National Emission Standards for Hazardous Air Pollutants for Source Categories; National Emission Standards for Hazardous Air Pollutants for Primary Aluminum Reduction Plants

SUMMARY: This action promulgates national emission standards for each

new or existing potline, paste production plant, and anode bake furnace

associated with a primary aluminum reduction plant, and for each new

pitch storage tank associated with a primary aluminum production plant.

In addition, the new source performance standard for primary aluminum

plants is amended and most of the requirements are incorporated in the

final national emission standards. This action also adds Method 315 for

the measurement of extractable organic matter to appendix A of part 63

and Method 14A for the measurement of total fluoride (TF) to appendix A

of part 60.

The major hazardous air pollutants (HAPs) emitted by the facilities

covered by this rule include hydrogen fluoride (HF) and polycyclic

organic matter (POM). Polycyclic aromatic hydrocarbons (PAHs) are

included in the chemical group POM. Polycyclic aromatic hydrocarbons

have been reported to produce carcinogenic, reproductive, and

developmental effects as well as toxic effects on blood, the liver,

eyes, and the immune system. The final rule will result in a 50 percent

reduction in fluoride and POM emissions from the current level of

11,000 tons per year (tpy); a substantial reduction in emissions of

nonHAP pollutants, such as particulate matter, also will be achieved.

These standards implement section 112(d) of the Clean Air Act as

amended (the Act) and are based on the Administrator's determination

that primary aluminum plants may reasonably be anticipated to emit

several of the HAPs listed in section 112(b) of the Act from the

various process operations found within the industry.

EFFECTIVE DATE: October 7, 1997. See the SUPPLEMENTARY INFORMATION

section concerning judicial review.

The incorporation by reference of certain publications listed in

the rule is approved by the Director of the Federal Register as of

October 7, 1997.

ADDRESSES: Docket. The docket for this rulemaking containing the

information considered by the EPA in development of the final rule is

Docket No. A-92-60. This docket is available for public inspection

between 8 a.m. and 4 p.m., Monday through Friday except for Federal

holidays, at the following address: U.S. Environmental Protection

Agency, Air and Radiation Docket and Information Center (6102), 401 M

Street SW., Washington, DC 20460; telephone: (202) 260-7548. The docket

is located at the above address in Room M-1500, Waterside Mall (ground

floor). A reasonable fee may be charged for copying.

Background Information Document. A background information document,

titled ``National Emission Standards for Hazardous Air Pollutants

(NESHAP) for Primary Aluminum Reduction Plants--Background Information

for Promulgated Standards, Summary of Public Comments and Responses,''

has been prepared summarizing the significant public comments made on

the proposed rule and the Administrator's response to those comments.

This document is available in the docket for this rulemaking and also

is available for downloading from the Technology Transfer Network under

the Clean Air Act Amendments, Recently Signed Rules.

FOR FURTHER INFORMATION CONTACT: Steve Fruh, Policy, Planning, and

Standards Group, U.S. Environmental Protection Agency, Research

Triangle Park, North Carolina 27711, telephone number (919) 541-2837,

electronic mail address, ``[email protected]''.

SUPPLEMENTARY INFORMATION:

Regulated Entities

Entities potentially regulated by this action are those that emit

or have the potential to emit HAPs listed in section 112(b) of the Act.

Regulated categories and entities include:

------------------------------------------------------------------------

Examples of regulated

Category entities

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Industry.................................. Primary aluminum reduction

plants.

Federal government:

Not affected

State/local/tribal government:

Not affected.

------------------------------------------------------------------------

This table is not intended to be exhaustive, but rather provides a

guide for readers regarding entities likely to be regulated by this

action. This table lists the types of entities that EPA is now aware

could potentially be regulated by this action. Other types of entities

not listed in the table could also be regulated. To determine whether

your facility is regulated by this action, you should carefully examine

the applicability criteria in Sec. 63.840 of the final rule. If you

have any questions regarding the applicability of this action to a

particular entity, consult the person listed in the preceding FOR

FURTHER INFORMATION CONTACT section.

Judicial Review

This NESHAP for primary aluminum reduction plants was proposed on

September 26, 1996 (61 FR 50586). This notice promulgating a NESHAP for

primary aluminum reduction plants constitutes final administrative

action concerning that proposal. Under section 307(b)(1) of the Clean

Air Act, judicial review of this final rule is available only by filing

a petition for review in the U.S. Court of Appeals for the District of

Columbia Circuit by December 8, 1997. Under section 307(d)(7)(B) of the

Act, only an objection to this rule which was raised with reasonable

specificity during the period for public comment can be raised during

judicial review. Moreover, under section 307(b)(2) of the Act, the

requirements established by today's final action may not be challenged

separately in any civil or criminal proceeding brought by EPA to

enforce these requirements.

Technology Transfer Network

The Technology Transfer Network is one of the EPA's electronic

bulletin boards. The Technology Transfer Network 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-

5472 for up to a 14,400 bps modem. The Technology Transfer Network is

also accessible through the Internet at ``http://

ttnwww.rtpnc.epa.gov.'' If more information on the Technology Transfer

Network is needed, call the HELP line at (919) 541-5384.

Outline

The following outline is provided to aid in reading this preamble

to the final rule.

I. Statutory Authority

II. Purpose

III. Background

A. Primary Aluminum Source Category

B. NESHAP for Source Categories

[[Page 52385]]

C. Health Effects of Pollutants

IV. Summary of Final Rule and Changes Since Proposal

A. Applicability

B. Emission Limits and Standards

C. Incorporation of the NSPS

D. Emission Averaging

E. Compliance Provisions

F. Emission Monitoring

G. Test Methods

H. Time Limit for Approval or Disapproval of Submissions

I. Notification, Reporting, and Recordkeeping Requirements

J. Display of OMB Control Numbers

V. Summary of Impacts

VI. Summary of Responses to Major Comments

A. Subcategories

B. Format of the Standard

C. Achievability of Emission Limits

D. Incorporation of the NSPS

E. Time Limit for Approval by the Regulatory Authority

F. Relationship to Other Rules

G. Reduced Sampling Frequency

H. Approval of Alcan Cassette Method (Method 14A)

I. Estimates of Costs for Control and Monitoring

J. Exceeding an Operating Parameter Limit

K. Pitch Storage Tanks

VII. Administrative Requirements

A. Docket

B. Executive Order 12866

C. Enhancing the Intergovernmental Partnership Under Executive

Order 12875

D. Unfunded Mandates Reform Act

E. Regulatory Flexibility

F. Submission to Congress and the General Accounting Office

G. Paperwork Reduction Act

H. Clean Air Act

I. Statutory Authority

The statutory authority for this rule 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. Purpose

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).] Section 112 of the Act establishes a

technology-based program to reduce stationary source emissions of HAPs

from new and existing sources.

Section 112(d) of the Act requires the regulations to reflect the

maximum degree of reduction in emissions of HAPs that is achievable

taking into consideration the cost of achieving the emission reduction,

any non-air quality health and environmental impacts, and energy

requirements. This level of control is commonly referred to as the

maximum achievable control technology (MACT). The goal of the section

112(d) MACT standards is to apply such control technology to reduce

emissions and thereby reduce the hazard of HAPs emitted from stationary

sources.

This final rule is technology based, i.e., based on MACT. In

essence, these MACT standards ensure that all major sources of air

toxic emissions achieve the level of control already being achieved by

the better controlled and lower emitting sources in each category. This

approach provides assurance to citizens that each major source of toxic

air pollution will be required to effectively control its emissions. At

the same time, this approach provides a level economic playing field,

ensuring that facilities that use cleaner processes and good emission

controls are not disadvantaged relative to competitors with poorer

controls.

III. Background

A. Primary Aluminum Source Category

Section 112(c) of the Act requires the EPA to list each category of

major and area sources, as appropriate, emitting one or more of the

HAPs listed in section 112(b) of the Act. The term ``major source'' is

defined by the Act to mean:

* * *Any stationary source or group of stationary sources

located within a contiguous area and under common control that emits

or has the potential to emit, considering controls, in the aggregate

10 tons per year or more of any HAP or 25 tons per year or more of

any combination of HAPs.

On July 16, 1992 (57 FR 31576), the EPA published a list of major

and area sources for which NESHAP are to be promulgated, and primary

aluminum production was one of the 174 categories of sources listed.

The listing was based on the Administrator's determination that primary

aluminum plants may reasonably be anticipated to emit several of the

listed HAPs in sufficient quantity to be designated as major sources.

The EPA schedule for promulgation of the MACT standards was published

on December 3, 1993 (58 FR 63941), and requires that rules for the

primary aluminum source category be promulgated by November 15, 1997.

The primary aluminum source category includes facilities engaged in

producing primary aluminum by electrolytically reducing alumina. The

NESHAP for primary aluminum production applies to all primary aluminum

production plants because all of these sites are major sources.

B. NESHAP for Source Categories

The control of HAPs is achieved through the promulgation of

technology-based emission standards under section 112(d) and design,

equipment, work practice, or operational standards under section 112(h)

for categories of sources that emit HAPs. Emission reductions may be

accomplished through the application of measures, processes, methods,

systems, or techniques including, but not limited to: (1) Reducing the

volume of, or eliminating emissions of, such pollutants through process

changes, substitution of materials, or other modifications; (2)

enclosing systems or processes to eliminate emissions; (3) collecting,

capturing, or treating such pollutants when released from a process,

stack, storage, or fugitive emissions point; (4) design, equipment,

work practice, or operational standards (including requirements for

operator training or certification) as provided in subsection (h); or

(5) a combination of the above. (See section 112(d)(2).)

A statutory minimum or baseline level of HAP emission control that

the EPA can select to be MACT for a particular source category is

defined under section 112(d)(3) of the Act and is referred to as the

``MACT floor.'' For new sources, the MACT floor is the level of HAP

emission control that is achieved in practice by the best controlled

similar source. The statute allows standards under a NESHAP for

existing sources to be less stringent than standards for new sources.

The determination of MACT floor for existing sources depends on the

nationwide number of existing sources within the source category. The

floor is based on the average emission limitation achieved by the best-

performing 12 percent of existing sources for categories and

subcategories with 30 or more sources, or the best-performing 5 sources

for categories or subcategories with fewer than 30 sources.

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(d) of the Act requires EPA to establish emission

standards for

[[Page 52386]]

each category or subcategory of major and area sources. Section

112(d)(1) of the Act provides that the Administrator may distinguish

among classes, types, and sizes of sources within a category in

establishing such standards. In establishing subcategories, EPA

considers factors such as air pollution control engineering

differences, process operations (including differences between batch

and continuous operations), emission characteristics, control device

applicability, and opportunities for pollution prevention.

C. Health Effects of Pollutants

Available emission data, collected in conjunction with development

of the standard, show that the pollutants that are listed in section

112(b)(1) and are emitted by primary aluminum plants include HF, a

gaseous inorganic compound, and POM. Following is a summary of the

potential health effects caused by emission of pollutants that will be

reduced by the standard.

