations. This observer
recorded on a clock time basis the times when a converter was in the
blowing position and times when events occurred which generated visible
plumes inside the building. Additional information about the converter
operations was obtained from the smelter's computer records of the
individual converter blowing rates.
In general, a sufficient number of opacity observations were
obtained during the site visits to obtain a data base for each smelter
consisting in the range of 400 to 500 minutes of opacity readings. Not
included in the data base prepared for each smelter were any opacity
readings made during periods when the converter operations were judged
to not be representative of normal smelter operations (e.g., converter
capture system malfunction) or when the opacity observation conditions
did not meet Method 9 criteria (e.g., occurrence of high winds).
The analysis of the field data began by creating a spreadsheet data
file for each smelter listing by the clock time at 1-minute intervals
an average opacity value (based on the outside EPA and State observer
opacity readings) and corresponding converter process information
(based on the indoor process monitor log and records of the converter
system blowing rates provided by the smelter operator). The 1-minute
opacity value was calculated by averaging all of the 15-second readings
made by the EPA and State observers during the clock time minute
interval.
The EPA considered alternative approaches for determining an
average opacity value for each smelter to represent the converter
capture system performance. For each smelter data file, the EPA
identified those clock minute intervals when one or more converters are
operating in the blowing mode and none of the following ladle transfer
operations were indicated in the file to be occurring in the converter
aisle: charging of matte, reverts, or other materials to a converter;
converter slag skimming from a converter; blister copper pouring from a
converter; or slag return to the furnace. To account for the time delay
between when visible emissions generated in the converter building are
seen by the inside observer and when these impact the opacity recorded
by the outside observers, the two minutes of opacity readings recorded
immediately following the clock time recorded for cessation of the
activity were assumed to be impacted by the visible emission event. The
set of conditions when at least one of the converters is operating in
the blowing mode and no visible emission events have occurred in the
converter aisle during the preceding two minutes is referred to as
``blowing without interferences''. The EPA then calculated the average
opacity value for each period consisting of 6 consecutive minutes
during which ``blowing without interferences'' occurred.
Existing Pierce-Smith Copper Converters. Five existing primary
copper smelters use Pierce-Smith converters. At each smelter, the air
emissions from these copper converters during blowing are captured and
controlled. The design and operation of the overall capture system used
at each of these smelters to collect these emissions from Pierce-Smith
converters varies from smelter-to-smelter. At every smelter, whenever
each Pierce-Smith converter is positioned for blowing, the mouth of the
converter is covered by a close-fitting primary hood. The gas stream
captured by the primary hood is vented to the by-product sulfuric acid
plant at the smelter. However, the primary hood does not completely
seal the converter mouth since sufficient space must be provided to
rotate the converter mouth out from under the hood during charging,
skimming, and at other times.
To collect emissions that escape capture by the primary hoods,
capture devices of various designs in addition to the primary hoods are
used at each of the existing smelters (hereafter referred to
collectively as the ``converter secondary capture system''). At four of
the smelters, the converter secondary capture system consists of a
second set of mechanical hoods (hereafter referred to as the
``secondary hoods'') positioned above the primary hoods. The secondary
hoods used at the individual smelters vary in design, capture
effectiveness, and operating practices.
The fifth smelter controls air emissions from its Pierce-Smith
converter operations using a secondary air curtain hood for each
individual converter and also evacuates the entire converter building
to a baghouse. This capture system design effectively provides 100
percent capture of all converter process fugitive emissions (as well as
those process fugitive emissions and fugitive dust emissions from other
sources located inside the converter building). The State air permit
requirement for this capture system is to operate with no visible
emissions.
The approach selected by the EPA for establishing the MACT floor
for the overall Pierces-Smith converter capture
[[Page 19597]]
system performance is to use opacity of the visible emissions from the
converter building. The results for the EPA's field visible emission
observations (described in the preceding section) were used to quantify
the MACT floor control level. At the four smelters using primary hoods
with secondary hoods to capture converter process fugitive emissions,
the average converter building opacity observed at each of the
individual smelters ranged from 0.7 percent to 7.1 percent. At the
fifth smelter converter process fugitive emissions are controlled using
secondary air curtain hoods in combination with a building evacuation
system. Based on the State air permit requirement that the building
evacuation system operate with no visible emissions, the EPA set the
average converter building opacity for this smelter to be zero percent.
The arithmetic average of the opacity values for the five smelters
operating Pierce-Smith converters is 2.8 percent. To establish the MACT
floor, the EPA rounded this average opacity value to the nearest whole
opacity value and selected 3 percent as the MACT floor converter
capture system performance level for Pierce-Smith copper converters.
The EPA did not identify any regulatory alternatives beyond the MACT
floor for existing sources. Therefore, EPA selected the MACT floor of 3
percent as the level for the visible emission limit proposed for
existing Pierce-Smith converters.
To establish the MACT floor for the level of control achieved for
each of the captured converter gas streams, the EPA selected the
approach of basing the MACT floor on application of the air emission
control technology being used by the existing sources in the source
category. Separate MACT floors were selected for the gas streams
captured by the converter primary hoods and for the gas streams
captured by the converter secondary capture system.
At each of the existing smelters, the SO2 rich off-gases
generated during converter blowing and captured by the primary hoods
are blended with the off-gases from the smelting furnace and then
vented to the smelter's by-product sulfuric acid plant. None of these
converters is subject to the primary copper smelter NSPS (40 CFR 60
subpart P). Nonetheless, the control of the converter primary off-gases
(i.e., SO2 rich off-gases generated during converter
blowing) is required under each smelter's SIP for attainment of the
NAAQS for SO2.
Given that the SO2 rich off-gases exhausted from the
Pierce-Smith converters and smelting furnace are treated by the same
controls (i.e., the by-product sulfuric acid plant), it follows that
the MACT floor for the converters should be the same as the MACT
selected for the smelting furnace off-gases. As presented in section
VII.C.3 of this preamble, the standard that the EPA selected for
smelting furnaces is to vent the furnace off-gases to a by-product
sulfuric acid plant (or other type of sulfur recovery process unit that
requires comparable levels of gas stream pre-cleaning and conditioning
to remove particulate matter). Therefore, the EPA selected the same
MACT floor and standard for gas streams captured by the Pierce-Smith
converter primary hoods.
The low SO2 concentrations of gas streams captured by
the Pierce-Smith converter secondary capture systems are not suitable
for venting to the by-product sulfuric acid plant. Instead, PM
emissions from the gas streams captured by the Pierce-Smith converter
secondary capture systems (hereafter referred to as ``converter
secondary emissions'') are controlled at each of the existing smelters
by venting the gas streams to a separate control device. At four of the
smelters operating Pierce-Smith copper converters, the converter
secondary capture system is vented to a baghouse. At the fifth smelter,
the converter secondary capture system is vented to an ESP.
Considering that four of the five existing smelters use the same
control technology for the Pierce-Smith converter secondary emissions,
the MACT floor control level selected for Pierce-Smith converter
secondary emissions is to vent the captured gas streams to a baghouse
(or other type particulate matter control device that achieves a
comparable level of control for particulate matter emissions). Since
this control technology also represents the best-controlled source, the
new source MACT floor is the same as the existing source MACT floor for
Pierce-Smith converter secondary emissions.
The EPA did not identify any regulatory alternatives beyond the
MACT floor for control of gas streams captured by the converter
secondary capture systems. Therefore, the EPA selected the application
of baghouses as the basis for the proposed standards to control
converter secondary emissions. Consistent with other standards the EPA
has promulgated based on application of baghouses for control of PM
emissions, the EPA selected the format of the standard to be a
numerical emission limit expressed using a mass concentration.
The EPA used available test data to select a value for the
numerical emission limit for Pierce-Smith converter secondary
emissions. Particulate matter emission test data are available for each
of the existing baghouses used to control Pierce-Smith converter
secondary emissions. A data set consisting of results for three
individual source test runs are available for each of the four
baghouses. The results for these individual test runs show baghouse
outlet PM concentrations range from approximately 0.002 gr/dscf to 0.01
gr/dscf. Averaging the results of the three individual runs for each
baghouse shows that comparable levels of particulate matter emission
control are achieved by all of the baghouses (the average baghouse
outlet PM concentrations ranging from approximately 0.004 gr/dscf to
0.007 gr/dscf). Test results for a three-run source test are also
available for the single ESP used to control Pierce-Smith converter
secondary emissions. The ESP outlet PM concentrations measured by the
three individual test runs range from approximately 0.002 gr/dscf to
0.004 gr/dscf. The data show that the ESP achieved a level of PM
emission control similar to that demonstrated by the baghouses.
All of the control devices were operating properly when the source
tests were conducted. Considering that the gas stream flow rates and
inlet particulate matter concentrations varied between the individual
control devices, the EPA cannot distinguish any real differences
between the control levels measured for the control devices used to
control Pierce-Smith converter secondary emissions. Therefore, for the
numerical emission limit, the EPA selected the value at the upper end
of the range of the average outlet PM concentrations in the data set
(0.007 gr/dscf). It is the EPA's judgement that a control device outlet
PM concentration of 0.007 gr/dscf best characterizes the level of
actual emissions that can reasonably be expected to be consistently
achieved by all well-controlled sources. Converting this value to
metric units, the proposed standard for both existing and new sources
selected for Pierce-Smith converter secondary emissions is the PM
emission limit of 16 mg/dscm.
Existing Hoboken Copper Converters. One existing copper smelter
uses Hoboken converters. The off-gases from these copper converters
during blowing are evacuated through the side-flue and vented to the
sulfuric acid plant at the smelter. At this smelter, the average
converter building opacity value observed by the EPA was 3.8 percent.
The MACT floor converter capture system performance level selected for
[[Page 19598]]
Hoboken copper converters is an average opacity value of 3.8 percent as
measured at the converter building roof monitor using the test protocol
developed by the EPA for this rulemaking. To be consistent with the
method used to select the MACT floor for Pierce-Smith converters, the
EPA rounded this average opacity value to the nearest whole opacity
value and selected 4 percent as the MACT floor converter capture system
performance level for Hoboken copper converters. The EPA did not
identify any regulatory alternatives beyond the MACT floor for existing
sources. Therefore, EPA selected the MACT floor of 4 percent as the
level for the visible emission limit proposed for existing Hoboken
converters.
Like the Pierce-Smith converters, the SO2 rich off-gases
exhausted from the Hoboken converters during converter blowing is
blended with the off-gases stream from the smelting furnace and vented
to the by-product sulfuric acid plant. For consistency with the Pierce-
Smith converter standards, the EPA established the proposed standard
for existing Hoboken converters to be that the SO2 rich off-
gases directly evacuated from the converters be vented to a by-product
sulfuric acid plant or other type of sulfur recovery process unit that
requires comparable levels of gas stream conditioning and pre-cleaning
to remove particulate matter.
