National Emission Standards for Hazardous Air Pollutants for Source Categories: National Emission Standards for Primary Copper Smelters

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

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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 contro

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