Short-term inhalation exposure to gaseous HF and related fluoride

compounds can cause severe respiratory damage in humans, including

severe irritation and pulmonary edema. Long-term inhalation exposure to

low levels of HF by humans has been reported to result in irritation

and congestion of the nose, throat, and bronchi while damage to liver,

kidney, and lungs has been observed in animals. Occupational studies

have not specifically implicated inhaled fluoride as a cause of cancer,

and the Agency has not classified HF with respect to potential

carcinogenicity.

There is generally a lack of information on human health effects

associated with exposures to HF at current ambient air concentrations

near primary aluminum plants. In their comments on the proposed rule,

the aluminum industry asserted that there was no evidence of adverse

effects on human health or the environment from HF emissions from

aluminum production at the industry's current level of emission

control.

Emission test results reveal that primary aluminum reduction plants

emit POM, which includes a combination of PAHs such as anthracene,

benzo(a)pyrene, and naphthalene, among others. Several of the PAH

compounds, including benzo(a)anthracene, benzo(a)pyrene,

benzo(b)fluoranthene, benzo(k)fluoranthene, chrysene,

dibenzo(a,h)anthracene, and indeno(1,2,3-cd)pyrene, are probable human

carcinogens. Cancer is the major concern from exposure to these PAHs.

Specifically, long-term exposure to benzo(a)pyrene has been reported to

result in toxic effects on skin, irritation to eyes, cataracts in

humans, and toxic effects on the liver, blood, and the immune system in

animal studies. Reproductive and developmental effects from

benzo(a)pyrene have also been reported in animal studies.

In addition to HAPs, this final standard also would reduce

emissions of particulate matter smaller than 10 microns in diameter

(PM10), which are controlled under the National Ambient Air

Quality Standards (NAAQS). The health effects of PM10 are

described in EPA's criteria documents that support the NAAQS. For

example, particles addressed by the PM10 standard have been

associated with aggravation of existing respiratory and cardiovascular

disease and increased risk of premature death.

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 depends upon: (1) The ambient

concentrations observed in the area (e.g., as influenced by emission

rates, meteorological conditions, and terrain), (2) the frequency of

and duration of exposures, (3) characteristics of exposed individuals

(e.g., genetics, age, pre-existing health conditions, and lifestyle),

which vary significantly with the population, and (4) pollutant-

specific characteristics (e.g., toxicity, half-life in the environment,

bioaccumulation, and persistence).

IV. Summary of Final Rule and Changes Since Proposal

Changes have been incorporated into the final NESHAP for primary

aluminum reduction plants in response to comments on the proposed rule.

The principal changes made since proposal are summarized below.

A. Applicability

As proposed, the final standard applies to emissions of HF,

measured using TF as a surrogate, and POM (as measured by methylene

chloride extractables) from each affected source associated with

primary aluminum reduction and located at a major source.

Under the proposed standard, affected sources included each new and

existing potline of reduction cells, anode bake furnace, and paste

production plant, except for one off-site anode bake furnace that is

subject to the State MACT determination established by the applicable

regulatory authority. No changes were made to the final standard

affecting the applicability of the rule to these affected sources.

In response to public comments, the applicability of the proposed

rule was revised to include new pitch storage tanks. The control

technology and standards applicable to this affected source are

summarized in section IV.B of this document.

Following proposal, the EPA's Office of Solid Waste (OSW) received

information that one primary aluminum plant has recently installed a

new process designed to recycle spent potliner from aluminum reduction

cells. Spent potliner is listed as a hazardous waste under the Resource

Conservation and Recovery Act. This process vitrifies the waste into a

glass material and recovers sodium fluoride and calcium fluoride for

use in the aluminum production process. Although the process is not

defined as an affected source under the final MACT rule, the Office of

Air Quality Planning and Standards (OAQPS) and OSW are working in

cooperation with the State agency and the plant to evaluate potential

air emissions (e.g., emission testing will be performed in the near

future) and to determine whether additional emission control

requirements beyond those currently required by the State are needed.

B. Emission Limits and Standards

No changes were made to the control options serving as the basis of

the proposed standards. The emission control technology selected as the

basis of the standards is discussed in section III.C of the proposal

preamble document (61 FR 50588, September 26, 1996).

Three changes were made to the emission limits and standards in

Secs. 63.843 and 63.844 of the proposed rule. The POM emission limit

for the VSS2 subcategory was reduced from 3.7 lbs/ton to 3.6 lbs/ton

based on data received for the MACT floor potline from that

subcategory. Section 63.843(b)(3) of the proposed rule concerning use

of an alternative control device for paste production plants was

revised to encourage pollution prevention options. Section 63.844 of

the proposed rule also was revised to include new paragraph (d)

containing provisions for new pitch storage tanks. No other changes

were made to the proposed limits and standards for potlines or anode

bake furnaces. These limits are summarized in Tables 1 and 2 of the

proposal preamble document (61 FR 50588-50589, September 26, 1996).

No changes were made to the proposed equipment standard developed

under section 112(h) of the Act that required a dry coke scrubber for

the paste production plant. The EPA

[[Page 52387]]

concluded that it was not feasible or practicable to develop a

defensible quantitative emission limit because there were too few POM

data available. However, the available information and engineering

judgement indicated that the best POM control technology in use for

paste plants was the dry coke scrubber, which was determined to

represent MACT.

The proposed provisions in Sec. 63.843(b)(3) that qualify

alternatives to the dry coke scrubber for paste production plants were

revised in response to public comments to encourage pollution

prevention measures, such as reducing the quantity of POMs used in

paste production. The control efficiency standard that was proposed was

replaced with POM emission limits for batch and continuous mixers in

terms of pounds of POM per ton of paste. With this approach, an

affected plant would not be penalized for using pollution prevention

measures that reduce uncontrolled emissions. This change will encourage

innovative or pollution prevention measures, such as reducing the

quantity of POMs used in the paste operation. The alternative limit in

lb/ton does not preclude plants from petitioning for other alternative

means of emission limitation under section 112(h)(3) of the Act based

on demonstrating an equivalent or greater emission reduction. A

detailed discussion is provided in section VI.B of this document.

Section 63.844 of the proposed rule was revised to include new

paragraph (d) establishing standards for new pitch storage tanks. New

paragraph (d) requires that each new pitch storage tank be equipped

with an emission control system designed and operated to reduce inlet

emissions of POM by 95 percent or greater. Compliance and monitoring

provisions are summarized in sections IV.E and IV.F of this document.

C. Incorporation of the NSPS

In response to comments on this issue, the EPA incorporated the

provisions of the new source performance standard (NSPS) in subpart S

of part 60 into a new section (Sec. 63.845) of the final rule and added

appropriate definitions from the NSPS. Also, the NSPS was amended to

allow the owner or operator to comply with either the NSPS or with the

special provisions that were incorporated into Sec. 63.845. With this

change, any modified, reconstructed, or new potroom group that would

have triggered the NSPS may now use the special provisions in the

NESHAP to demonstrate compliance. Sampling and monitoring were

streamlined by using the MACT requirements and by developing a single

emission limit for a potline rather than overlapping limits for both

the potline and the affected potroom group. The NSPS opacity limit was

also incorporated.

D. Emission Averaging

Only one change was made to the emission limits in Sec. 63.845 of

the proposed NESHAP pertaining to emission averaging for potlines and

anode bake furnaces. The POM limits for the VSS2 subcategory were

reduced based on data collected for the MACT floor potline from that

subcategory. The proposed limits are summarized in Tables 3 and 4 of

the proposal preamble document (61 FR 50591, September 26, 1996). This

section is renumbered as Sec. 63.846 in the final rule.

The final standard contains provisions allowing the owner or

operator to demonstrate compliance through averaging emissions of TF

from all existing potlines, POM from existing Soderberg potlines, and

TF and POM from existing anode bake furnaces (i.e., averaging is not

allowed for new sources). Averaging between pollutants (TF and POM) is

not allowed. The final standard also limits averaging to like sources

(i.e., TF emissions from a potline can be averaged only with TF

emissions from another potline at the same plant site). Emission

averaging would not be allowed in any State that selects to exclude

this option from its approved permitting program.

Monthly TF and quarterly POM limits for each group of potlines (two

or more lines) are included in the rule. Under this approach, the owner

or operator samples TF and/or POM emissions from at least three runs

each month/quarter for each potline in the group to determine the

average emissions from each potline. A minor revision was made to the

wording in Sec. 63.845(d)(2) of the proposed NESHAP (Sec. 63.846(d)(2)

of the final rule) to clarify that monthly average potline emissions

are determined from each potline from at least three runs per potline

each month for TF secondary emissions and/or the quarterly average

emissions from at least one run each month for POM emissions using the

procedures and methods in Secs. 63.847 and 63.849 of the final rule

(emphasis added). As proposed, the sum of emissions from each potline

is divided by total aluminum production from all of the potlines for

the month (or for the quarter for POM) to determine the emissions in

lb/ton for comparison to the applicable emission limit.

Section 63.846(d) of the NESHAP describes the requirements for an

emission averaging implementation plan. The proposed standard required

that unless an operating permit application has been submitted, the

owner or operator must develop and submit an implementation plan for

emission averaging to the applicable regulatory authority for review

and approval. This language was revised to remove the misleading phase,

``unless an operating permit application has been submitted'' to

clarify that each owner or operator desiring to participate in emission

averaging must develop and submit an implementation plan. Paragraph

(d)(2) of this section clearly states that the owner or operator must

include the specified information in an implementation plan or in the

application for an operating permit.

The language in Sec. 63.845(d)(1) of the proposed NESHAP pertaining

to the deadline for submission of the plan also was revised. Section

63.846(d)(1) of the final rule clarifies that the plan is to be

submitted 6 months before the facility intends to comply with the

emission averaging limits rather than 6 months before the applicable

compliance date.

The content of the implementation plan is described in

Sec. 63.846(d)(2) of the final rule. The proposed rule required that

this information include the emission sources to be averaged, the

applicable limit assigned to each averaging group, the specific control

technology or measure to be used for each source in the group, the

results of an initial performance test, the operating parameters to be

monitored (with additional information if an alternative parameter is

monitored), and a demonstration that compliance with each of the

applicable limits will be achieved under representative operating

conditions. A clarifying change was made in the final rule to delete

the requirement for submission of the results of an initial performance

test to determine the TF or POM emissions and emission reduction from

each source in the averaging group. This provision was replaced with a

requirement for a test plan to measure TF or POM emissions in

accordance with the performance test requirements in Sec. 63.847.

Section 63.847 requires a performance test to be conducted during the

first month following the applicable compliance date.

As proposed, the owner or operator may submit a request to revise

the plan, or if emission averaging is not selected initially, the owner

or operator may submit a request to implement emission averaging after

the compliance date.