New Copper Converters. The EPA established a separate standard for
new batch copper converters based on the best-controlled source. This
source is the smelter that controls air emissions from the copper
converter operations using secondary air curtain hoods and evacuation
of the entire converter building to a baghouse. This capture system
design effectively provides 100 percent capture of all converter
emissions. The federally-enforceable opacity limit for the converter
building at this smelter is no visible emissions. Although this capture
system presently is used at a smelter operating Pierce-Smith
converters, the capture system design is equally applicable to a
smelter operating Hoboken converters. Therefore, the MACT floor capture
system performance selected for any new batch copper converter,
regardless of design, is to operate with sufficient ventilation draft
whenever molten material is in the copper converter such that no
visible emissions exit the building housing the copper converters.
For the captured gas streams, the control levels achieved by the
best-controlled source are the same as the standards established for
existing converters. Thus, the standard the EPA selected for new
converters is to vent the SO2 rich off-gases from the
converter generated during blowing to a by-product sulfuric acid plant
or other type of sulfur recovery process unit that requires comparable
levels of gas stream conditioning and pre-cleaning to remove
particulate matter. The EPA selected 16 mg/dscm to establish the
proposed PM emission limit for the converter gases not controlled by
venting to the sulfuric acid plant.
6. Selection of Standards for Fugitive Dust Sources
Fugitive dust emissions at existing primary copper smelters are
controlled by using a variety of different methods. Not all smelters
control the same sources nor use the same type of control. The fugitive
dust control measures used at a given smelter varies depending on the
dust controls required by the facility's State air permit and the
facility owner's preferences and polices regarding fugitive dust
control. These controls can range from daily water spraying of plant
roads and outdoor storage piles to enclosure and venting of the source
to a control device. No specific group of fugitive dust control
measures could be identified that reflected an average emission
limitation for the existing smelters. The EPA decided that MACT floor
for fugitive dust sources is to develop and implement a site-specific
set of fugitive dust control measures to be implemented by the smelter
owner or operator according to a written plan. No best-controlled
fugitive dust sources could be identified by the EPA. Therefore, the
new source MACT floor is the same as the existing source MACT floor for
fugitive dust sources.
Establishing and enforcing emission limitations for fugitive dust
sources is not practical. The inherent mechanisms by which pollutants
are emitted from fugitive dust sources prevents the application of
batch stack sampling methods to measure the level of the emissions from
these sources. It is not feasible to capture the emissions and
subsequently discharge these emissions through a duct or other
conveyance to a control device. Therefore, as allowed under section
112(h) of the Act, the EPA decided to use a work practice format for
the proposed standards for fugitive sources.
The proposed standards would require the smelter owner or operator
to implement appropriate work practice control measures specific to the
types of fugitive dust sources at a smelter site. For many fugitive
dust sources there are several equivalent control measures available
for controlling fugitive dust emissions from a particular type of
source. Therefore, the standard for each affected owner or operator to
develop and implement a site-specific fugitive dust control plan is
being proposed rather than the EPA establishing the specific individual
work practices that all smelter owners and operators must use. The EPA
believes that flexibility provided to the smelter owner and operator by
the site-specific approach is needed because the best fugitive dust
control options for a given smelter are determined by the physical
layout of the smelter, the types of fugitive dust sources, and the
control measures that are already being implemented. These factors vary
significantly from smelter to smelter.
D. Selection of Compliance Requirements
1. Selection of Compliance Dates
Section 112(i)(3) of the Act requires the Administrator to
establish a compliance date or dates for each category or subcategory
of existing sources which provides for compliance with the applicable
standards as expeditiously as practicable but in no event later than 3
years after the effective date of the standards. To select the proposed
compliance date for existing affected sources at primary copper
smelters, the EPA considered the time that would be necessary for
owners and operators of existing primary copper smelters to complete
the tasks required to comply with the proposed rule.
At all of the existing smelters, air emission control equipment
capable of meeting the applicable proposed standard is currently in
place for many of the affected sources that would be subject to the
rule. For a few existing affected sources, an upgrade of an existing
capture system or installation of new control equipment may be needed.
Owners and operators* will need to develop and implement the required
operating plan for control of fugitive dust sources, and implement the
required operating and monitoring requirements for the air emission
control equipment used to comply with the standards. The EPA concluded
that it is reasonable to expect that achieving compliance of existing
affected sources with the requirements of the proposed rule can be
completed within a period significantly shorter than 3 years. The EPA
selected the compliance date for existing affected sources at primary
copper smelters to be no later than 2 years after the effective date of
the standards. The EPA believes it is realistic and practical to
accomplish the
[[Page 19599]]
tasks needed to comply with the proposed rule within 2 years, and this
period fulfills the Clean Air Act directive that the Administrator
establish a compliance date which provides for compliance with the
applicable standards as expeditiously as practicable. Furthermore,
should special circumstances arise at an individual smelter such that
installation of controls which cannot be completed within the specified
2-year compliance period, section 63.6(i) of the NESHAP general
provisions already provide for a compliance date extension (allowing up
to 1 additional year for compliance) to be granted upon request of the
owner or operator and approval by the Administrator or the delegated
regulatory authority.
The compliance date for new affected sources was selected by the
EPA to meet the requirements of section 112(i) of the Act. Owners or
operators of new affected sources at primary copper smelters would be
required to achieve compliance upon startup or the effective date of
this NESHAP, whichever is later.
2. Selection of Test Methods
The proposed NESHAP would require the owner or operator to conduct
an initial performance test to demonstrate compliance with each of the
particulate matter emission limits specified in the rule that is
applicable to a given smelter site. In addition, the rule would require
that the owner or operator perform an initial performance test to
determine the visible emissions from the building housing the copper
converter department.
The EPA selected the performance test requirements to demonstrate
compliance with the particulate matter emission limits based on the use
of appropriate EPA reference test methods. Method 5 in appendix A to 40
CFR part 60 is an EPA reference test method that has been developed and
validated for the measurement of PM emissions from stationary sources.
Method 5D is a variation of Method 5 to be used for measuring PM
emissions at the outlet to a positive pressure baghouse. For sampling
and analysis of the gas stream the following EPA reference methods
would be used with Method 5: Method 1 to select the sampling port
location and the number of traverse points; Method 2 to measure the
volumetric flow rate; Method 3 for gas analysis; and Method 4 to
determine stack gas moisture.
As part of this rulemaking, the EPA is proposing a specific test
protocol to be used for determining compliance with the visible
emission limits established for existing Pierce-Smith and Hoboken
copper converters. These standards establish average opacity limits for
the visible emissions exiting the building roof monitors or exhaust
fans directly above the copper converters. The test protocol includes
making opacity readings using the Agency's EPA reference test method
for the measurement of visible emissions from stationary sources
(Method 9 in appendix A of 40 CFR part 60). This method is widely used
in EPA air rules for determining compliance with visible emission
limits. The EPA selected the procedures specified in the proposed test
protocol based on the Agency's experience with the opacity observations
performed during the smelter program the EPA conducted at existing
primary copper smelters. A preliminary draft of the test protocol was
reviewed by the State agencies and copper companies that participated
in the field observation program. Based on comments received by the EPA
from these reviewers, certain refinements to the opacity observation
and data analysis procedures were incorporated into the test protocol
included in the proposed NESHAP.
For determining compliance with the no visible emission limit
proposed for new copper converters, the EPA selected Method 22,
``Visual Determination of Fugitive Emissions from Material Sources and
Smoke Emissions from Flares,'' in appendix A of 40 CFR part 60. Method
22 requires only determination as to whether a visible emission occurs
and does not require that the opacity of the emissions be determined.
This method provides a simpler and less expensive method for
determining compliance with a no visible emission limit than requiring
new sources to use an appropriate version of the test protocol being
proposed for existing sources. So that a performance test using Method
22 would represent a range of the different copper converter operations
that typically occur inside the converter building during normal copper
production, the EPA is proposing a minimum observation period of no
less than 2 hours.
3. Selection of Monitoring Requirements
The EPA evaluates a hierarchy of options to select compliance
assurance monitoring of HAP emissions from affected sources. This
involved identifying and analyzing several different monitoring options
for each of the affected sources and the proposed control equipment.
This hierarchy includes measurement of the HAP or an appropriate
surrogate pollutant by a continuous emission monitoring system (CEMS),
installation of measurement devices for monitoring of process and/or
control device operating parameters, and periodic or one-time
performance tests. Each option is evaluated relative to its technical
feasibility, cost, ease of implementation, and relevance to the process
or air emission control equipment.
The use of a CEMS provides a direct measurement of the emissions
from a given source. Monitors for measuring metallic HAP emissions are
not commercially available. Monitors for measuring PM emissions as a
surrogate for metallic HAP emissions have not yet been demonstrated for
primary copper smelting operations. Therefore, the EPA did not consider
further the use of CEMS for this proposed rule.
Another option for compliance assurance is monitoring appropriate
process and/or control equipment operating parameters. Process
parameters were not selected as indicators for metallic HAP emissions
from the primary copper smelter sources because an adequate correlation
does not exist between production or process parameters and emission
rates. The EPA does believe that reasonable assurance of compliance
with the standards proposed for this NESHAP can be achieved by the
owner or through appropriate periodic inspection and continuous
monitoring of the operation of the air emission control equipment that
has been demonstrated by an initial performance test to achieve the
applicable emission standards under the rule. Therefore, operating
parameters were selected instead for the converter capture system and
for control devices with one exception because measurements outside a
range of values established during an initial performance test can be
used to indicate the control device is not operating properly (i.e.,
not operating at the conditions under which compliance was demonstrated
by performance testing).
A modified approach to monitoring control device operation
parameters was selected for baghouses because the baghouse operating
parameters routinely monitored do not correlate well with the
particulate matter emission rates. The approach selected for baghouses
uses a comprehensive, periodic inspection and maintenance program in
combination with the use of bag leak detectors. The EPA has previously
adopted this baghouse monitoring approach for similar types of
metallurgical industry sources that use baghouses to control
particulate matter emissions (e.g., secondary lead smelting
[[Page 19600]]
NESHAP under 40 CFR part 63, subpart X).
E. Selection of Notification, and Recordkeeping Reporting Requirements
Under section 114(a) of the Act, the EPA may require any owner or
operator of a source subject to a NESHAP to establish and maintain
records as well as prepare and submit notifications and reports to the
EPA. The general recordkeeping, notification, and reporting
requirements for NESHAP are specified in sections 63.9 and 63.10 of the
NESHAP general provisions. The recordkeeping, notification, and
reporting requirements for the proposed NESHAP were selected to be
consistent with the general provisions requirements.
VIII. Public Participation
The EPA seeks full public participation in arriving at its final
decisions, and strongly 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 the 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-96-22 (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 following address, and not to the public docket,
to ensure that proprietary information is not inadvertently placed in
the docket: Attention: Mr. Gene Crumpler, c/o Ms. Melva Toomer, U.S.
EPA Confidential Business Information Manager, OAQPS (MD-13), Research
Triangle Park, NC 27711. Information covered by such a 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 the submission when it is received by the
EPA, the submission may be made available to the public without further
notice to the commenter.
IX. Administrative Requirements
A. Docket
The docket is an organized and complete file of all the information
considered by the EPA in developing 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 case of judicial
review. [See section 307(d)(7)(A) of the Act.]