[[Page 52388]]

This standard is not the first NESHAP to include provisions

permitting emission averaging. However, the mechanism by which EPA has

previously permitted owners and operators to average emissions has been

to define the affected source governed by the standard broadly enough

such that it includes all emission points to be averaged. Under this

model, which was first employed in the Hazardous Organics NESHAP

(``HON''), 59 FR 19402, 19425-34, April 22, 1994, compliance by

particular units within a broadly defined source is only an element in

determining the overall compliance with the standard by the aggregate

source. For this type of standard, conformity of the quantitative

standard to the MACT floor provision in section 112(d)(3) is determined

for the source as a whole, and averaging or trading between discrete

emission points within the source presents no potential conflict with

the MACT floor provision.

The HON approach to averaging affords substantial flexibility, by

permitting averaging of dissimilar emission points and differing

pollutants. However, there are also potential disadvantages to this

approach to averaging. Heterogeneous emission points are deemed to be

part of one affected source, rather than discrete sources that can be

subcategorized and regulated in relatively homogeneous groups. New

sources often must be defined more narrowly than existing sources in

order to ensure that state-of-the-art controls are required for

technically discrete new units.

The final primary aluminum NESHAP takes a different approach to

averaging from the HON approach. In this standard, owners or operators

are permitted to average across sources in determining overall

compliance with the standard. In the HON rulemaking, EPA expressed

concern that averaging across sources could be incompatible with the

MACT floor provisions. However, upon further analysis, EPA has decided

that averaging across affected sources is neither expressly permitted

nor expressly precluded by the Clean Air Act. Thus, in construing the

statute, EPA has focused instead on identifying those circumstances in

which averaging across sources would be fully consistent with the

overall statutory intent.

In general, EPA has concluded that it is permissible to establish

within a NESHAP a unified compliance regimen that permits averaging or

trading across affected sources subject to the standard under certain

conditions. Averaging across affected sources is permitted only if it

can be demonstrated that the total quantity of any particular HAP that

may be emitted by that portion of a contiguous major source that is

subject to the NESHAP will not be greater under the averaging mechanism

than it would be if each individual affected source complied separately

with the applicable standard. Under this rigorous test, the practical

outcome of averaging is equivalent in every respect to compliance by

the discrete sources, and the statutory policy embodied in the MACT

floor provisions is therefore fully effectuated. A construction of the

Act which permits EPA to establish a unified compliance regimen in

these limited circumstances promotes economic efficiency and has no

adverse environmental consequences. In a NESHAP incorporating such a

unified compliance regimen, EPA would construe compliance with the

overall regimen to constitute compliance for each of the affected

sources.

Strict limits on the scope and nature of averaging across sources

are necessary to ensure that no HAP is emitted by that portion of a

major source subject to a NESHAP in quantities that are greater than

those that would result from compliance by each discrete affected

source within the facility. These limits include: (1) No averaging can

be permitted between differing pollutants, (2) no averaging can be

permitted between sources that are not part of the same major source,

(3) no averaging can be permitted between sources within the same major

source that are not subject to the same NESHAP, (4) statistical

discounts must be derived and applied to account for the variability in

emissions by the sources to be averaged, and (5) no averaging can be

permitted between existing sources and new sources.

This NESHAP fully satisfies each of these criteria. Accordingly,

EPA has concluded that the averaging of emissions across affected

sources permitted by this NESHAP is consistent with the Clean Air Act.

In addition, EPA notes that the provision in this NESHAP that requires

each facility that intends to utilize emission averaging to submit an

implementation plan provides additional assurance that the necessary

criteria will be adhered to.

E. Compliance Provisions

Compliance with the standard must be demonstrated at startup for

new sources and in 2 to 4 years from the effective date of the final

rule for existing sources. All existing plants would be allowed at

least 2 years. An extension for a fourth year may be granted by the

regulatory authority under section 112(i)(3)(B) of the Act.

Few changes were made to Sec. 63.846 of the proposed rule

concerning requirements for performance tests. Following approval of a

site-specific test plan, Sec. 63.847 of the final rule requires the

owner or operator to conduct an initial performance test during the

first month following the compliance date. A clarification was made to

Sec. 63.846(d) of the proposed rule (Sec. 63.847(c) of the final rule)

that not all of the primary emission control devices have to be sampled

during the first month of compliance. If valid emission test results

are available for the control device from tests during the preceding 12

months, those results can be used to determine the contribution of the

primary control system to the total emissions for the initial

performance test.

Section 63.847(d), which contains instructions for determining

compliance, also includes clarifying revisions. Sections 63.847(d)(1)

of the final standard clarifies that to determine compliance for TF

emissions from potlines, the owner or operator must compute and record

the average of at least three runs each month for secondary emissions

and at least three runs each year for the primary control device.

Section 63.847(d)(2) clarifies that to determine compliance for POM

emissions from Soderberg potlines, the average of at least three runs

each quarter (one run per month) for secondary emissions and at least

three runs each year for the primary control system is required.

Compliance with the applicable emission limits for anode bake plants is

determined by the average of at least three runs each year. Section

63.847(d)(3) clarifies that the provisions for previous control device

tests include anode bake furnaces as well as potlines.

Section 63.847(e) of the final rule also includes minor changes to

clarify the equations used to determine compliance. Editorial changes

were made to correct misnumbering of Equations 1 and 2. In Equation 1,

the definition of Qsd was clarified to read as the

volumetric flow rate of effluent gas ``corresponding to the appropriate

subscript location'' with units of dry standard cubic meters per hour

(dscm/hr) or dry standard cubic feet per hour (dscf/hr). The

instructions for determining the aluminum rate (P) in

Secs. 63.846(e)(6) and (e)(7) also were revised. Sections 63.847(e)(6)

and (e)(7) of the final rule require the owner or operator to determine

the aluminum production rate by dividing the number of hours in the

calendar month into the weight of aluminum tapped from the

[[Page 52389]]

potline during the calendar month that includes the three runs of a

performance test. The rate of green anode material introduced into the

furnace is determined by dividing the number of operating hours in the

calendar month into the weight of green anode material used during the

calendar month in which the performance test was conducted.

No changes were made to the proposed performance test provisions

for paste production in Sec. 63.847(f) of the final rule. Initial

compliance with the equipment standards for new and existing plants is

demonstrated through site inspections(s) and review of site records by

the applicable regulatory authority.

A new paragraph, Sec. 63.847(g), was added to describe compliance

provisions for new pitch storage tanks. The owner or operator may elect

one of two methods of demonstrating compliance: (1) Submit a design

evaluation documenting that the control device being used achieves the

required control efficiency for POM (95 percent or more) during a

reasonably expected maximum filling rate; or (2) submit the results of

a performance test. Specific information to be included under either

method of compliance is described in the rule. The owner or operator

also would include a description of the parameters to be monitored to

ensure the control device is being properly operated and maintained, an

explanation of the criteria used to select that parameter, and the

frequency with which monitoring will be performed.

Section 63.846(g) of the proposed rule was renumbered as

Sec. 63.847(h) in the final rule to accommodate the addition of the

preceding paragraph. Minor changes were made to clarify the wording in

paragraph (h), which requires that the owner or operator determine the

parametric operating limits and monitoring frequency for each control

device. Section 63.847(h)(1) of the final rule clarifies that for

potlines and anode bake furnaces, the owner or operator must determine

upper and/or lower operating limits, as appropriate, for each

monitoring device ``for the emission control system'' from the values

recorded during each of the runs performed during the initial

performance test and from historical data from previous performance

tests. The wording of Sec. 63.847(h)(2) also was clarified to require

the owner or operator of a paste production plant to specify parameters

to be monitored and operating limits for the emission control device

(rather than the emission capture and control devices). References to

the part 70 operating permit were deleted.

F. Emission Monitoring

Few changes were made since the proposal in the emission monitoring

requirements of Sec. 63.848. The final standard requires the owner or

operator to perform monthly sampling of TF secondary emissions from

each potline using Methods 13 and 14 (40 CFR part 60, appendix A) or an

approved alternative method. Emissions of POM from Soderberg potlines

are monitored by performing quarterly sampling of POM using Method 315

or an approved alternative method. The monthly average for TF and the

quarterly average for POM are computed using the results of at least

three runs per month for secondary emissions of TF and at least one run

per month (three runs per quarter) for POM from Soderberg potlines, the

aluminum production rate, and the most recent compliance test for the

primary control system. Sections 63.848(a) and (b) clarify that the

duration of each run for secondary emissions must cover a complete

operating cycle. Under Sec. 63.848(b), the primary control system for

POM emissions must be sampled over an 8-hour period, unless site-

specific factors dictate an alternative sampling time, subject to the

approval of the regulatory authority. Annual sampling of TF using

Method 13 and POM (for Soderberg potlines) using Method 315 is required

for the primary emission control system for potlines. Annual sampling

of TF using Method 13 and POM using Method 315 is required for the

anode bake furnace stack.

Section 63.848(d) of the rule provides an alternative to monthly

monitoring of TF or POM secondary emissions from each potline by

allowing the owner or operator to conduct a monthly performance test

for one potline using reference test methods and to monitor similar

potline(s) using approved alternative methods. In response to public

comment, the criteria for similar potlines were revised to require that

their structure, operability, type of emissions, and volume and

concentration of emissions be substantially equivalent.

Section 63.848(d) provides that a similar potline is to be

monitored using an alternative method meeting the requirements in the

rule. An approved alternative may include an HF continuous emission

monitor (CEM). Because the Alcan cassette method is included in the

final rule as Method 14A, references to this method as an approved

alternative for monitoring similar potlines were unnecessary and were

deleted from the rule.

To show that another method is an acceptable alternative, the owner

or operator must develop a correlation with results from the applicable

methods in the rule (such as Methods 13, 14, and 315) to the

satisfaction of the regulatory authority. For fluoride measurements,

the alternative method must account for or include gaseous fluoride and

cannot be based on measurement of particulate matter or particulate

fluoride alone because HF, the HAP of interest, is in gaseous form. The

final rule also requires the owner or operator to derive an alternative

limit for the HF CEM or other alternative monitoring method. The owner

or operator must demonstrate that the alternative method and limit will

result in a level of emission control that is the same as or better

than the level that would have otherwise been achieved. After

demonstrating that the potlines are similar, EPA methods must be used

to monitor one potline, and the other similar potlines must be

monitored using an approved alternative procedure.

Under Sec. 63.848(e) of the final standard, the owner or operator

of a plant that demonstrates consistent compliance with an applicable

emission limit and low variability may apply for a reduced sampling

frequency, such as quarterly sampling instead of monthly sampling. This

section of the proposed rule was changed after proposal to provide a

simplified procedure to obtain reduced sampling frequency, including

removal of the requirement to publish the approval of reduced sampling

in the Federal Register. This reduced sampling provision was clarified

to apply only to the monthly sampling requirement for TF from potroom

roofs. If a facility achieves a long-term average over 24 months of

sampling that is no more than 60 percent of the applicable limit and no

monthly average exceeds 75 percent of the limit, then monthly sampling

for TF can be reduced to quarterly sampling.

Proposed provisions governing excess emissions also were revised.

Under the final rule, if emissions in excess of the applicable TF limit

occur while performing quarterly sampling (under an approved

alternative), the owner or operator must return to monthly sampling for

at least 12 months and may reduce to quarterly sampling when: (1) The

average of all tests performed over the most recent 24-month period

does not exceed 60 percent of the applicable limit and (2) no more than

one monthly performance test in the most recent 24-month period exceeds

75 percent of the

[[Page 52390]]

applicable limit. If emissions in excess of the applicable TF limit

occur while performing quarterly sampling (under an approved

alternative), the owner or operator must return to the monthly sampling

schedule until another request for an alternative sampling frequency is

approved.

The final standard requires the monitoring of control device

parameters. For example, plants with dry alumina scrubbers must perform

a daily visual inspection of the stack and install devices to monitor

the flow of alumina and air. The control device parameters are

evaluated from data collected during the initial performance test and

from historical performance tests to determine upper and/or lower

limit(s), as appropriate, for each process parameter. The owner or

operator may redetermine the upper and/or lower operating limits, as

appropriate, based on historical data and other information and submit

an application to the regulatory authority to change the applicable

limit(s). A corrective action program is triggered if the control

device is operating outside of the acceptable range for the specified

parameters. Failure to initiate corrective actions within 1 hour after

exceeding the limit is a violation. A violation also occurs if the

operating limit for a parameter is exceeded more than six times in any

6-month reporting period. For the purpose of determining the number of

exceedances, no more than one exceedance will be attributed in any

given 24-hour period.

A clarification was made to Sec. 63.848(f) with respect to the

selection of monitoring parameters and frequency. Whenever practicable,

the EPA expects the owner or operator to install a continuous parameter

monitoring system as defined in the general provisions and this

subpart. At a minimum, the owner or operator must submit a description

of the parameters and a rationale for selecting the operating limits

and monitoring frequency. A discussion of how the selected parameters

would relate to emission controls must be included.

The owner or operator also must install devices to measure the

daily weight of aluminum produced and the weight of anodes placed in

the furnace for an operating cycle. The total weight of all anodes

placed in the furnace may be measured, or the number of anodes placed

in the furnace and a representative weight may be measured to determine

the total weight.

G. Test Methods

Section 63.849 of the final rule adds Method 14A to appendix A of

40 CFR part 60 as an approved alternative method for measuring TF from

potroom roofs. Minor changes were made to Method 315 (added to appendix

A of 40 CFR part 63) as a result of public comment. For example,

section 6.1 of Method 315 was revised to acknowledge that the use of

grease for sampling train components is not recommended because many

greases are soluble in methylene chloride. Section 6.2 of Method 315

was revised to include the use of Teflon bristle brushes and

tetrafluoroethylene (TFE) wash bottles. A Buchner fritted funnel was

substituted for Allihin tubes in section 6.3.8 and other sections.

Section 63.849(e) of the final rule was clarified in terms of

procedures and criteria to qualify an alternative test method. The

alternative method must be evaluated from simultaneous sampling using a

reference test method. Approval is granted only if the owner or

operator demonstrates that the level of emission control from an

alternative method and alternative emission limit is the same as or

better than the level that would have otherwise been achieved.

H. Time Limit for Approval or Disapproval of Submissions

The proposed rule was revised to add a new section (Sec. 63.851)

that places a 60-day limit on the amount of time for the regulatory

authority to indicate the need for additional time to review the

applications and requests for changes allowed under this rule or to

approve or disapprove applications and requests for changes allowed

under the rule. The 60-day period begins after the owner or operator

has been notified that the submission is complete. This provision

applies to the compliance test plan, an application to change control

device parameter operating limits, requests for alternative monitoring

for similar potlines, requests for approval of alternative methods for

sampling and analysis, and requests for reduced sampling frequency.

I. Notification, Reporting, and Recordkeeping Requirements

Notification, reporting, and recordkeeping requirements for MACT

standards are included in the NESHAP general provisions (40 CFR part

63, subpart A). Section 63.850 of the final standard incorporates all

of these provisions, except that the existing performance

specifications for CEM are not applicable to an HF CEM because such

specifications have not yet been developed for that device.

The notification requirements include one-time notifications of

applicability, intent to construct or reconstruct, anticipated startup

date, actual startup date, date of performance test, compliance status,

compliance approach (if applicable), and the intent to use an HF CEM

(if applicable) for each affected source. The notification of special

compliance obligations was deleted because it does not apply to this

source category. The proposed rule also was revised to indicate that

the notification of the intent to use an HF CEM was a one-time event

per affected source.

The owner or operator is required to submit a report of performance

test results (which can be sent as part of the compliance status

notification), an annual summary of all subsequent tests, and

semiannual reports of excess emissions, if any excess emissions

occurred. If excess emissions are reported, quarterly reports are

required until compliance has been demonstrated for 1 year. A startup,

shutdown, and malfunction plan also would be required with semiannual

reports of events that are not managed according to the plan. The plan

must also include the corrective actions to be taken if the limit for a

control device's operating parameter is exceeded.

Recordkeeping requirements for all MACT standards are established

in Sec. 63.10(b) of the general provisions. In addition to these

requirements, the standard requires plants to maintain records of

information needed to determine compliance. Section 63.850(e)(4)(ii) of

the final rule clarifies that the owner or operator must maintain the

daily production rate of green anode material placed in the anode bake

furnace (rather than the production rate for each operating cycle). A

new recordkeeping requirement was also added in response to public

comment. Section 63.850(e)(4)(xv) requires records documenting the

portion of TF that is captured and measured as particulate matter and

the portion that is captured and measured as gaseous. This requirement

provides potentially useful information to EPA and the States at no

additional cost.

All records must be retained 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 onsite; records for the remaining 3 years may be retained

offsite but still must be readily available for review. The files may

be retained on microfilm, on microfiche, on a computer, or on computer

or magnetic disks.

[[Page 52391]]

J. Display of OMB Control Numbers

In a separate rulemaking action taken in conjunction with the final

rule adopting a NESHAP for primary aluminum reduction plants, EPA is

amending the table of currently approved information collection request

(ICR) control numbers issued by the Office of Management and Budget

(OMB) for various regulations. This separate amendment updates the

table to accurately display those information requirements contained in

the NESHAP. This display of the OMB control number and its subsequent

codification in the Code of Federal Regulations satisfies the

requirements of the Paperwork Reduction Act (44 U.S.C. 3501 et seq.)

and OMB's implementing regulations at 5 CFR 1320.

The ICR was previously subject to public notice and comment prior

to OMB approval. As a result, EPA finds there is ``good cause'' under

section 553(b)(B) of the Administrative Procedure Act [5 U.S.C.

553(b)(B)] to amend this table without prior notice and comment. Due to

the technical nature of the table, further notice and comment would be

unnecessary. For the same reasons, EPA also finds that there is good

cause under 5 U.S.C. 553(d)(3).

V. Summary of Impacts

Nationwide emissions from primary aluminum potlines are estimated

at 6,400 tpy of TF. After implementation of the final standards, these

emissions will decrease by almost 50 percent to 3,400 tpy. Polycyclic

organic matter emissions will be reduced by about 45 percent, from

3,200 tpy to 1,800 tpy. TF emissions from the anode bake furnaces are

estimated at 700 tpy; POM emissions are estimated at 555 tpy. After

control of all bake furnaces, TF emissions will be reduced by 97

percent, and POM emissions will be reduced by 84 percent. Polycyclic

organic matter emissions from paste production plants, estimated at 147

tpy at baseline, will be reduced by about 130 tpy, to about 16 tpy--an

89 percent reduction from current levels. Emissions of other HAPs

included in the TF and POM emissions will also be reduced, as will non-

HAP pollutants such as PM. For example, PM emissions will be reduced by

16,000 tpy.

The generation of solid waste and wastewater will be reduced when

at least one plant replaces its wet scrubber system with a dry alumina

scrubber. The dry alumina scrubber captures fluorides and other

pollutants and returns them to the reduction cell. The proposed rule is

estimated to have no significant effect on energy consumption.

The total capital cost of the proposed rule is estimated as about

$160 million, with a total annualized cost of $40 million per year. As

discussed in section VI.I of this document, cost estimates supplied by

the industry's trade association were much higher than the EPA

estimates. The major cost impacts for potlines are expected to come

from the installation of dry alumina scrubbers for the primary control

system at one plant and from work practices, operating procedures,

maintenance and repair, and equipment modifications at most plants. A

few plants may incur capital costs to replace or upgrade hoods or doors

and to install automated equipment for improved emission control.

The cost estimates for paste production assume that the 18 plants

without dry coke scrubbers for controlling POM emissions will each

install one. However, some plants may be able to meet the performance

standard with dry alumina scrubbers or other control devices, or they

may be able to utilize many of the components of their existing system.

The estimated cost for control of anode bake furnaces assumes that the

5 of 17 plants without a dry alumina scrubber must each install one.

Currently, about one-third of existing potlines are sampled for TF

regularly. Because of the flexibility provided in the rule, many plants

are expected to take advantage of the use of HF CEMs and Alcan

cassettes for similar potlines, both of which are much less expensive

than manual sampling using Methods 13 and 14. The nationwide capital

cost estimate of $7 million for monitoring equipment includes new

Method 14 manifolds, HF CEMs, and Alcan cassettes. The total annualized

cost of monitoring (including capital recovery) is estimated as about

$4 million per year after all plants are subject to the rule. These

costs may be reduced significantly as plants qualify for reduced

sampling frequency (e.g., quarterly instead of monthly). The CEM will

have value as a process monitoring tool in addition to its use for

monitoring to determine compliance.

The market price increase calculation indicated that implementing

the controls will result in a primary aluminum market price increase of

less than 1 percent. As a result of the low market price increase and

relatively inelastic demand, the corresponding changes in output,

employment, and total revenue were also low (all less than 1 percent).

Therefore, the economic impact analysis estimates that the rule will

not result in significant economic impacts for the primary aluminum

industry.

VI. Summary of Responses to Major Comments

The EPA proposed the NESHAP for primary aluminum reduction plants

on September 26, 1996 (61 FR 50586). The proposed regulatory text of

the rule, the Basis and Purpose Document, and the Technical Support

Document that presented information used in developing the proposed

rule were made available to the public for review and comment. A 60-day

comment period from September 26, 1996, to November 25, 1996, was

provided to accept written comments from the public on the proposed

rule. The opportunity for a public hearing was provided to allow

interested people to present oral comments to the EPA on the

rulemaking. However, the EPA did not receive a request for a public

hearing, so a public hearing was not held.