B. Public Hearing
If a request to speak at a public hearing is received, a public
hearing on the proposed standards will be held according to section
307(d)(5) of the Act. Persons wishing to present oral testimony or to
inquire as to whether a hearing is to be held should contact the EPA
(see FOR FURTHER INFORMATION CONTACT). 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
June 19, 1998. Written statements should be addressed to the Air and
Radiation Docket and Information Center (see ADDRESSES) and refer to
Docket No. A-95-43. 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.
C. ``Significant Regulatory Action'' Determination Under Executive
Order 12866
Under Executive Order 12866 (58 FR 51735, October 4, 1993), the 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.
Under the terms of Executive Order 12866, it has been determined
that this regulatory action is not significant because none of the
listed criteria apply to this action. Consequently, this action was not
submitted to OMB for review under Executive Order 12866.
D. Enhancing the Intergovernmental Partnership Under Executive Order
12875
In compliance with Executive Order 12875, the EPA involved State
regulatory experts in the development of this proposed rule. No tribal
governments are believed to be affected by this proposed rule. Although
not directly impacted by the rule, State governments will be required
to implement the rule by incorporating the rule into permits and
enforcing the rule upon delegation. They will collect permit fees that
will be used to offset the resources burden of implementing the rule.
Comments have been solicited from State partners and 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. Clean Air Act
As directed by 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 rule
will be reviewed 8 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.
F. Paperwork Reduction Act
The information collection requirements in this proposed rule have
been submitted for approval to the 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.
1850.01), and a copy may be obtained from Sandy Farmer, OPPE Regulatory
Information
[[Page 19601]]
Division, U.S. Environmental Protection Agency (2137), 401 M Street
SW., Washington, DC 20460, or by calling (202) 260-2740.
The proposed information requirements are based on notification,
recordkeeping, and reporting requirements in the NESHAP general
provisions (40 CFR part 63, subpart A), which are mandatory for all
owners or operators subject to national emission standards. These
recordkeeping and reporting requirements are specifically authorized by
section 114 of the Act (42 U.S.C. 7414). All information submitted to
the EPA for which a claim of confidentiality is made is safeguarded
according to Agency policy under 40 CFR part 2, subpart B. [See 41 FR
36902.]
The proposed rule would require maintenance inspections of the
control devices but would not require any notifications or reports
beyond those required by the general provisions. The proposed
recordkeeping requirements require only the specific information needed
to determine compliance.
The annual monitoring, reporting, and recordkeeping burden for this
collection (averaged over the first 3 years after the effective date of
the rule) is estimated to be 11,400 labor hours per year at a total
annual cost of $560,500. This estimate includes a one-time performance
test and report (with repeat tests where needed); one-time submission
of a startup, shutdown, and malfunction plan with semi-annual reports
for any event when the procedures in the plan were not followed; semi-
annual excess emission reports; maintenance inspections; notifications;
and recordkeeping. Total capital/startup costs associated with the
monitoring requirements over the 3-year period of the ICR are estimated
at $156,000, with operation and maintenance costs of $72,000/yr.
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 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.
Comments are requested on the EPA's need for this information, the
accuracy of the provided burden estimates, and any suggested methods
for minimizing respondent burden, including the use of automated
collection techniques. Send comments on the ICR 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, DC 20503, marked ``Attention: Desk
Office for EPA.'' Include the ICR number in any correspondence. Because
the OMB is required to make a decision concerning the ICR between 30
and 60 days after April 20, 1998, comment to OMB is best assured of
having its full effect if OMB receives it by May 20, 1998. The final
rule will respond to any OMB or public comments on the information
collection requirements contained in this proposal.
G. Pollution Prevention Act
The Pollution Prevention Act of 1990 (42 U.S.C. 13101 et seq., Pub.
L. 101-508, November 5, 1990) establishes the national policy of the
United States for pollution prevention. This act declares that: (1)
pollution should be prevented or reduced whenever feasible; (2)
pollution that cannot be prevented or reduced should be recycled or
reused in an environmentally-safe manner wherever feasible; (3)
pollution that cannot be recycled or reused should be treated; and (4)
disposal or release into the atmosphere should be chosen only if none
of the other options is available.
The HAP emitted during the copper smelting process result from
metallic compound impurities that occur naturally in copper ore
deposits. The House Conference Report on the 1990 Amendments
specifically prevents the Administrator from considering the
substitution of, or other changes in, metal or mineral bearing raw
material used as feedstocks in establishing emission standards, work
practice standards, operating standards, or other prohibitions for
nonferrous metals source categories. Thus, no restrictions can be
placed by the EPA on the HAP content of the copper ore shipped to
primary copper smelters. Furthermore, there are no commercial-scale
pretreatment processes available for removing or reducing the metallic
HAP contained in the copper concentrate before feeding the material to
the flash smelting furnace.
Opportunities for applying pollution prevention to the ``Primary
Copper Smelting'' source category are basically limited to application
of air emission controls to reduce the release of metallic HAP from the
copper smelting process into the atmosphere. Particulate matter
collected by baghouses or ESP's used to control the HAP emissions from
the smelting processes can be recycled back through the flash smelting
furnace for recovery of the residual copper contained in this material.
Thus, to the extent possible, pollution prevention has been considered
in the development of this rulemaking, and the NESHAP is consistent
with the Pollution Prevention Act.
H. Regulatory Flexibility
The Regulatory Flexibility Act (RFA) generally requires an agency
to conduct a regulatory flexibility analysis of any rule subject to
notice and comment rulemaking requirements unless the agency certifies
that the rule will not have a significant economic impact on a
substantial number of small entities. Small entities include small
businesses, small not-for-profit enterprises, and small government
jurisdictions.
The impact of the regulation on small entities was evaluated in the
economic impact analysis. Companies engaged in primary copper smelting
with less that 1,000 employees are classified as small businesses by
the Small Business Administration. Based on the analysis conducted,
none of the companies owning the six primary copper smelters
potentially affected by this rulemaking are small entities. Under
section 605(b) of the Regulatory Flexibility Act, the Administrator
certifies that this rule will not have a significant economic impact on
small entities.
I. Unfunded Mandates Reform Act
Title II of the Unfunded Mandates Reform Act of 1995 (UMRA), Pub.
L. 104-4, establishes requirements for Federal agencies to assess the
effects of their regulatory actions on State, local, and tribal
governments and the private sector. Under section 202 of the UMRA, the
EPA generally must prepare a written statement, including a cost-
benefit analysis, for proposed and final rules with ``Federal
mandates'' that may result in expenditures by State, local, and tribal
governments, in aggregate, or by the private sector, of $100 million or
more in any one year. Before promulgating an EPA rule for which a
written statement is needed, section 205 of the UMRA generally requires
the EPA
[[Page 19602]]
to identify and consider a reasonable number of regulatory alternatives
and adopt the least costly, most cost-effective, or least burdensome
alternative that achieves the objectives of the rule. The provisions of
section 205 do not apply when they are inconsistent with applicable
law. Moreover, section 205 allows the EPA to adopt an alternative other
than the least costly, most cost-effective, or least burdensome
alternative if the Administrator publishes with the final rule an
explanation of why that alternative was not adopted. Before the EPA
establishes any regulatory requirements that may significantly or
uniquely affect small governments, including tribal governments, it
must have developed under section 203 of the UMRA a small government
agency plan. The plan must provide for notifying potentially affected
small governments, enabling officials of affected small governments to
have meaningful and timely input in the development of EPA regulatory
proposals with significant Federal intergovernmental mandates, and
informing, educating, and advising small governments on compliance with
the regulatory requirements.
The EPA has determined that this rule does not contain a Federal
mandate that may result in expenditures of $100 million or more for
State, local, and tribal governments, in the aggregate, or the private
sector in any one year. Thus, today's rule is not subject to the
requirements of sections 202 and 205 of the UMRA. In addition, the EPA
has determined that this rule contains no regulatory requirements that
might significantly or uniquely affect small governments because it
contains no requirements that apply to such governments or impose
obligations upon them. Therefore, today's rule is not subject to the
requirements of section 203 of the UMRA.
List of Subjects in 40 CFR Part 63
Environmental protection, Air pollution control, Hazardous
substances, Primary copper smelter, Reporting and recordkeeping
requirements.
Dated: April 9, 1998.
Carol M. Browner,
Administrator.
For the reasons set out in the preamble, part 63 of title 40,
chapter I, 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: 42 U.S.C. 7401, et seq.
2. Part 63 is amended by adding subpart QQQ to read as follows:
Subpart QQQ--National Emission Standards for Hazardous Air
Pollutants From Primary Copper Smelters
Sec.
63.1440 Applicability.
63.1441 Definitions.
63.1442 [Reserved]
63.1443 Standards: Copper concentrate dryers.
63.1444 Standards: Smelting vessels.
63.1445 Standards: Slag cleaning vessels.
63.1446 Standards: Copper converters.
63.1447 [Reserved]
63.1448 Standards: Fugitive dust sources.
63.1449 Equivalent standards: combined exhaust gas streams.
63.1450 Compliance with standards and maintenance requirements.
63.1451 Performance testing requirements.
63.1452 Inspection and monitoring requirements.
63.1453 Notification requirements.
63.1454 Recordkeeping and reporting requirements.
63.1455 State authority and delegations.
Appendix A of Subpart QQQ to Part 63--Applicability of General
Provisions (40 CFR part 63, subpart A) to Subpart QQQ.
Figure 1 of Subpart QQQ--Data Summary Sheet for Determination of
Average Opacity.
Subpart QQQ--National Emission Standards for Hazardous Air
Pollutants From Primary Copper Smelters
Sec. 63.1440 Applicability.
(a) The requirements of this subpart apply to the owner or operator
of a facility for which both of the following conditions apply:
(1) The facility produces anode copper by first flash smelting of
copper ore concentrates to obtain molten copper matte and then
converting the molten matte to blister copper using batch copper
converters as defined in Sec. 63.1441 of this subpart.
(2) The facility is a major source as defined in Sec. 63.2 of this
part.
(b) The affected sources at a primary copper smelter subject to
this subpart are the sources listed in paragraphs (b)(1) through (b)(5)
of this section.
(1) Copper concentrate dryers. The affected source is each
individual copper concentrate dryer as defined in Sec. 63.1441 of this
subpart.
(2) Smelting vessels. The affected source is each individual
smelting vessel as defined in Sec. 63.1441 of this subpart.
(3) Slag cleaning vessels. The affected source is each individual
slag cleaning vessel as defined in Sec. 63.1441 of this subpart.
(4) Batch copper converters. The affected source is the copper
converter department as defined in Sec. 63.1441 of this subpart.
(5) Fugitive dust sources. The affected source is the entire group
of all fugitive dust sources, as defined in Sec. 63.1441 of this
subpart, that are located at a primary copper smelter.
(c) A new affected source is an affected source for which
construction or reconstruction commences on or after April 20, 1998.
New affected sources are subject to the relevant standards for new
sources specified in this subpart.
(d) The requirements of the general provisions in subpart A of this
part that apply and those that do not apply to owners and operators
subject to this subpart are specified in appendix A to this subpart.
Sec. 63.1441 Definitions.
All terms used in this subpart shall have the meaning given to them
in this section, Sec. 63.2 of this part, or the Act.