The EPA received a total of 15 comment letters regarding the

proposed NESHAP for primary aluminum reduction plants. A copy of each

comment letter is available for public inspection in the docket for the

rulemaking (Docket No. A-92-60; see the ADDRESSES section of this

document for information on inspecting the docket). The EPA has had

follow-up discussions with various commenters regarding specific issues

initially raised in their written comments that were submitted to the

Agency during the comment period. Copies of correspondence and other

information exchanged between the EPA and the commenters during the

post-comment period are available for public inspection in the docket

for the rulemaking.

All of the comments received by the EPA were reviewed and carefully

considered by the Agency. Changes to the rule were made when the EPA

determined it to be appropriate. A summary of responses to selected

major comments received on the proposed rule is presented below.

Additional discussion of the EPA's responses to public comments is

presented in the Background Information Document (see the ADDRESSES

section of this preamble).

A. Subcategories

Comment: Several commenters supported the subcategories that were

developed for potlines, and two commenters questioned the number of and

basis for the subcategories. Specific questions were raised about the

subcategories for the older vintage

[[Page 52392]]

prebake potlines (CWPB2), for potlines producing high-purity aluminum

(CWPB3), and for the vertical stud Soderberg potlines (VSS2).

Response: The development of subcategories is discussed in detail

in the Basis and Support Document. In general, the subcategories are

based primarily on differences in the process operation, process

equipment, emissions, and the applicability of control devices.

A distinction was made between the larger and more modern prebake

potlines in CWPB1 and the smaller and older potlines in CWPB2. The

CWPB2 potlines have somewhat higher emissions than the CWPB1 potlines

because they are more difficult to control and there are more

opportunities for fugitive emissions to escape. A major factor is that

these smaller potlines require more frequent anode changes and more

frequent opening of the reduction cells, both of which result in more

fugitive emissions' escaping from the cells.

The potlines in the CWPB3 subcategory that produce high-purity

aluminum can do so only because they use wet scrubbers as the primary

control device and do not return the contaminants removed with the

pollution control residue back to the process. In contrast, the

potlines in the CWPB1 subcategory use dry alumina scrubbers as the

primary control device and return pollution control residue, including

contaminants and fluorides, back to the process. If the CWPB3 potlines

were forced to install dry alumina scrubbers, an adequate quantity of

high-purity aluminum could not be produced and their market would be

lost.

A distinction was made between two types of vertical stud Soderberg

potlines (VSS1 and VSS2) because of differences in the applicability of

control devices. The VSS1 group of potlines uses wet roof scrubbers to

control fugitive emissions from the cells, and the VSS2 group of

potlines uses work practices and equipment maintenance to control the

escape of fugitive emissions from the cells (i.e., they focus on

pollution prevention for emission control). A major concern in

requiring the installation of wet roof scrubbers on the VSS2 potlines

was that other plants with wet roof scrubbers had reported operational

problems in cold weather (i.e., freezing conditions), and the VSS2

potlines operate in the cold climate of northern Montana. Consequently,

the technology was judged not to be adequately demonstrated for the

VSS2 potlines. Another concern was that roof scrubbers could provide a

disincentive for the VSS2 potlines to continue their efforts to prevent

the escape of emissions because the emissions would be subsequently

controlled by the scrubbers. Currently, the VSS2 potlines have much

lower levels of fugitive emissions in terms of the quantity that

actually escapes from the reduction cells compared to the VSS1

potlines, which rely in large part on the roof scrubbers for additional

fugitive emission control.

B. Format of the Standard

Comment: Two State commenters asked that EPA consider developing

work practice standards for potlines, and some commenters also

suggested that an emission limit be developed for paste plants instead

of an equipment standard.

Other commenters supported the development of an equipment standard

for paste plants. Commenters also asked that EPA consider alternatives

for the paste plant that would allow and encourage pollution

prevention, as well as other control alternatives that might be

equivalent to or better than the equipment standard that was proposed

(dry coke scrubber).

Response: Section 112(h) of the Act only allows development of a

design, equipment, work practice, or operational standard when it is

not feasible or practicable to establish an emission standard.

Consequently, a work practice standard was not developed for potlines

because there was an extensive database on TF emissions on which to

base an emission standard. An emission standard allows the owner or

operator to meet the emission limit using any combination of control

techniques, including work practices, upgrading equipment, process

modifications, pollution prevention, etc. It also provides flexibility

for developing innovative controls or pollution prevention measures in

the future that may be more cost effective by not mandating work

practice techniques. The owner or operator will find it necessary to

have adequate work practices in place to meet the emission limits in

the rule; consequently, it is not necessary to develop a work practice

standard.

The first choice was also the development of an emission standard

for paste production plants; however, there were too few POM data (only

two data points) to develop defensible and achievable limits. One

reason for this is that the control technology is relatively new, and

there were no data collected by EPA test methods prior to this

rulemaking. Therefore, the development of a quantitative standard was

not feasible or practicable. The problem was also complicated by the

numerous variations in the design and operation of paste plants.

However, the available information and engineering judgement indicated

that the best POM control technology in use for paste plants was the

dry coke scrubber, which was determined to represent MACT. For these

reasons, an equipment standard requiring the use of a dry coke scrubber

or equivalent alternative control for paste production was developed

under section 112(h) of the Act.

Comments were received from both the industry and States asking for

consideration of control techniques, including pollution prevention,

that might provide a level of control equivalent to or better than a

dry coke scrubber. After consideration, EPA decided that a streamlined

approach could be used to implement more efficiently section 112(h)(3)

of the Act, which allows the development of an alternative means of

emission limitation if it achieves an emission reduction at least

equivalent to that achieved by the design, equipment, work practice, or

operational standard. An emission limit for POM in lb/ton of paste was

developed from the limited data associated with two of the best

controlled plants in the industry. Although the limit may represent a

level of emission control more stringent than the equipment standard

that was determined to be MACT, an alternative standard in lb/ton of

paste will provide opportunity for pollution prevention measures (such

as reducing the quantity of POM used in paste production). The

alternative standard also provides the opportunity to qualify other

types of emission controls that might be developed in the future that

are more efficient than the dry coke scrubber.

The alternative limit in lb/ton does not preclude plants from

petitioning for other alternative means of emission limitation under

section 112(h)(3) of the Act based on demonstrating an equivalent or

greater emission reduction. However, it provides one method to

implement the provisions for alternative standards more efficiently. As

required in section 112(h)(4) of the Act, when EPA has sufficient data

to replace both parts of the current standard for paste production

plants with a quantitative emission limit, EPA will revise that

standard accordingly.

C. Achievability of Emission Limits

Comment: Several commenters expressed concern that the emission

limits for anode bake furnaces might not be achievable and requested

that the rule acknowledge that these limits may

[[Page 52393]]

need to be increased as more data are collected. One commenter

questioned the achievability of the POM limit for HSS potlines, and

another commenter supported the HSS limits and submitted additional

data for the MACT floor potlines to show that it had been achieved. One

commenter questioned the POM limits for VSS2 potlines because the

limits were based on data from VSS1 potlines.

Response: The data for anode bake furnaces support that the

proposed emission limits for both new and existing sources are

achievable. Opportunities for improved control other than the

installation of dry alumina scrubbers are available, and each owner or

operator should investigate these opportunities thoroughly. For

example, careful cleaning of recycled anodes to remove fluorides has

been demonstrated to reduce fluoride emissions from anode bake

furnaces. Careful control and optimization of combustion conditions

improve destruction of POM compounds and reduce POM emissions.

The EPA believes that the data show that the POM limit is

achievable for the HSS subcategory by plants using the MACT floor

technology. Note that the control technology used for the primary

system for the MACT floor plant is a dry alumina scrubber, whereas the

plant concerned about the achievability uses an electrostatic

precipitator. Improvements may be needed in the electrostatic

precipitator primary control system and in the potline's capture system

to reduce fugitive emissions to achieve the same level of control

achieved by the MACT floor plant.

The proposed POM limit for the VSS2 subcategory was based on data

from VSS1 potlines because there were no valid data available for POM

emissions from VSS2 potlines. Following proposal, POM data were

collected for the MACT floor VSS2 potline, and a commenter for the

company asked that EPA consider their data in establishing the POM

limit. The EPA analyzed the new POM data and concluded that the POM

limit for the VSS2 subcategory should be reduced from 3.7 lbs/ton to

3.6 lbs/ton. The emission test reports and EPA's analysis are

documented in the rulemaking docket. [See Docket Item IV-B-1.] The EPA

appreciates the effort of the company to perform emission testing and

to provide data that improve the technical basis of the POM limit for

VSS2 potlines.

D. Incorporation of the NSPS

Comment: Several commenters recommended that the NSPS for primary

aluminum plants (40 CFR part 60, subpart S) be removed and any

necessary provisions be incorporated into the NESHAP. These commenters

believed that the higher TF limits in the amended NSPS should be

incorporated instead of the lower limits in the original NSPS because

the amendment concluded that the original emission limits were not

achievable 100 percent of the time. In addition, the NESHAP general

provisions (40 CFR part 63, subpart A) require that control equipment

be operated and maintained in a manner consistent with good air

pollution control practices for minimizing emissions at least to the

level required by all relevant standards. Therefore, these commenters

concluded that this requirement overlaps the ``exemplary operation''

requirement of the NSPS, and by complying with the general provisions,

a source qualifies for the higher limits in the NSPS. State agency

commenters thought that the more stringent limits in the original NSPS

should be used for incorporation into the NESHAP.

Some commenters stated that the opacity requirements of the NSPS

were a monitoring provision and not an emission limit. They pointed out

that the proposed NESHAP contained more provisions than the NSPS to

ensure the control equipment was operating properly, such as monitoring

the air and alumina flow to the dry alumina scrubbers and a daily

visual inspection of the control equipment rather than only a monthly

observation of opacity, which the NSPS requires. Consequently, they

believed the opacity standard in the NSPS could be removed without any

loss of stringency. Another commenter stated that the NSPS opacity

limit was not applicable for wet emission control systems because of

interferences and observer error and recommended that facilities with

wet emission control systems be allowed to develop an alternative

opacity limit if they could demonstrate that the mass emission limit

for TF was being met. State agency commenters stated that the opacity

standard should be retained when the NSPS is incorporated into the

NESHAP.

In general, State agency commenters agreed that the NSPS could be

incorporated into the NESHAP, but only if all of the NSPS provisions

are retained. These include the lower emission limits in the original

NSPS, retention of the modification and reconstruction provisions of

part 60, and maintenance of the opacity limits.

Response: The EPA had stated in the original proposal when

requesting comments on this issue that incorporating the NSPS into the

NESHAP should result in a standard that would be no less stringent than

if both standards remained in place. Following the receipt of comments

and no indication that anyone was opposed to incorporation of the NSPS,

EPA conducted additional discussions with all stakeholders.