Baghouse means a control device that collects particulate matter by
filtering the gas stream through bags. A baghouse is also referred to
as a ``fabric filter.''
Bag leak detection system means an instrument that can monitor
particulate matter (e.g., dust) loadings in the exhaust of a baghouse
to detect bag failures. A bag leak detection system includes, but is
not limited to, an instrument that operates on triboelectric, light
scattering, transmittance or other effect to monitor relative
particulate matter loadings.
Batch copper converter means a copper converter that is one of the
following copper converter designs: a Pierce-Smith converter; a Hoboken
converter; or a similar design copper converter that produces blister
copper in discrete batches using a sequence of charging, blowing,
skimming, and pouring steps. A batch copper converter does not use
continuous flash converting technology.
Blowing means the copper converter operating mode during which air
or oxygen-enriched air is injected into the molten converter bath.
By-product sulfuric acid plant means a facility that produces
sulfuric acid by a contact process involving the catalytic conversion
of sulfur dioxide to sulfur trioxide followed by absorption of the
sulfur trioxide in a sulfuric acid solution.
[[Page 19603]]
Capture system means the collection of components used to capture
gases and fumes released from one or more emission points, and then
convey the captured gas stream to a control device. A capture system
may include, but is not limited to, the following components as
applicable to a given capture system design: duct intake devices,
hoods, enclosures, ductwork, manifolds, plenums, and fans.
Charging means the copper converter operating mode during which
molten or solid material is added to a copper converter.
Control device means the air pollution control equipment used to
collect particulate matter emissions. Examples of such equipment
include, but are not limited, to a baghouse, an electrostatic
precipitator, and a wet scrubber.
Copper concentrate dryer means a vessel in which copper
concentrates are heated in the presence of air to reduce the moisture
content of the material. Supplemental copper-bearing feed materials and
fluxes may be added or mixed with the copper concentrates fed to a
copper concentrate dryer.
Copper converter means a vessel in which copper matte or other
copper-bearing material is oxidized to form blister copper.
Copper converter department means the area at a primary copper
smelter in which operations are conducted to oxidize copper matte or
other copper-bearing material to form blister copper. The copper
converter department includes the batch copper converters and the
associated capture systems used to collect gases and fumes emitted
during copper converter operations (e.g., primary hood ventilation
system, secondary hood ventilation system).
Copper matte means a material predominately composed of copper and
iron sulfides produced by smelting copper ore concentrates.
Fugitive dust material means copper concentrate, dross, reverts,
slag, speiss, or other solid copper-bearing materials.
Fugitive dust source means a stationary source of particulate
matter emissions resulting from the handling, storage, transfer, or
other management of fugitive dust materials where the source is not
associated with a specific process, process vent, or stack. Examples of
fugitive dust sources include, but are not limited to, plant roadways
used by vehicles transporting copper concentrate, outdoor copper
concentrate storage piles, bedding areas, and conveyor system transfer
points.
Holding means the copper converter operating mode during which the
molten bath is maintained in the copper converter but does not include
periods of blowing or periods when material is being added or removed
from the copper converter.
Opacity means the degree to which emissions reduce the transmission
of light.
Operating parameter monitoring system means the total equipment
that may be required to meet the data acquisition and availability
requirements of this subpart used to sample, condition (if applicable),
analyze, and provide a record of capture system or control device
operating parameters.
Particulate matter means any finely divided solid or liquid
material, other than uncombined water, as measured by the specific
reference method.
Pouring means the copper converter operating mode during which
molten copper is removed from the molten converter bath.
Primary copper smelter means a facility that produces anode copper
by first flash smelting of copper ore concentrates to obtain molten
copper matte and then converting the molten matte to blister copper
using batch copper converters. Primary copper smelting includes the
handling and blending of copper concentrate, the drying of copper
concentrate, the flash smelting of copper concentrate to matte-grade
copper, the conversion of matte-grade copper to blister-grade copper in
a batch copper converter, the refining of blister-grade copper to
anode-grade copper, and the casting of copper anodes.
Skimming means the copper converter operating mode during which
molten slag is removed from the molten converter bath.
Slag cleaning vessel means a vessel that receives molten copper-
bearing material and the predominant use of the vessel is to separate
this material into molten copper matte and slag layers.
Smelting vessel means a furnace, reactor, or other type of vessel
in which copper ore concentrate and fluxes are melted to form a molten
mass of material containing copper matte and slag. Other copper-bearing
materials may also be charged to the smelting vessel.
Sec. 63.1442 [Reserved].
Sec. 63.1443 Standards: Copper concentrate dryers.
(a) The requirements of this section apply to affected copper
concentrate dryers at a primary copper smelter subject to this subpart.
Standards for existing copper concentrate dryers are specified in
paragraph (b) of this section. Standards for new copper concentrate
dryers are specified in paragraph (c) of this section.
(b) The owner or operator shall not discharge nor cause to be
discharged to the atmosphere from the exhaust vent for an existing
copper concentrate dryer any gases that contain particulate matter
greater than 50 milligrams per dry standard cubic meter (mg/dscm) as
determined by a performance test conducted in accordance with the
applicable requirements of Sec. 63.1451 of this subpart.
(c) The owner or operator shall not discharge nor cause to be
discharged to the atmosphere from the exhaust vent for a new copper
concentrate dryer any gases that contain particulate matter greater
than 23 mg/dscm as determined by a performance test conducted in
accordance with the applicable requirements of Sec. 63.1451 of this
subpart.
Sec. 63.1444 Standards: Smelting vessels.
(a) The requirements of this section apply to affected existing and
new smelting vessels at a primary copper smelter subject to this
subpart.
(b) The owner or operator shall discharge the off-gases exhausted
from the smelting vessel to a by-product sulfuric acid plant or another
type of sulfur recovery process that requires comparable levels of gas
stream pre-cleaning and conditioning to remove particulate matter. A
performance test is not required for gas streams that meet the
requirements of this paragraph.
(c) The owner or operator shall capture and control air emissions
when tapping molten material from the smelting vessel in accordance
with the requirements of paragraphs (c)(1) and (c)(2) of this section.
(1) The owner or operator shall install and operate a capture
system to collect gases and fumes released from each opening to the
smelting vessel that is used to tap molten material from the vessel.
The design and placement of this capture system shall be such that the
tapping port opening, launder, and molten material receiving vessel are
positioned within the confines or influence of the system's ventilation
draft during all periods when molten material flows from the tapping
port into the molten material receiving vessel.
(2) The owner or operator of each capture system operated to comply
with paragraph (c)(1) of this section shall not discharge nor cause to
be discharged to the atmosphere from the capture system exhaust outlet
any gases that contain particulate matter greater than 16 mg/dscm as
determined by a performance test conducted in accordance with the
[[Page 19604]]
applicable requirements of Sec. 63.1451 of this subpart.
Sec. 63.1445 Standards: Slag cleaning vessels.
(a) The requirements of this section apply to affected existing and
new slag cleaning vessels at a primary copper smelter subject to this
subpart.
(b) The owner or operator shall discharge the off-gases exhausted
from the slag cleaning vessel in accordance with the requirements of
either paragraph (b)(1) or (b)(2) of this section.
(1) The owner or operator shall discharge the off-gases exhausted
from the slag cleaning vessel to a by-product sulfuric acid plant or
another type of sulfur recovery process that requires comparable levels
of gas stream pre-cleaning and conditioning to remove particulate
matter. A performance test is not required for gas streams that meet
the requirements of this paragraph.
(2) The owner or operator shall not discharge nor cause to be
discharged to the atmosphere from the slag cleaning vessel any off-
gases that contain particulate matter greater than 46 mg/dscm as
determined by a performance test conducted in accordance with the
applicable requirements of Sec. 63.1451 of this subpart.
(c) The owner or operator shall capture and control air emissions
when tapping molten material from the slag cleaning vessel in
accordance with the requirements of paragraphs (c)(1) and (c)(2) of
this section.
(1) The owner or operator shall install and operate a capture
system to collect gases and fumes released from each opening to the
slag cleaning vessel that is used to tap molten material from the
vessel. The design and placement of this capture system shall be such
that the tapping port opening, launder, and molten material receiving
vessel are positioned within the confines or influence of the system's
ventilation draft during all periods when molten material flows from
the tapping port into the molten material receiving vessel.
(2) The owner or operator of each capture system operated to comply
with paragraph (c)(1) of this section shall not discharge nor cause to
be discharged to the atmosphere from the capture system exhaust outlet
any gases that contain particulate matter greater than 16 mg/dscm as
determined by a performance test conducted in accordance with the
applicable requirements of Sec. 63.1451 of this subpart.
Sec. 63.1446 Standards: Copper converters.
(a) Applicability. The requirements of this section apply to the
affected copper converter department at a primary copper smelter
subject to this subpart. Standards for existing copper converter
departments are specified in paragraph (b) of this section. Standards
for new copper converter departments are specified in paragraph (c) of
this section.
(b) Standards for existing copper converter departments. The owner
or operator shall install, operate, and maintain air emission controls
for each copper converter located in the copper converter department.
As applicable to the copper converter design, the air emission controls
shall meet the requirements in either paragraphs (b)(1), (b)(2), or
(b)(3) of this section.
(1) Existing Pierce-Smith copper converters. Gases and fumes
emitted when the Pierce-Smith converter is operating in a blowing mode
shall be collected by a capture system and the captured gases and fumes
vented to a control device in accordance with the requirements of
paragraphs (b)(1)(i) through (b)(1)(iii) of this section.
(i) The capture system design shall include use of a primary hood
that covers the entire mouth of the copper converter when the copper
converter is positioned for blowing. Additional hoods (e.g., secondary
hoods) or other capture devices shall be included in the capture system
design as needed to achieve the operating requirements in paragraph
(b)(1)(ii) of this section. The capture system design may use multiple
intake and duct segments through which the ventilation rates are
controlled independently of each other and individual duct segments may
be connected to separate control devices.
(ii) The capture system shall be operated with sufficient
ventilation draft such that the visible emissions exiting the roof
monitors or roof exhaust fans on the building housing the copper
converter department do not exhibit an average opacity greater than 3
percent as determined by a performance test conducted in accordance
with the requirements of Sec. 63.1451(c) of this subpart. This visible
emission limit shall apply only during those periods when a performance
test is conducted in conjunction with establishing the capture system
operating parameter limits in accordance with the requirements in
Sec. 63.1452(c)(1) of this subpart. The requirements for compliance
with opacity and visible emission limits specified in Sec. 63.6(h) of
the general provisions in subpart A of this part do not apply to this
paragraph.
(iii) Each capture system exhaust stream shall be vented to one of
the air emission controls specified in paragraph (b)(1)(iii)(A) or
(b)(1)(iii)(B) of this section, as applicable considering the sulfur
oxide concentration of the individual gas stream.
(A) A by-product sulfuric acid plant or another type of sulfur
recovery process that requires comparable levels of gas stream pre-
cleaning and conditioning to remove particulate matter. A performance
test is not required for gas streams that meet the requirements of this
paragraph.
(B) A control device which does not exhaust any gases to the
atmosphere that contain particulate matter greater than 16 mg/dscm as
determined by a performance test conducted in accordance with the
applicable requirements of Sec. 63.1451 of this subpart.