Representatives from each of the 14 States that have primary aluminum

reduction plants were contacted and were provided the opportunity to

discuss the issues and provide comments. Similar discussions were held

with the Aluminum Association and industry representatives, who also

provided comments.

Based on these discussions, a general consensus was reached on how

the NSPS could be incorporated into the NESHAP. First, the NSPS was

amended to allow an affected facility to comply either with the NSPS or

with the special provisions incorporated into the NESHAP. Second, the

NSPS requirements were included in a separate section of the NESHAP,

and these provisions apply only to emissions of TF. They apply only to

Soderberg potlines and prebake potlines in the CWPB2 and CWPB3

subcategories because other types of existing potlines are subject to

TF emission limits under the NESHAP that are more stringent than the

NSPS limits. Anode bake furnaces are not included because the NESHAP

limits for existing bake furnaces are equivalent to those in the NSPS,

and the NESHAP limits for new bake furnaces are much more stringent

than those in the NSPS.

The result of these discussions was general agreement that the

definitions of ``modification'' and ``reconstruction'' should be

incorporated so that any new, modified, or reconstructed potroom group

would trigger the NSPS provisions that have been included in the

NESHAP. In other words, any potroom group that would have become

subject to the NSPS because of the part 60 provisions would become

subject to the special provisions incorporated into subpart LL of part

63. This was accomplished by adding definitions for ``potroom group

modification'' and ``potroom group reconstruction'' that matched the

requirements in part 60. The modification would occur if there was an

increase in the total or overall TF emissions from the potroom group

(i.e., changes that result in a decrease in emissions in one part of

the potroom group and an increase in another part of the group are not

modifications if total emissions from the group do not increase).

The EPA decided not to incorporate only the lower NSPS limits as

suggested

[[Page 52394]]

by some commenters or only the higher limits recommended by other

commenters. Instead, both sets of limits were incorporated into the

NESHAP with the same language as that used in the amended NSPS. In

other words, the lower limits apply unless the owner or operator can

meet the exemplary operation requirements as stated in the NSPS, in

which case the upper limits would apply. This requires that the owner

or operator demonstrate that exemplary operation and maintenance

procedures were used with respect to the emission control system and

that control equipment was operating properly at the potline during the

performance test.

Additional insight into proper operation and maintenance is given

in the proposal preamble for the amended NSPS (45 FR 44203), which

lists these items as basic to good control of emissions from prebake

plants:

(1) Hood covers should fit properly and be in good repair;

(2) The hood exhaust rate should be increased for individual pots

when hood covers are removed (if there is an adjustable air damper

system);

(3) Hood covers should be replaced as soon as possible after each

potroom operation;

(4) Dust entrainment should be minimized during materials handling

operations and sweeping of the working aisles;

(5) Only tapping crucibles with functional air return systems

should be used; and

(6) The primary control system should be regularly inspected and

properly maintained.

For horizontal stud Soderberg potlines, Items (4) through (6)

apply, but Items (1) through (3) are replaced by the following because

of differences in pot design:

(1) Side and end doors should fit properly and be in good repair;

(2) The exhaust rate should be increased for individual pots when a

side or end door is open (if there is an adjustable air damper system);

and

(3) Side and end doors should be closed as soon as possible after

each potroom operation.

The following variations apply to vertical stud Soderberg potlines:

(1) An ore cover should be maintained on the pot;

(2) The collector skirt and burner should be in good repair; and

(3) Tap holes should not be opened too far in advance of the tap.

Another issue was related to the fact that the NSPS limits apply to

a potroom group, whereas the NESHAP limits apply to a potline. Because

of many variations in the configuration of potrooms and potlines in the

industry, limits for both would result in a somewhat confusing

situation of duplicative emission limits and other requirements for

certain reduction cells and unnecessary requirements associated with

monitoring, reporting, and recordkeeping for both potroom groups and

the potline. To resolve this issue, a method was devised in the NESHAP

to combine the limit for the NSPS potroom group with that for the

NESHAP potline based on the production capacity of the reduction cells

that would be subject to each set of limits. The result is a single TF

emission limit for the entire potline that maintains equivalent

stringency, and it has the additional advantage of allowing the use of

the NESHAP potline requirements for monitoring, reporting, and

recordkeeping to avoid unnecessary duplication.

The opacity issue was resolved by incorporating the 10 percent

limit for potroom groups from the NSPS into the NESHAP. However, the

provisions in part 60 that allow the development of an alternative

opacity limit when the facility demonstrates that the mass emission

limits are being met were also included in the NESHAP. The alternative

opacity limit cannot exceed 20 percent. Historically, opacity has been

measured routinely for the discharge stacks of primary control systems.

However, the EPA has no indication that the opacity of a potroom group

roof monitor has been measured using Method 9.

The EPA decided that additional provisions for anode bake furnaces

were not necessary because the NESHAP requires that existing furnaces

be controlled at levels equivalent to what the NSPS would have required

for new, modified, or reconstructed furnaces. This ensures that the

MACT floor control technology (dry alumina scrubbers) or the equivalent

will be installed on all bake furnaces to control emissions. There was

no need to incorporate the NSPS opacity limit of 20 percent for bake

furnaces because the MACT floor technology will achieve lower opacity

levels, the NESHAP monitoring requirements for the control device are

more comprehensive, there is no loss in stringency, and most States

already have general opacity limits of 20 percent for stationary point

sources.

In consolidating the two rules, the EPA decided to use the sampling

frequency and monitoring provisions of the NESHAP. They offer several

advantages over the NSPS provisions alone, there is no effect on the

relative stringency or the emission reductions achieved, and they will

reduce unnecessary monitoring, reporting, and recordkeeping. In

addition, the NESHAP requires that any new, modified, or reconstructed

potroom group be sampled for TF emissions, which is what the NSPS would

have required. Sampling can be performed effectively for the potroom

group with the addition of new monitoring equipment or the expansion or

adaptation of existing monitoring equipment in the same potline if the

sampling system is determined to be representative of the entire

potline and if the relevant regulatory authority determines that the

sampling system meets the requirements of the reference test methods.

In addition, the sampling of that potroom group may be used to

determine emissions from the total potline if they are representative

of the entire potline. To be representative of the entire potline, the

sampling system must not cover only or primarily new reduction cells,

which would be expected to have better hooding and emission control

than older cells.

E. Time Limit for Approval by the Regulatory Authority

Comment: Several industry commenters recommended that the final

rule include a time limit for regulatory authority review, approval,

and/or action on submissions. Examples include the compliance test

plan, the implementation plan for emission averaging, an application to

change control device parameter operating limits, requests for

alternative monitoring for similar potlines, requests for approval of

alternative methods for sampling and analysis, requests for reduced

sampling frequency, and requests to modify the startup, shutdown, and

malfunction plan. According to the commenters, each submission should

be given automatic approval if no action or response is taken by the

applicable regulatory authority within some time period (generally

within 30 days of receipt).

Response: The proposed rule contained provisions for a time limit

of 120 days for regulatory approval or disapproval of the

implementation plan for emission averaging, and this provision was kept

in the final rule. In addition, the general provisions in subpart A of

40 CFR part 63 allow the owner or operator to revise the startup,

shutdown, and malfunction plan without submitting it for approval. The

owner or operator must keep the previous (superseded) version and make

it available upon request for a period of 5 years after the revision.

With respect to other submissions, the rule was

[[Page 52395]]

revised to give the regulatory authority 60 days after the submission

is deemed to be complete to approve or disapprove the submission. The

60-day period applies to the facility's test plan used to determine

compliance, requests for changes in operating parameter limits,

applications for similar potline monitoring, requests for reduced

sampling frequency, and requests for alternative test methods.

F. Relationship to Other Rules

Comment: Several commenters asked about the relationship of the

NESHAP to other rules. One commenter asked for discussion of how

existing new source review (NSR) and prevention of significant

deterioration (PSD) rules affect the NESHAP, and another asked for

clarification of what TF emission limit would apply in the event of a

modification under the NSPS. Another commenter believes that conversion

and installation of equipment in order to comply with this rule should

not trigger the NSPS. The commenter requested that the language of the

preamble and the rule be changed to reflect that modifications made to

affected sources to come into compliance with the primary aluminum

NESHAP are exempted from NSPS applicability. Several industry

commenters recommended that the final rule include a provision

acknowledging that the monitoring provisions in the rule, including the

approved methods and alternatives, satisfy the monitoring provisions

under section 114 of the Act and the title I monitoring requirements

for PM emissions. Other commenters asked that certain alternatives

allowed by the rule, such as requests to change monitoring parameters

or to implement emission averaging, be identified within the rule as

``administrative changes'' to the operating permit issued under the

part 70 permit program.

Response: The NSR and PSD requirements are not changed or directly

affected by the provisions in the NESHAP. However, the NESHAP

incorporates the NSPS provisions for primary aluminum reduction plants,

which will reduce duplicative monitoring, reporting, and recordkeeping

requirements while maintaining equivalent stringency in the applicable

emission limits. In addition, the incorporation of the NSPS includes

language from part 60 that excludes from the definition of

``modification'' the addition of an emission control system that

results in the reduction of air pollutants, as the commenter suggested.

As several commenters suggested, the compliance assurance monitoring

(CAM) rule would not apply to the sources and pollutants regulated

under the NESHAP. Standards promulgated after 1990 are not subject to

the CAM under the assumption that the prescribed monitoring in such

rules would meet the requirements equivalent to those required for CAM.

The EPA determined that it is not appropriate to specify within the

NESHAP whether changes to permits should be considered administrative

or as permit modifications. This is accomplished more directly through

the permit writer, who can incorporate the alternatives allowed by the

NESHAP into the permit. By adding the NESHAP provisions to the permit,

the flexibility allowed by the NESHAP is maintained with respect to

implementation of emission averaging and other provisions. In addition,

the source may suggest to the permit writer that certain flexible

provisions are important to the source based on the compliance approach

that the source anticipates implementing.

G. Reduced Sampling Frequency

Comment: One commenter did not think there is any need for Federal

Register publication to provide public notification of approval of

reduced sampling frequency. Another commenter asked that criteria for

qualifying for reduced sampling frequency be included in the rule and

suggested using the approaches that had been used in other rules, with

reductions in the frequency after demonstrating compliance over some

period of time.

Several commenters recommended that monitoring provisions in the

final rule be expanded to allow less frequent monitoring for POM upon

demonstration of good emission control performance, as is allowed for

TF.

State agency commenters supported the concept of reduced sampling

if a facility consistently achieves compliance with an emission limit

and has low variability. However, the commenters asked that EPA specify

a minimum measure of acceptable variability for reduced sampling

frequency to ensure consistent evaluations of these requests and to

ease the burden on the regulatory authority.

Response: The EPA agrees that the provisions for qualifying for

reduced sampling can be improved by making them easier to implement and

that there is no need for publication in the Federal Register. In

addition, if they are structured properly, provisions for reduced

sampling frequency can be used to obtain control performance well below

the emission limit, which will result in additional emission

reductions.

The EPA reviewed the performance of plants that had qualified for

reduced sampling under the NSPS and also examined the average

performance, variability, and emission limits achieved by the MACT

floor plants. Based on this review, a procedure was developed that was

designed to ensure that plants that qualified for reduced sampling had

low variability, consistently met the limit, and achieved an average

long-term performance that was well below the limit. The proposed rule

was revised to allow the monthly sampling of a potline's secondary

emissions of TF to be reduced to quarterly if: (1) The overall average

after 24 consecutive months of sampling was no more than 60 percent of

the applicable limit and (2) no monthly average during the 24

consecutive months exceeded 75 percent of the applicable emission

limit.

If an exceedance occurs while under the reduced sampling frequency,

the plant must return to monthly sampling for at least 12 months. The

plant can qualify for a reduction to quarterly sampling again when: (1)

The average of all results over the most recent 24-month period is no

more than 60 percent of the limit and (2) no more than one monthly

average during the 24-month period exceeds 75 percent of the limit.

As an alternative, the facility can petition for reduced sampling

based on the statistical approach given in the EPA guidance document,

``Primary Aluminum: Statistical Analysis of Potline Fluoride Emissions

and Alternative Sampling Frequency'' (EPA-450/3-86-012, October 1986).

A copy of this document is included in the docket (docket item II-A-

10). This document also is available from the National Technical

Information Service (NTIS), 5285 Port Royal Road, Springfield, VA

22161.

Reduced sampling was not considered for POM because the sampling is

already reduced relative to sampling for TF. The rule contains

provisions for reducing TF sampling of secondary emissions from monthly

to quarterly, and it only requires quarterly sampling for POM secondary

emissions (and only annual sampling for POM from the primary control

system). The quarterly sampling is necessary to ensure compliance and

is particularly important for POM because of the potential risk

associated with the POM compounds.

H. Approval of Alcan Cassette Method (Method 14A)

Comment: Several commenters stated that the Alcan cassette

monitoring

[[Page 52396]]

method should be included as an approved method to determine compliance

for emissions monitoring, as it is approved for demonstrating similar

potlines. The final rule should also allow the method to be used in

developing correlations of emissions for alternative monitoring

devices, such as the HF CEM. Another commenter asked for the results of

the investigation of the use of Alcan cassettes as an alternative to

Methods 13 and 14, including information on accuracy, precision, and

any biases.

Response: The EPA's intent to evaluate and approve the Alcan

cassette method as an acceptable alternative to Method 14 was discussed

in the proposal preamble. Numerous comments were received supporting

the method, and no comments were received that were opposed to the

method as an alternative to Methods 13 and 14. The method had been

previously approved for sampling and analysis of TF for the NSPS, and

additional data from comparison testing (available in the docket)

confirmed it to be an acceptable alternative. Consequently, the EPA has

approved the Alcan cassette method as an alternative to Method 14 and

has included it as Method 14A in appendix A to 40 CFR part 60.

I. Estimates of Costs for Control and Monitoring

Comment: The industry commenters contended the capital costs of the

proposed rule are higher than the EPA's estimates and asked that the

estimates presented at promulgation be revised to incorporate their

higher estimates of cost. The cost estimates submitted by the Aluminum

Association included a capital cost estimate of $555 million and a

total annual cost of $126 million compared to the EPA cost estimate of

$160 million in capital and a total annual cost of $40 million. Another

commenter believes the monitoring costs estimates are low and asked for

information on the monitoring scenario that was used for costing.

Response: The limited information supplied with the industry's cost

estimates suggests that these costs may be overstated; relevant points

are discussed below. The industry's report states that the largest

component of their capital cost estimate of $555 million is for

removing existing primary control systems and installing dry alumina

scrubbers, which they say is 60 percent of the total capital cost. The

EPA worked closely with the industry to develop the MACT floor, and

based on numerous discussions with the industry, only one plant was

identified as likely to install new dry alumina scrubbers. This plant

estimated a cost of $120 million; however, this total capital

investment includes costs for controls that are not directly

attributable to the MACT standard (e.g., it includes the cost of sulfur

dioxide scrubbers that are required by the State but are not required

by the MACT standard). In addition, there is an indication that the

company's decision to install dry alumina scrubbers may not have been

made only because of the impending MACT standard but also in

consideration of State and local agency concerns. Another company that

included the capital cost of new dry scrubbers in its estimate

submitted by the Aluminum Association has subsequently confirmed that

new dry scrubbers will not be installed to meet MACT. Instead, they

will upgrade their existing control equipment at a much lower cost.

Included in the industry's estimate are costs for several potlines

that have been idled, and it has not been determined when these

potlines will operate at capacity. If they are not restarted, it is

obvious that large investments to improve emission control will not be

made.

Significant cost estimates are included in the industry's estimates

for MACT floor potlines, which are lines that by definition are already

achieving the MACT level of control (because the proposed emission

limits for MACT are based on the floor). Apparently these companies

included the routine capital and operating costs currently being

incurred or planned for the near future, probably to meet existing

State limits, and attributed this cost to MACT. The cost due to MACT is

the incremental cost above what would be spent in the absence of MACT

and should not include what is being spent to meet existing

regulations.

The few details that are available in the industry's report

indicate that some of the estimated capital investment is for

improvements or modernization of the process that is not necessarily

being done only to improve emission control. In addition, companies

will save operating expenses through improved efficiency and operation

from these improvements, and no credit (cost savings) is identified for

these improvements.

The information available for the cost of dry coke scrubbers

indicates that the industry's estimate is overstated by a factor of at

least two. The EPA estimate is based on the actual installation cost

reported by one company and was verified by another company that

obtained an actual construction cost estimate prior to installing a new

coke scrubber. The source of the industry's estimate is undocumented.

In addition, more recent information from a few plants indicates that

they may be able to improve the control efficiency of existing control

equipment without installing dry coke scrubbers. The EPA cost estimate

assumes that all plants without dry coke scrubbers will install one.

J. Exceeding an Operating Parameter Limit

Comment: Several industry commenters stated that an exceedance of

an enforceable operating parameter limit for which the owner or

operator has submitted a request for redetermination should not count

toward the six allowable exceedances or automatically constitute a

violation. Another commenter felt that exceedances should be a matter

of enforcement discretion and any mention of what would constitute a

violation should be deleted from the rule. One commenter asked for

EPA's basis in deciding that a violation has occurred only after there

have been six exceedances of a monitoring parameter (in any 6-month

reporting period).

Response: The proposal preamble discussed at length why any single

exceedance of the parametric monitoring limits should not be considered

an exceedance of the emission limit and a violation of the standard.

However, a limit was placed on the number of exceedances (six) allowed

in a 6-month period to provide incentive to correct any problems with

control devices promptly and to avoid recurring difficulties with

control devices. Consequently, any exceedance of an enforceable

operating parameter limit will count toward the six allowable

exceedances, or will constitute a violation if a source has already had

six exceedances. The fact that a facility has submitted a request for a

redetermination of its operating parameter limits is no shield against

enforcement of the existing permit limits. This is because the owner or

operator could submit requests for redetermination to avoid a violation

whenever control device monitoring indicates a problem. While the

commenter is correct in pointing out that EPA may exercise

prosecutorial discretion, such discretion is independent from the

identification of a violation.

K. Pitch Storage Tanks

Comment: Several commenters requested that the proposed rule be

clarified to indicate that pitch storage

[[Page 52397]]

tanks are not included as part of the paste production plant.

Response: Based on comments that pitch storage tanks are not a part

of the paste production operation, the EPA reexamined this issue and

determined that pitch storage tanks not located within the paste

production plant should be defined as a separate affected source. Pitch

storage tanks located within the boundaries of the paste production

plant, such as day tanks or feed tanks that manage heated pitch, are

included in the definition of paste production plant and must be

controlled as required for the paste plant. An examination of the

available data for pitch storage tanks that are not a part of the paste

production plant indicated that the MACT floor and MACT for existing

sources was no control. However, one plant was found to have installed

controls on a recently constructed pitch storage tank. In addition, the

EPA found that a new pitch storage tank planned for installation in

Canada would be installing a catalytic oxidizer to control pitch fumes

with a control efficiency of at least 95 percent. Consequently, EPA

determined that new source MACT for pitch storage tanks would require

at least 95 percent control of POM, and these provisions were added to

the final rule.

There are several types of emission control techniques that can

achieve 95 percent control or better, including combustion devices, dry

scrubbers, and carbon adsorption. A question arose about the

acceptability of vapor balancing, in which emissions displaced from the

pitch storage tank during loading are returned to the tank truck or

rail car as it is emptied. This technique would be an acceptable

alternative if the owner or operator demonstrates (to the satisfaction

of the applicable regulatory authority) that emissions from the

transport vessel are controlled when it is refilled and that POM

emissions from the pitch storage tank are ultimately controlled at 95

percent or better.

VII. Administrative Requirements

A. Docket

The docket is an organized and complete file of information

considered by the EPA in the development of a rulemaking. The docket is

a dynamic file because information is added throughout the rulemaking

development process. 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.] The official

rulemaking record, including all public comments received on the

proposed rule, is located at the address in the ADDRESSES section at

the beginning of this document.

B. 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.

Although this is a significant regulatory action OMB has waived

Executive Order 12866 review because there was no significant negative

comment on the proposed rule.

C. Enhancing the Intergovernmental Partnership Under Executive Order

12875

In compliance with Executive Order 12875, the EPA involved State

regulatory experts in the development of the rule. The EPA also

coordinated with tribal governments having an interest in the

rulemaking. State and local governments and tribal governments are not

directly affected by the rule, i.e., they are not required to purchase

control systems to meet the requirements of the rule. However, State

and local governments will be required to implement the rule; i.e.,

incorporate the rule into permits and enforce the rule. They will

collect permit fees that will be used to offset the resource burden of

implementing the rule. Comments were solicited from States and tribal

governments and have been considered in the development of the final

rule.

D. Unfunded Mandates Reform Act

Title II of the Unfunded Mandates Reform Act of 1995 (UMRA), Public

Law 104-4, establishes requirements for Federal agencies to assess the

effects of their regulatory actions on State, local, and tribal

governments and the private sector. Under section 202 of the UMRA, EPA

generally must prepare a written statement, including a cost-benefit

analysis, for proposed and final rules with ``Federal mandates'' that

may result in expenditures to State, local, and tribal governments, in

the aggregate, or to 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 EPA to identify

and consider a reasonable number of regulatory alternatives and adopt

the least costly, most cost-effective, or least burdensome alternative

that achieves the objectives of the rule. The provisions of section 205

do not apply when they are inconsistent with applicable law. Moreover,

section 205 allows EPA to adopt an alternative other than the least

costly, most cost-effective, or least burdensome alternative if the

Administrator publishes with the final rule an explanation why that

alternative was not adopted. Before EPA establishes any regulatory

requirements that may significantly or uniquely affect small

governments, including tribal governments, it must have developed under

section 203 of 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 developing 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. The total annualized cost of the final standard

is estimated at $40 million per year--well under the $100 million per

year threshold. Thus, today's rule is not subject to the requirements

of sections 202 and 205 of UMRA.