(2) Existing Hoboken copper converters. Gases and fumes released
when the Hoboken converter is operating in a blowing mode shall be
evacuated directly from the interior of the copper converter into a
side flue intake positioned at one end of the converter vessel and
these captured gases and fumes vented to a control device in accordance
with the requirements of paragraphs (b)(2)(i) and (b)(2)(ii) of this
section.
(i) The side flue intake of each Hoboken copper converter shall be
operated with sufficient ventilation draft during blowing such that the
visible emissions exiting the roof monitors on the building housing the
copper converter department do not exhibit an average opacity greater
than 4 percent as determined by performance tests conducted in
accordance with the requirements of Sec. 63.1451(c) of this subpart.
This visible emission limit shall apply only during those periods when
a performance test is conducted in conjunction with establishing the
capture system operating parameter limits in accordance with the
requirements in Sec. 63.1452(c)(1) of this subpart. The requirements
for compliance with opacity and visible emission limits specified in
Sec. 63.6(h) of the general provisions in subpart A of this part do not
apply to this paragraph.
(ii) Each side flue exhaust stream shall be vented through a
capture system to a by-product sulfuric acid plant or another type of
sulfur recovery process that requires comparable levels of gas stream
pre-cleaning and conditioning to remove particulate matter. A
performance test is not required for gas streams that meet the
requirements of this paragraph.
(3) Other existing batch copper converters. Gases and fumes
released from a batch copper converter that is neither a Pierce-Smith
copper converter nor a Hoboken copper converter shall be
[[Page 19605]]
controlled in accordance with the requirements in paragraphs (b)(1)(i)
through (b)(1)(iii) of this section.
(c) Standards for new copper converter departments. The owner or
operator shall install, operate, and maintain air emission controls for
each copper converter located in the copper converter department. The
air emission controls shall meet the requirements in paragraphs (c)(1)
through (c)(3) of this section.
(1) Gases and fumes emitted whenever molten material is in the
copper converter shall be collected by a capture system, and the
captured gases and fumes shall be vented to a control device. The
capture system design may use multiple intake and duct segments through
which the ventilation rates are controlled independently of each other,
and individual duct segments may be connected to separate control
devices. (e.g., use of individual hoods on each copper converter in
combination with a building evacuation system).
(2) The capture system shall be operated with sufficient
ventilation draft whenever molten material is in the copper converter
such that no visible emissions exit the the building housing the copper
converter department as determined by performance tests conducted in
accordance with the requirements of Sec. 63.1451(d) of this subpart.
(3) Each capture system exhaust stream shall be vented to one of
the air emission controls specified in paragraphs (c)(3)(i) or
(c)(3)(ii) of this section, as applicable considering the sulfur oxide
concentration of the individual gas stream.
(i) A by-product sulfuric acid plant or a another type of sulfur
recovery process that requires comparable levels of gas stream pre-
cleaning and conditioning to remove particulate matter. A performance
test is not required for gas streams that meet the requirements of this
paragraph.
(ii) A control device which does not exhaust any gases to the
atmosphere that contain particulate matter greater than 16 mg/dscm as
determined by a performance test conducted in accordance with the
applicable requirements of Sec. 63.1451 of this subpart.
Sec. 63.1447 [Reserved].
Sec. 63.1448 Standards: Fugitive dust sources.
(a) The requirements of this section apply to existing and new
affected sources of fugitive dust emissions at a primary copper smelter
subject to this subpart.
(b) The owner or operator shall prepare and implement a written
fugitive dust control plan in accordance with the requirements
specified in paragraphs (b)(1) through (b)(3) of this section.
(1) The fugitive dust control plan shall describe the specific
control measures that are used to reduce emissions from the individual
fugitive dust sources at the smelter site. Examples of control measures
that may be used include, but are not limited to: installing an
enclosure, installing and operating a local hood capture system vented
to a control device, placing stockpiles below grade, installing wind
screens or wind fences, using water sprays, applying appropriate dust
suppression agents, or any combination of these control measures as
appropriate for a given fugitive dust source.
(2) The fugitive dust control plan shall include a description of
the control measures implemented for each of the fugitive dust sources
listed in paragraphs (b)(2)(i) through (b)(2)(vi) of this section.
(i) Roads or other areas within the plant property boundary used by
trucks or other motor vehicles (e.g., front-end loaders) transporting
bulk quantities of fugitive dust materials. Paved roads and areas of
the smelter site that are not used by these vehicles are not required
to be included in the plan (e.g., employee and visitor parking lots);
(ii) Operations to unload fugitive dust materials from trucks or
railcars;
(iii) Outdoor piles used to store fugitive dust materials;
(iv) Bedding areas used for blending copper concentrate and other
feed constituents;
(v) Transfer points in conveying systems used to convey fugitive
dust materials. These points include, but are not limited to, those
points where the material is transferred from a conveyor belt to a
second conveyor belt or discharged from a conveyor to a hopper or bin;
and
(vi) Other fugitive dust sources at a smelter site as designated by
the Administrator or delegated permitting authority.
(3) The owner or operator shall submit a copy of the fugitive dust
control plan to the designated permitting authority on or before the
applicable compliance date for the affected source as specified in
Sec. 63.1450(b) of this subpart. The requirement for the owner or
operator to operate the smelter according to a written fugitive dust
control plan shall be incorporated in the operating permit for the
smelter site that is issued by the designated permitting authority
under part 70 of this chapter.
Sec. 63.1449 Equivalent standard: combined exhaust gas streams.
(a) As an alternative to complying with the individual particulate
matter emission limits specified in this subpart for affected sources,
an owner or operator may elect to combine two or more of the affected
exhaust gas streams listed in paragraphs (a)(1) through (a)(4) of this
section and route the combined exhaust gas stream to a single control
device that meets the equivalent particulate emission limit specified
in paragraph (b) of this section.
(1) Exhaust gas stream from a copper concentrate dryer that would
otherwise be subject to Sec. 63.1443 of this subpart;
(2) Exhaust gas stream from a smelting vessel capture system that
would otherwise be subject to Sec. 63.1444(c)(2) of this subpart;
(3) Exhaust gas stream from a slag cleaning vessel capture system
that would otherwise be subject to Sec. 63.1445(c)(2) of this subpart;
and
(4) Exhaust gas stream from a copper converter capture system that
would otherwise be subject to Secs. 63.1446(b)(1)(iii)(B) or (c)(3)(ii)
of this subpart.
(b) An owner or operator shall not discharge nor cause to be
discharged to the atmosphere a combined exhaust gas stream that
contains particulate matter greater than the particulate matter
emission limit calculated for the combined exhaust gas stream using the
procedure specified in paragraphs (b)(1) and (b)(2) of this section.
Particulate matter emissions in the combined exhaust gas stream shall
be determined by a performance test conducted in accordance with the
applicable requirements of Sec. 63.1451 of this subpart.
(1) The particulate matter emission limit for the combined exhaust
gas stream shall be calculated using Equation 1:
[[Page 19606]]
[GRAPHIC] [TIFF OMITTED] TP20AP98.000
Where:
E=Particulate matter emission limit for the combined exhaust gas stream
(mg/dscm);
Ed=Particulate matter emission limit applicable to copper
concentrate dryer as specified in Sec. 63.1443 of this subpart (mg/
dscm);
Qd=Copper concentrate dryer exhaust gas stream volumetric
flow rate as determined by the procedure specified in paragraph (b)(2)
of this section (dscm);
Esv=Particulate matter emission limit for smelting vessel
capture system as specified in Sec. 63.1444(c)(2) of this subpart (mg/
dscm);
Qsv= Smelting vessel capture system exhaust gas stream
volumetric flow rate as determined by the procedure in paragraph (b)(2)
of this section (dscm);
Escv=Particulate matter emission limit for slag cleaning
vessel capture system as specified in Sec. 63.1445(c)(2) of this
subpart (mg/dscm).
Qscv=Slag cleaning vessel capture system exhaust gas stream
volumetric flow rate as determined by the procedure specified in
paragraph (b)(2) of this section (dscm);
Ecc=Particulate emission limit for copper converter capture
system as specified in Sec. 63.1446(b)(1)(iii)(B) or
Sec. 63.1446(c)(iii) of this subpart as applicable to the copper
converter department (mg/dscm); and
Qcc=Copper converter capture system exhaust gas stream
volumetric flow rate as determined by the procedure specified in
paragraph (b)(2) of this section (dscm).
(2) The volumetric flow rate of each individual exhaust gas stream
used for the calculation specified in paragraph (b)(1) of this section
shall be the average of the volumetric flow rates measured during each
performance test run performed in accordance with the requirements of
Sec. 63.1451(b) of this subpart and used to determine compliance with
the applicable particulate matter emission limits specified in
Secs. 63.1443 through 63.1446 of this subpart.
Sec. 63.1450 Compliance with standards and maintenance requirements.
(a) General. The requirements of this section apply to an owner or
operator of an affected source required to comply with applicable
standards under this subpart.
(b) Compliance dates. (1) The owner or operator of an affected
source for which construction or reconstruction commences on or after
April 20, 1998 shall achieve compliance with the applicable
requirements of this subpart upon initial startup or [date of
publication of the final rule in the Federal Register], whichever date
is later.
(2) The owner or operator of an affected source that commenced
construction or reconstruction before April 20, 1998 shall achieve
compliance with the applicable requirements of this subpart as
expeditiously as practical, but no later than [date 2 years after date
of publication of final rule in the Federal Register].
(c) Operation and maintenance requirements. (1) At all times,
including periods of startup, shutdown, and malfunction, the owner or
operator shall operate and maintain each affected source, including
associated air pollution control equipment, in accordance with the
requirements of Sec. 63.6 of the general provisions in subpart A of
this part.
(2) The owner or operator shall develop and implement a written
startup, shutdown, and malfunction plan in accordance with the
requirements to Sec. 63.6(e)(3) of the general provisions in subpart A
of this part that describes the specific procedures to be followed for
operating and maintaining each affected source and its associated air
pollution control equipment during periods of startup, shutdown, and
malfunction. In addition to the information required in Sec. 63.6(e)(3)
of this part, the information specified in paragraphs (c)(2)(i) through
(c)(2)(iii) of this section shall be included in each plan.
(i) For the copper converter department capture system required by
Sec. 63.1446 of this subpart, a description of the corrective actions
to be implemented by the owner or operator in the event that the
operating parameter monitoring system measures a value for an operating
parameter that exceeds the limit established for the parameter under
Sec. 63.1452(c)(1) of this subpart.
(ii) For each baghouse that is used to comply with a particulate
matter emission limit under Secs. 63.1442 through 63.1446 of this
subpart, a standard operating procedures (SOP) manual that specifies,
in detail, the procedures to be used by the owner or operator for
inspection, maintenance, bag leak detection, and corrective action. The
procedures specified in the SOP manual for inspections and routine
maintenance of the baghouse shall, at a minimum, include the
requirements in Sec. 63.1452(d) of this subpart. The requirements of
this paragraph do not apply to a baghouse used exclusively for the
control of fugitive dust emissions in accordance with the requirements
under Sec. 63.1448 of this subpart.
(iii) For each control device other than a baghouse that is used to
comply with a particulate matter emission limit under Secs. 63.1442
through 63.1446 of this subpart, a description of the corrective
actions to be implemented by the owner or operator in the event that
the operating parameter monitoring system measures a value for an
operating parameter that exceeds the limit established for the
parameter under Sec. 63.1452(e)(1) of this subpart.
Sec. 63.1451 Performance testing requirements.
(a) General. The requirements of this section apply to an owner or
operator required to conduct performance tests to demonstrate
compliance by an affected source with applicable emission limits under
Secs. 63.1442 through 63.1446 of this subpart.
(b) Conduct of particulate matter emission limit performance tests.
The owner or operator shall conduct each performance test required
under this subpart to determine compliance with the applicable
particulate matter emission limits specified in Secs. 63.1443 through
63.1446 of this subpart in accordance with applicable requirements in
Sec. 63.7 of the general provisions in subpart A of this part and shall
use reference methods specified in paragraphs (b)(1) through (b)(5) of
this section.
(1) Method 1 in appendix A of part 60 of this chapter shall be used
to select the sampling port location and the number or traverse points;
(2) Method 2 in appendix A of part 60 of this chapter shall be used
to measure the volumetric flow rate;
(3) Method 3 in appendix A of part 60 of this chapter shall be used
for gas analysis;
(4) Method 4 in appendix A of part 60 of this chapter shall be used
to determine stack gas moisture; and
(5) Method 5 in appendix A to part 60 of this chapter shall be used
for measurement of particulate matter
[[Page 19607]]
emissions from sources other than positive pressure baghouses. Method
5D in appendix A of part 60 of this chapter shall be used for
measurement of particulate matter emissions from positive pressure
baghouses. The minimum sampling time for each run shall be 60 minutes
and the minimum sampling volume for the run shall be 0.85 dscm. Three
runs shall be performed and the average of the three runs shall be used
to determine compliance.
(c) Conduct of existing copper converter department visible
emissions performance tests. The owner or operator shall determine
compliance of an existing copper converter department with the
applicable visible emission limit specified in Sec. 63.1446(b) of this
subpart by using the procedure specified in paragraphs (c)(1) through
(c)(7) of this section.
(1) Test conditions. The opacity observations shall be made during
the period when the primary copper smelter is operating under
conditions representative of the smelter's normal blister copper
production rate. Before conducting the opacity observations, the owner
or operator shall prepare a written test plan specifying the copper
production conditions to be maintained throughout the opacity
observation period. A copy of the test plan shall be submitted for
review and approval by the Administrator or delegated authority. During
the observation period, the owner or operator shall collect appropriate
process information to prepare sufficient documentation to verify that
all opacity observations were made during the conditions specified in
the approved test plan.
(2) Test notification. The owner or operator shall notify the
Administrator or delegated authority before conducting the opacity
observations to allow the Administrator or delegated authority the
opportunity to have authorized representatives attend the test. Written
notification of the location and scheduled date for conducting the
opacity observations shall be received by the Administrator on or
before 30 calendar days before this scheduled date.
(3) Opacity observation period. The total time that opacity
observations are made shall be of sufficient duration to obtain a
minimum of 20 uninterrupted 6-minute intervals during which opacity
readings in accordance with Method 9 in appendix A of part 60 of this
chapter (i.e., 24 opacity readings, each reading made at a 15-second
interval) are recorded for those conditions when at least one copper
converter is operating in the blowing mode and no interferences occur
as specified in paragraph (c)(6) of this section. The total observation
period may be divided into two or more segments performed on different
days if changes in outdoor conditions (e.g., position of sun relative
to observers does meet the Method 9 criteria) or copper production
conditions (e.g., equipment malfunction or process upset) prevent the
required number of opacity readings from being obtained during one
continuous period. If the total observation period is divided into two
or more segments, all opacity observations shall be made during the
same set of copper production conditions specified in the approved test
plan.
(4) Conduct of opacity observations. All opacity observations shall
be made using Method 9 in appendix A to part 60 of this chapter and the
procedures specified in paragraphs (c)(4)(i) through (c)(4)(iv) of this
section.
(i) The opacity observations shall be performed by a team of
qualified visible emission observers. A sufficient number of observers
shall be used to obtain two complete concurrent sets of 24 opacity
readings for each of the required 6-minute observation intervals. All
concurrent sets of 24 opacity readings need not be made by the same two
observers; observer substitutions are allowed to provide observer rest
breaks.
(ii) Each visible emission observer shall be certified as a
qualified observer by the procedure specified in section 3 of Method 9
in appendix A of part 60 of this chapter. The owner or operator shall
obtain proof of current visible emission reading certification for each
observer.
(iii) Before beginning the opacity readings, all of the outdoor
opacity observers shall identify and designate using a common
identification code (e.g., consecutive numbers, alphabetic letters)
each of the copper converter department visible emission points on the
building for which opacity readings are to be made. The copper
converter department visible emission points are those sections of the
building roof monitor or those roof exhaust fan outlets that are
positioned over the location of the copper converters inside the
building.
(iv) Each observer shall take a position that meets the criteria
specified in section 2.1 of Method 9 in appendix A of part 60 of this
chapter and provides the observer with an unobstructed view of the
designated converter department visible emission points. For each
opacity reading, the observer shall record the identification code for
the converter department visible emission point for which the reading
was made. When during an individual opacity reading it is possible for
an observer to distinguish two or more visible emission plumes from the
designated converter department visible emission points, the observer
shall identify, to the extent feasible, the plume having the highest
opacity and record his or her opacity reading for that plume.
(5) Process information gathering. Throughout the opacity
observation period, one or more persons familiar with the primary
copper smelter operations shall be stationed inside the building
housing the copper converters to visually monitor the copper converter
operations. Each indoor process monitor shall record all observations
in an operating log using the procedure specified in paragraphs
(c)(5)(i) and (c)(5)(ii) of this section.
(i) Before beginning the opacity readings, the actions specified in
paragraphs (c)(5)(i)(A) and (c)(5)(i)(B) of this section.
(A) An identification code (e.g., a number, a letter) shall be
assigned to each copper converter in the copper converter department;
and
(B) The clock time setting on the watch or clock to be used by the
indoor process monitor shall be synchronized with the clock times
settings for the timepieces to be used by the outdoor opacity
observers.
(ii) During all periods when opacity readings are being made by the
outdoor opacity observers, the indoor process monitor shall record in
the operating log the information specified in paragraphs (c)(5)(ii)(A)
and (c)(5)(ii)(B) of this section.
(A) When a copper converter is positioned in the blowing mode, the
operating log entry for each activity shall include, but is not limited
to, the following information:
(1) The copper converter identification code;
(2) The clock times for when blowing begins and when blowing ends;
and
(3) The converter blowing rate. This information may be recorded by
a separate computer data system.
(B) When an activity related to operating the copper converters or
occurring in a converter aisle is observed by an indoor process monitor
to generate visible emissions inside the building housing the copper
converters, the operating log entry for each activity shall include,
but is not limited to, the following information:
(1) A description of the activity;
(2) The clock times when the activity begins and when the activity
ends; and
(3) If the activity pertains to a specific copper converter, the
copper converter identification code.
[[Page 19608]]
(6) Data reduction. Using the information recorded in opacity field
data sheets prepared by the outdoor opacity observers and the indoor
process operating logs prepared by the indoor process monitor, data
summary sheets for the entire observation period shall be prepared
using the procedure specified in paragraphs (c)(6)(i) and (c)(6)(ii) of
this section.
(i) Prepare data summary sheets for the entire observation period
that lists by the clock time at 1-minute intervals the average of the
opacity values read by the two observers during each 1-minute interval.
[see Figure 1 of this subpart for an example of the format to use for
the data summary sheets.] The average opacity value to be recorded on
the data summary sheet for each 1-minute interval shall be calculated
as an average of the eight 15-second interval readings recorded on the
field data sheets by the two observers during a given clock time minute
interval (add the four consecutive 15-second interval opacity readings
made by Observer A during the specified clock time minute plus the four
consecutive 15-second interval opacity readings made by Observer B
during the same clock time minute, and divide this resulting total by
eight).
(ii) Using the complete set of data summary sheets prepared in
accordance with paragraph (c)(6)(i) of this section, identify on each
data summary sheet those 1-minute intervals when one or more converters
are operating in the blowing mode and no interferences occur. An
``interference'' is a period composed of consecutive clock time minutes
during which one or more of the interference activities listed in
paragraph (c)(6)(ii)(A) of this section occurs plus an appropriate time
delay factor to account for the time lag between when the visible
emissions generated by this activity are seen by the indoor process
monitor and when these emissions impact the opacity recorded by the
outdoor opacity observers. The time delay factor shall be determined on
a site-specific basis as specified in paragraph (c)(6)(ii)(B) of this
section.
(A) Interference activities. For the purpose of identifying
``interferences'', only the activities listed in paragraphs
(c)(6)(ii)(A)(1) through (c)(6)(ii)(A)(6) of this section are
considered to be interference activities. Other ancillary activities
that are conducted in or adjacent to the copper converter aisle during
the opacity observations that could potentially cause higher opacity
readings from the designated converter department visible emission
points are not considered to be interference activities (e.g.,
converter aisle cleaning, placement of smoking ladles or skulls on the
copper converter aisle floor). The following activities are
interference activities:
(1) Charging of copper matte, reverts, or other materials to a
copper converter;
(2) Skimming slag or other molten materials from a copper
converter;
(3) Pouring of blister copper or other molten materials from a
copper converter;
(4) Return of slag or other molten materials to the flash smelting
furnace or slag cleaning vessel;
(5) Roll-out or roll-in of the copper converter; or
(6) Presence of smoke or fumes generated in the smelting vessel,
slag cleaning vessel, or anode refining areas that drifts into the
copper converter department.
(B) Time delay factor. The interference period may be extended
beyond the clock time recorded for cessation of the interference
activity by adding a time delay factor. This time delay factor shall be
a constant number of minutes not to exceed 5 minutes that is added to
the clock time recorded when cessation of the interference activity
occurs. The number of minutes to be used for the time delay factor
shall be determined based on the information in the data file. An
explanation of the rationale for selecting the value used for the time
delay factor shall be prepared and included in the test report.
(7) Calculation of average opacity for determination of compliance
with opacity standard. Compliance shall be determined using only those
opacity readings listed in the complete set of data summary sheets
prepared in accordance with paragraph (c)(6) of this section that are
identified as occurring during a period when one or more converters are
operating in the blowing mode with no interferences.
(i) Beginning at the first clock minute listed on the data summary
sheets prepared in accordance with paragraph (c)(6) of this section,
calculate 6-minute average opacity values for those periods composed of
six consecutive minutes of blowing with no interferences. A minimum of
20 6-minute periods is required for the compliance calculation. If more
than twenty 6-minute periods are included in the set of data summary
sheets, then all of the 6-minute periods included in the set of data
summary sheets shall be used for the compliance calculation.
(ii) Average opacity shall be calculated using Equation 2:
[GRAPHIC] [TIFF OMITTED] TP20AP98.001
where
VEave=Average opacity to be used for compliance
determination (percent);
n=Number of 6-minute opacity averages in the data set (at least 20);
i=Period ``i'' composed of 6 consecutive minutes with at least one
converter blowing and no interferences; and
VEi=6-minute average opacity calculated for period ``i''
(percent).
(d) Conduct of new copper converter department visible emission
performance tests. The owner or operator shall determine compliance
with the visible emission limit for new copper converter departments
specified in Sec. 63.1446(c) of this subpart by using the procedure
specified in paragraphs (d)(1) through (d)(3) of this section.
(1) Test conditions. The test shall be made during the period when
the primary copper smelter is operating under conditions representative
of the smelter's normal blister copper production rate. Before
conducting the opacity observations, the owner or operator shall
prepare a written test plan specifying the copper production conditions
to be maintained throughout the visible emission observation period. A
copy of the test plan shall be submitted for review and approval by the
Administrator or delegated authority. During the observation period,
the owner or operator shall collect appropriate process information to
prepare sufficient documentation to verify that all visible emission
observations were made during the conditions specified in the approved
test plan.
(2) Test notification. The owner or operator shall notify the
Administrator or delegated authority before conducting the test to
allow the Administrator or delegated authority the opportunity to have
authorized representatives attend the test. Written notification of the
location and scheduled date for conducting the visible emission
observations shall be received by the Administrator on or before 30
calendar days before this scheduled date.
(3) Test procedure. The visible emissions from the building housing
the copper converter department shall be determined using Method 22 in
appendix A of part 60 of this chapter, with an observation period of no
less than 2 hours.
Sec. 63.1452 Inspection and monitoring requirements.
(a) General. The requirements of this section apply to an owner or
operator of an affected source required to install and operate air
emission control equipment in accordance with
[[Page 19609]]
applicable standards under Secs. 63.1442 through 63.1446 of this
subpart.
(b) Capture system inspection requirements. The owner or operator
shall inspect each capture system operated to meet applicable standards
under Sec. 63.1044 through Sec. 63.1046 of this subpart in accordance
with the requirements in paragraphs (b)(1) through (b)(4) of this
section.
(1) Each inspection shall include visually checking all of the
capture system components to detect any defects or damage that could
diminish or impair capture system performance from the level that the
capture system achieves when it is properly operated and maintained.
Examples of such defects or damage include, but are not limited to,
openings through which gases can escape as indicated by the presence of
cracks, holes, or gaps in hoods or ductwork; flow constrictions caused
by dents or accumulated dust in ductwork; and reduced fan performance
as indicated by fan blade erosion.
(2) An inspection of each capture system shall be conducted at
least once every month.
(3) In the event a defect or damaged component is detected, the
owner or operator shall replace or repair the component consistent with
the corrective action procedures identified in the startup, shutdown,
and malfunction plan. The owner or operator shall complete the repair
as soon as practicable but no later than 30 calendar days after the
date of detection except under the special circumstances described in
paragraph (b)(4) of this section.
(4) Delay of repair of a capture system defect beyond 30 calendar
days is allowed when the repair cannot be completed within the 30-day
period because of factors beyond the direct control of the owner or
operator (e.g., time required to obtain a critical replacement part
from the manufacturer). In this case, the repair shall be completed as
soon as practicable, consistent with the corrective action procedures
identified in the startup, shutdown, and malfunction plan. For each
repair delay, the owner or operator shall maintain a record describing
the work required to complete the repair, the reason for the repair
delay, and the date that completion of the repair is planned.
(c) Copper converter department capture system monitoring
requirements. The owner or operator shall ensure that each copper
converter department capture system required under Sec. 63.1446 of this
subpart is properly operated and maintained by monitoring the operation
of the capture system as required in paragraphs (c)(1) through (c)(5)
of this section.
(1) During each performance test conducted to demonstrate
compliance with a visible emission limit under Sec. 63.1446 of this
subpart, a range of operating values shall be established for the
copper converter department capture system that is a representative and
reliable indicator that the capture system is being properly operated
and maintained (i.e., operating within the same range of conditions
used to demonstrate compliance of the capture system with the
applicable visible emission limit specified in Sec. 63.1446 of this
subpart). This range of operating values shall be established for the
capture system using the procedure in paragraphs (c)(1)(i) through
(c)(1)(iv) of this section.
(i) The owner or operator shall select a set of operating
parameters appropriate for the capture system design that the owner or
operator determines to be a representative and reliable indicator of
the capture system performance. Appropriate capture system operating
parameter sets include, but are not limited to:
(A) Capture system fan motor amperes with all duct damper position
settings; or
(B) Volumetric flow rate through each separately ducted hood.
(ii) The owner or operator shall measure and record each of the
selected operating parameters during all visible emission observations
conducted for the capture system performance test. At a minimum, a
value for each selected parameter shall be recorded at least once every
15 minutes.
(iii) For each selected operating parameter monitored in accordance
with the requirements of paragraph (c)(1)(ii) of this section, the
owner or operator shall establish a minimum operating parameter limit
or a maximum operating parameter limit, as appropriate for the
parameter, to define the operating limits within which the capture
system can operate and still continuously achieve the same operating
conditions used to demonstrate compliance of the capture system with
the applicable visible emission limit specified in Sec. 63.1446 of this
subpart.
(iv) The owner or operator shall prepare written documentation to
support the operating parameter limits established for the capture
system. This documentation shall include a description for each
selected parameter and the operating range and monitoring frequency
required to ensure the capture system is being properly operated and
maintained.
(2) The owner or operator shall monitor the selected operating
parameters in accordance with the requirements of either paragraph
(c)(2)(i) or (c)(2)(ii) of this section, as applicable.
(i) Except in those cases when the owner or operator elects to
monitor the operating parameter set specified in paragraph (c)(1)(i)(A)
of this section, the owner or operator shall install, calibrate,
operate, and maintain a device equipped with a recorder to measure the
values for each operating parameter selected in accordance with the
requirements of paragraph (c)(1) of this section. The monitoring
equipment shall be installed, calibrated, and maintained in accordance
with the equipment manufacturer's specifications. The recorder shall be
a data recording device that either records an instantaneous data value
for the operating parameter at least once every 15 minutes or records
15-minute or more frequent block average values.
(ii) In those cases when the owner or operator elects to monitor
the operating parameter set specified in paragraph (c)(1)(i)(A) of this
section, the owner or operator shall develop and implement a written
procedure for the converter operator or other appropriate worker to
check at least once per shift that fan amperage and damper positions
are within the operating parameter limits established for the capture
system.
(3) The owner or operator shall regularly inspect the data recorded
by the operating parameter monitoring system at a sufficient frequency
to ensure the capture system is operating properly. An excursion is
determined to have occurred any time that the actual value of a
selected operating parameter is less than the minimum operating limit
(or, if applicable, greater than the maximum operating limit)
established for the parameter in accordance with the requirements of
paragraph (c)(1) of this section.
(4) Whenever an excursion occurs, the owner or operator shall
initiate within one hour of detecting the excursion the corrective
action procedures identified in the startup, shutdown, and malfunction
plan as necessary to restore the operation of the capture system to the
proper operating settings. Failure to initiate the corrective action
procedures within one hour of detecting an excursion or to take the
necessary corrective actions to remedy the problem is a violation of
the standard in this subpart.
(5) For a given operating parameter, if an excursion occurs six or
more times in any semi-annual reporting period, then any subsequent
excursion of that
[[Page 19610]]
operating parameter during the reporting period is a violation of the
standard in this subpart. For the purpose of determining the number of
excursions in a semi-annual reporting period, only one excursion shall
be counted in any given 24-hour period.
(d) Baghouse inspection and monitoring requirements.
(1) The owner or operator shall prepare and at all times operate
according to a standard operating procedures (SOP) manual for
inspection, maintenance, and bag leak detection, and corrective action
plans for each baghouse used to comply with applicable standards under
Secs. 63.1442 through 63.1446 of this subpart. The requirements of this
paragraph do not apply to a baghouse that is operated exclusively to
control fugitive dust emissions.
(2) The procedures specified in the SOP manual for inspections and
routine maintenance of a baghouse shall, at a minimum, include the
requirements of paragraphs (d)(2)(i) through (d)(2)(ix) of this
section.
(i) Daily monitoring of pressure drop across each baghouse cell;
(ii) Weekly confirmation that dust is being removed from hoppers
through visual inspection, or equivalent means of ensuring the proper
functioning of removal mechanisms;
(iii) Daily check of compressed air supply for pulse-jet baghouses;
(iv) An appropriate methodology for monitoring cleaning cycles to
ensure proper operation;
(v) Monthly check of bag cleaning mechanisms for proper functioning
through visual inspection or equivalent means;
(vi) Quarterly check of bag tension on reverse air and shaker-type
baghouses. Such checks are not required for shaker-type baghouses using
self-tensioning (spring loaded) devices;
(vii) Quarterly confirmation of the physical integrity of the
baghouse through visual inspection of the baghouse interior for air
leaks;
(viii) Quarterly inspection of fans for wear, material buildup, and
corrosion through visual inspection, vibration detectors, or equivalent
means; and
(ix) Continuous operation of a bag leak detection system.
(3) The procedures for maintenance specified in the SOP manual
shall, at a minimum, include a preventative maintenance schedule that
is consistent with the baghouse manufacturer's instructions for routine
and long-term maintenance.
(4) The bag leak detection system required by paragraph (d)(1) of
this section, shall meet the specifications and requirements of
paragraphs (d)(3)(i) through (d)(3)(viii) of this section.
(i) The bag leak detection system must be certified by the
manufacturer to be capable of detecting particulate matter emissions at
concentrations of 10 mg/acfm or less;
(ii) The bag leak detection system sensor must provide output of
relative particulate matter loadings;
(iii) The bag leak detection system must be equipped with an alarm
system that will sound an audible alarm when an increase in relative
particulate loadings is detected over a preset level;
(iv) The bag leak detection system shall be installed and operated
in a manner consistent with available written guidance from the U.S.
Environmental Protection Agency or, in the absence of such written
guidance, the manufacturer's written specifications and recommendations
for installation, operation, and adjustment of the system;
(v) The initial adjustment of the system shall, at a minimum,
consist of establishing the baseline output by adjusting the
sensitivity (range) and the averaging period of the device, and
establishing the alarm set points and the alarm delay time;
(vi) Following initial adjustment, the owner or operator shall not
adjust the sensitivity or range, averaging period, alarm set points, or
alarm delay time, except as detailed in the SOP manual required under
paragraph (d)(1) of this section. In no event shall the sensitivity be
increased by more than 100 percent or decreased more than 50 percent
over a 365 day period unless such adjustment follows a complete
baghouse inspection which demonstrates the baghouse is in good
operating condition;
(vii) For negative pressure or induced air baghouses, and positive
pressure baghouses that are discharged to the atmosphere through a
stack, the bag leak detector must be installed downstream of the
baghouse and upstream of any wet acid gas scrubber; and
(viii) Where multiple detectors are required, the system's
instrumentation and alarm system may be shared among the detectors.
(5) The SOP manual required by paragraph (d)(1) of this section
shall include a corrective action plan that specifies the procedures to
be followed in the case of a bag leak detection system alarm. The
corrective action plan shall include, at a minimum, the procedures used
to determine and record the time and cause of the alarm as well as the
corrective actions taken to correct the control device malfunction or
minimize emissions as specified in paragraphs (d)(4)(i) and (d)(4)(ii)
of this section. Failure to initiate the corrective action required by
this paragraph is a violation of the standard in this subpart.
(i) The procedures used to determine the cause of the alarm must be
initiated within 30 minutes of the time the alarm first sounds; and
(ii) The cause of the alarm must be alleviated by taking the
necessary corrective action(s) which may include, but are not to be
limited to, the actions in paragraphs (d)(5)(ii)(A) through
(d)(5)(ii)(F) of this section.
(A) Inspecting the baghouse for air leaks, torn or broken filter
elements, or any other malfunction that may cause an increase in
emissions;
(B) Sealing off defective bags or filter media;
(C) Replacing defective bags or filter media, or otherwise
repairing the control device;
(D) Sealing off a defective baghouse compartment;
(E) Cleaning the bag leak detection system probe, or otherwise
repairing the bag leak detection system; or
(F) Shutting down the process producing the particulate emissions.
(e) Monitoring of venturi wet scrubbers. For each venturi wet
scrubber operated to comply with applicable particulate matter emission
limits in Secs. 63.1442 through 63.1446 of this subpart, the owner or
operator shall ensure that the venturi wet scrubber is properly
operated and maintained by monitoring the operation of the wet control
device as required in paragraphs (e)(1) through (e)(3) of this section.
(1) During each performance test conducted to demonstrate
compliance of a venturi wet scrubber outlet gas stream with the
applicable particulate matter emission limit, minimum operating values
shall be established for the scrubber pressure drop and the scrubber
water flow rate. These operating values shall be established for the
venturi wet scrubber using the procedure in paragraphs (e)(1)(i)
through (e)(1)(iii) of this section.
(i) The owner or operator shall measure and record values for the
scrubber pressure drop and scrubber water flow rate during each test
run conducted for a performance test to demonstrate compliance with the
applicable standard. At a minimum, a value for each operating parameter
shall be recorded at least once every 15 minutes during the test run.
(ii) For each operating parameter measured in accordance with the
requirements of paragraphs (e)(1)(i) of this section, the owner or
operator shall establish an operating parameter limit to define the
minimum scrubber pressure drop and minimum scrubber water flow
[[Page 19611]]
rate at which the scrubber can operate and still continuously achieve
the applicable particulate matter emission limit.
(iii) The owner or operator shall prepare written documentation to
support the minimum operating parameter limits established for the
scrubber.
(2) The owner or operator shall install, calibrate, operate, and
maintain monitoring devices equipped with a recorder to measure the
values for scrubber pressure drop and scrubber water flow rate. The
monitoring equipment shall be installed, calibrated, and maintained in
accordance with the equipment manufacturer's specifications. The
recorder shall be a data recording device that either records an
instantaneous data value for the operating parameter at least once
every 15 minutes or records 15-minute or more frequent block average
values.
(3) The owner or operator shall regularly inspect the data recorded
by the operating parameter monitoring system at a sufficient frequency
to ensure the scrubber is operating properly. An excursion is
determined to have occurred any time that the actual value of the
scrubber pressure drop or water flow rate is less than the minimum
limit established for the parameter in accordance with the requirements
of paragraph (e)(1) of this section. Any excursion recorded for the
venturi wet scrubber shall be a violation of the standard in this
subpart.
(f) Monitoring of control devices other than baghouses or venturi
wet scrubbers. For each control device that is not a baghouse or
venturi wet scrubber but is operated to comply with applicable
particulate matter emission limits in Secs. 63.1442 through 63.1446 of
this subpart, the owner or operator shall ensure that the control
device is properly operated and maintained by monitoring the operation
of the control device as required in paragraphs (f)(1) through (f)(4)
of this section.
(1) During each performance test conducted to demonstrate
compliance of a control device outlet gas stream with the applicable
particulate matter emission limit, a range of operating values shall be
established for the control device that is a representative and
reliable indicator that the control device is operating within the same
range of conditions used to demonstrate compliance of the control
device with the applicable particulate matter emission limit. This
range of operating values shall be established for the control device
using the procedure in paragraphs (f)(1)(i) through (f)(1)(iv) of this
section.
(i) The owner or operator shall select a set of operating
parameters appropriate for the control device design that the owner or
operator determines to be a representative and reliable indicator of
the control device performance.
(ii) The owner or operator shall measure and record values for each
of the selected operating parameters during each test run conducted for
the performance test to demonstrate compliance with the applicable
standard. At a minimum, a value for each selected parameter shall be
recorded at least once every 15 minutes.
(iii) For each selected operating parameter measured in accordance
with the requirements of paragraphs (f)(1)(ii) of this section, the
owner or operator shall establish a minimum operating parameter limit
or a maximum operating parameter limit, as appropriate for the
parameter, to define the operating limits within which the control
device can operate and still continuously achieve the same operating
conditions used to demonstrate compliance of the control device with
the applicable particulate matter emission limit.
(iv) The owner or operator shall prepare written documentation to
support the operating parameter limits established for the control
device. This documentation shall include a description for each
selected parameter and the operating range and monitoring frequency
required to ensure the control device is being properly operated and
maintained.
(2) The owner or operator shall install, calibrate, operate, and
maintain a monitoring device equipped with a recorder to measure the
values for each operating parameter selected in accordance with the
requirements of paragraph (f)(1) of this section. The monitoring
equipment shall be installed, calibrated, and maintained in accordance
with the equipment manufacturer's specifications. The recorder shall be
a data recording device that either records an instantaneous data value
for the operating parameter at least once every 15 minutes or records
15-minute or more frequent block average values.
(3) The owner or operator shall regularly inspect the data recorded
by the operating parameter monitoring system at a sufficient frequency
to ensure the control device is operating properly. An excursion is
determined to have occurred any time that the actual value of a
selected operating parameter is less than the minimum operating limit
(or, if applicable, greater than the maximum operating limit)
established for the parameter in accordance with the requirements of
paragraph (f)(1) of this section.
(4) Whenever an excursion occurs, the owner or operator shall
initiate within one hour of detecting the excursion the corrective
action procedures identified in the startup, shutdown, and malfunction
plan as necessary to restore the operation of the control device to the
proper operating settings. Failure to initiate the corrective action
procedures within one hour of detecting an excursion or to take the
necessary corrective actions to remedy the problem is a violation of
the standard in this subpart.
Sec. 63.1453 Notification requirements.
(a) The requirements of this section apply to the owner and
operator of a primary copper smelter that is subject to the
requirements of this subpart.
(b) The owner or operator shall prepare and submit written
notifications to the Administrator in accordance with Sec. 63.9 of the
general provisions in subpart A of this part.
Sec. 63.1454 Recordkeeping and reporting requirements.
(a) General. The requirements of this section apply to the owner
and operator of a primary copper smelter that is subject to the
requirements of this subpart.
(b) Recordkeeping requirements. The owner or operator shall prepare
and maintain, in accordance with the requirements in Sec. 63.10(b)(1)
of the general provisions in subpart A of this part, files of
information specified in paragraphs (b)(1) through (b)(9) of this
section. The owner or operator shall maintain records for a least 5
years from the date of each record. The records for the most recent 2
years of operation shall be maintained at the smelter site. Records for
previous years may be maintained at an off-site location.
(1) The occurrence and duration of each startup, shutdown, or
malfunction of operation (i.e., 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 periods of startup, shutdown, and
malfunction (including corrective actions to restore malfunctioning
process and air pollution control equipment to its normal or usual
manner of operation) when such actions are different from the
procedures specified in the affected source's startup, shutdown, and
malfunction plan prepared in accordance with the requirements of
Sec. 63.6 of the general provisions in subpart A of this part.;
[[Page 19612]]
(5) Information necessary to demonstrate compliance with the
affected source's startup, shutdown, and malfunction plan (prepared in
accordance with the requirements of Sec. 63.6 of this part) when all
actions taken during periods of startup, shutdown, and malfunction
(including corrective actions to restore malfunctioning process and air
pollution control equipment to its normal or usual manner of operation)
are consistent with the procedures specified in such plan. (The
information needed to demonstrate conformance with the startup,
shutdown, and malfunction plan may be recorded using a ``checklist,''
or another effective form of recordkeeping, to reduce the recordkeeping
burden for conforming events);
(6) Measurements and other supporting documentation needed to
demonstrate compliance with a relevant standard (including, but not
limited to, raw performance testing measurements, and raw performance
evaluation measurements, that support data that the source is required
to report);
(7) Results of all performance tests and opacity observations
performed in accordance with the requirements of this subpart;
(8) Data recorded to meet the applicable monitoring requirements of
Sec. 63.1452 of this subpart.
(9) Documentation supporting notifications submitted under
Sec. 63.1453 of this subpart.
(c) Reporting requirements. The owner or operator shall prepare and
submit written reports to the Administrator in accordance with
Sec. 63.10 of the general provisions in subpart A of this part.
Sec. 63.1455 State authority and delegations.
(a) In delegating implementation and enforcement authority to a
State under section 112(d) of the Act, the authority listed in
paragraph (b) of this section shall be retained by the Administrator
and not transferred to a State.
(b) Authority will not be delegated to States for approval of
alternative test methods under Sec. 63.1451 of this subpart.
Appendix A to Subpart QQQ--Applicability of General Provisions (40
CFR part 63, subpart A) to Subpart QQQ
------------------------------------------------------------------------
Applies to subpart
Citation QQQ Comment
------------------------------------------------------------------------
63.1............................ yes............... ..................
63.2............................ yes............... ..................
63.3............................ yes............... ..................
63.4............................ yes............... ..................
63.5............................ yes............... ..................
63.6 (a)-63.6 (g)............... yes............... ..................
63.6 (h)........................ no for existing Subpart QQQ
sources. specifies
requirements to
be used for
compliance with
the visible
emission limits.
63.6 (i)-63.6 (j)............... yes............... ..................
63.7............................ yes............... ..................
63.8............................ yes............... ..................
63.9 (a)-163.9 (e).............. yes............... ..................
63.9 (f)........................ no for existing Subpart QQQ
sources. specifies
notification
requirements for
visible emission
limit compliance
test.
63.9 (g)-63.9 (j)............... yes............... ..................
63.10........................... yes............... ..................
63.11........................... no................ Flares not used to
comply with
Subpart QQQ
standards.
63.12-63.15..................... yes............... ..................
------------------------------------------------------------------------
Figure 1.--Of Subpart QQQ Data Summary Sheet for Determination of Average Opacity
--------------------------------------------------------------------------------------------------------------------------------------------------------
Continuous 6-
Number of 1-minute average Blowing without minute average
Clock time converters Converter aisle activity opacity (percent) Interferences opacity
blowing (yes or no) (percent)
--------------------------------------------------------------------------------------------------------------------------------------------------------
--------------------------------------------------------------------------------------------------------------------------------------------------------
[FR Doc. 98-10142 Filed 4-17-98; 8:45 am]
BILLING CODE 6560-50-P