E. Regulatory Flexibility

The Regulatory Flexibility Act (RFA) generally requires an agency

to conduct

[[Page 52398]]

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 governmental jurisdictions.

The EPA has determined that it is not necessary to prepare a

regulatory flexibility analysis in connection with this final rule.

None of the 23 facilities in this industry is classified as a small

entity. The EPA has determined that this rule will not have a

significant economic impact on a substantial number of small entities.

F. Submission to Congress and the General Accounting Office

Under 5 U.S.C. 801(a)(1)(A), as added by the Small Business

Regulatory Enforcement Fairness Act of 1996, EPA submitted a report

containing this rule and other required information to the U.S. Senate,

the U.S. House of Representatives, and the Comptroller General of the

General Accounting Office prior to publication of the rule in today's

Federal Register. This rule is not a ``major rule'' as defined by 5

U.S.C. 804(2).

G. Paperwork Reduction Act

The information collection requirements for this NESHAP have been

submitted for approval to OMB under the Paperwork Reduction Act, 44

U.S.C. 3501 et seq. An Information Collection Request (ICR) document

has been prepared by the EPA (ICR No. 1767.02), and a copy may be

obtained from Sandy Farmer, OPPE Regulatory Information Division, U.S.

Environmental Protection Agency (2137), 401 M Street, S.W., Washington,

DC 20460, or by calling (202) 260-2740. The information requirements

are not effective until OMB approves them.

The information collection requirements include mandatory

notifications, records, and reports required by the NESHAP general

provisions (40 CFR part 63, subpart A). These information collection

requirements are needed to confirm the compliance status of major

sources, to identify any nonmajor sources not subject to the standards

and any new or reconstructed sources subject to the standards, to

confirm that emission control devices are being properly operated and

maintained, and to ensure that the standards are being achieved. Based

on the recorded and reported information, EPA can decide which plants,

records, or processes should be inspected. These recordkeeping and

reporting requirements are specifically authorized by section 114 of

the Act (42 U.S.C. 7414). All information submitted to the Agency for

which a claim of confidentiality is made will be safeguarded according

to Agency policies in 40 CFR part 2, subpart B. (See 41 FR 36902,

September 1, 1976; 43 FR 39999, September 28, 1978; 43 FR 42251,

September 28, 1978; and 44 FR 17674, March 23, 1979.)

The annual public reporting and recordkeeping burden for collecting

this information (averaged over the first 3 years after the effective

date of the rule) is estimated to total 52,544 hours for the 23

respondents and to average 2,300 hours per respondent (i.e., per

plant). Each respondent is required to report semiannually. The

annualized cost of monitoring equipment is estimated as $390,000 per

year, with an operation and maintenance cost of $39,000 per year

(excluding labor hours included in the previous total).

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 collecting, validating, and verifying

information; process and maintain information and disclose and provide

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.

H. Clean Air Act

The NESHAP for primary aluminum reduction plants will be reviewed 8

years from the date of promulgation. This review will include an

assessment of such factors as residual health risks, any duplication

with other air programs, the existence of alternative methods,

enforceability, improvements in air emission control technology and

health data, and the recordkeeping and reporting requirements.

List of Subjects

40 CFR Part 9

Environmental protection, Reporting and recordkeeping requirements.

40 CFR Part 60

Environmental protection, Administrative practice and procedure,

Air pollution control, Incorporation by reference.

40 CFR Part 63

Air pollution control, Hazardous substances, Incorporation by

reference, Primary aluminum reduction plants, Reporting and

recordkeeping requirements.

Dated: September 19, 1997.

Carol M. Browner,

Administrator.

For the reasons set out in the preamble, parts 9, 60, and 63 of

title 40, chapter I of the Code of Federal Regulations are amended as

follows:

PART 9--OMB APPROVALS UNDER THE PAPERWORK REDUCTION ACT

1. The authority citation for part 9 continues to read as follows:

Authority: 7 U.S.C. 135 et seq., 136-136y; 15 U.S.C. 2001, 2003,

2005, 2006, 2601-2671; 21 U.S.C. 331j, 346a, 348; 31 U.S.C. 9701; 33

U.S.C. 1251 et. seq., 1311, 1313d, 1314, 1321, 1326, 1330, 1342,

1344, 1345 (d) and (e), 1361; E.O. 11735, 38 FR 21243, 3 CFR, 1971-

1975 Comp. p. 973; 42 U.S.C. 241, 242b, 243, 246, 300f, 300g, 300g-

1, 300g-2, 300g-3, 300g-4, 300g-5, 300g-6, 300j-1, 300j-2, 300j-3,

300j-4, 300j-9, 1857 et seq., 6901-6992k, 7401-7671q, 7542, 9601-

9657, 11023, 11048.

2. In Sec. 9.1 the table is amended by adding new entries under the

indicated heading in numerical order to read as follows:

Sec. 9.1 OMB approvals under the Paperwork Reduction Act.

* * * * *

------------------------------------------------------------------------

OMB control

40 CFR citation No.

------------------------------------------------------------------------

* * * * *

National Emission Standards for Hazardous Air Pollutants for Source

Categories \3\

* * * * *

63.846(d).................................................. 2060-0360

63.847(b), (g)............................................. 2060-0360

63.848(d)(5), (e),.........................................

(f)(5)(ii), (g), (k), (m).................................. 2060-0360

63.850..................................................... 2060-0360

* * * * *

------------------------------------------------------------------------

\3\ The ICRs referenced in this section of the Table encompass the

applicable general provisions contained in 40 CFR part 63, subpart A,

which are not independent information collection requirements.

[[Page 52399]]

PART 60--STANDARDS OF PERFORMANCE FOR NEW STATIONARY SOURCES

3. The authority for part 60 continues to read as follows:

Authority: 42 U.S.C. 7401, 7411, 7413, 7414, 7416, 7429, 7601

and 7602.

Sec. 60.17 [Amended]

4. Section 60.17(a)(22) of subpart A is amended by adding the

phrase ``; Method 14A, par. 7.1'' to the end of the paragraph.

5. Section 60.190 is amended by revising paragraph (b) and adding

new paragraph (c) to read as follows:

Sec. 60.190 Applicability and designation of affected facility.

* * * * *

(b) Except as provided in paragraph (c) of this section, any

affected facility under paragraph (a) of this section that commences

construction or modification after October 23, 1974, is subject to the

requirements of this subpart.

(c) An owner or operator of an affected facility under paragraph

(a) of this section may elect to comply with the requirements of this

subpart or the requirements of subpart LL of part 63 of this chapter.

6. Appendix A to part 60 is amended by revising the appendix

heading and adding, in numerical order, Method 14A to read as follows:

Appendix A To part 60--Test Methods

* * * * *

Method 14A--Determination of Total Fluoride Emissions from Selected

Sources at Primary Aluminum Production Facilities

Note: This method does not include all the specifications (e.g.,

equipment and supplies) and procedures (e.g., sampling) essential to

its performance. Some material is incorporated by reference from

other methods in this part. Therefore, to obtain reliable results,

persons using this method should have a thorough knowledge of at

least the following additional test methods: Method 5, Methods 13A

and 13B, and Method 14 of this appendix.

1.0 Scope and Application.

1.1 Analytes.

------------------------------------------------------------------------

Analyte CAS No. Sensitivity

------------------------------------------------------------------------

Total fluorides................. None assigned..... Not determined.

Includes hydrogen fluoride...... 007664-39-3....... Not determined.

------------------------------------------------------------------------

1.2 Applicability. This method is applicable for the

determination of total fluorides (TF) emissions from sources

specified in the applicable regulation. This method was developed by

consensus with the Aluminum Association and the U.S. Environmental

Protection Agency (EPA).

2.0 Summary of Method.

2.1 Total fluorides, in the form of solid and gaseous

fluorides, are withdrawn from the ascending air stream inside of an

aluminum reduction potroom and, prior to exiting the potroom roof

monitor, into a specific cassette arrangement. The cassettes are

connected by tubing to flowmeters and a manifold system that allows

for the equal distribution of volume pulled through each cassette,

and finally to a dry gas meter. The cassettes have a specific

internal arrangement of one unaltered cellulose filter and support

pad in the first section of the cassette for solid fluoride

retention and two cellulose filters with support pads that are

impregnated with sodium formate for the chemical absorption of

gaseous fluorides in the following two sections of the cassette. A

minimum of eight cassettes shall be used for a potline and shall be

strategically located at equal intervals across the potroom roof so

as to encompass a minimum of 8 percent of the total length of the

potroom. A greater number of cassettes may be used should the

regulated facility choose to do so. The mass flow rate of pollutants

is determined with anemometers and temperature sensing devices

located immediately below the opening of the roof monitor and spaced

evenly within the cassette group.

3.0 Definitions.

3.1 Cassette. A segmented, styrene acrylonitrile cassette

configuration with three separate segments and a base, for the

purpose of this method, to capture and retain fluoride from potroom

gases.

3.2 Cassette arrangement. The cassettes, tubing, manifold

system, flowmeters, dry gas meter, and any other related equipment

associated with the actual extraction of the sample gas stream.

3.3 Cassette group. That section of the potroom roof monitor

where a distinct group of cassettes is located.

3.4 Potline. A single, discrete group of electrolytic reduction

cells electrically connected in series, in which alumina is reduced

to form aluminum.

3.5 Potroom. A building unit that houses a group of

electrolytic reduction cells in which aluminum is produced.

3.6 Potroom group. An uncontrolled potroom, a potroom that is

controlled individually, or a group of potrooms or potroom segments

ducted to a common primary control system.

3.7 Primary control system. The equipment used to capture the

gases and particulate matter generated during the reduction process

and the emission control device(s) used to remove pollutants prior

to discharge of the cleaned gas to the atmosphere.

3.8 Roof monitor. That portion of the roof of a potroom

building where gases, not captured at the cell, exit from the

potroom.

3.9 Total fluorides (TF). Elemental fluorine and all fluoride

compounds as measured by Methods 13A or 13B of this appendix or by

an approved alternative method.

4.0 Interferences and Known Limitations.

4.1 There are two principal categories of limitations that must

be addressed when using this method. The first category is sampling

bias and the second is analytical bias. Biases in sampling can occur

when there is an insufficient number of cassettes located along the

roof monitor of a potroom or if the distribution of those cassettes

is spatially unequal. Known sampling biases also can occur when

there are leaks within the cassette arrangement and if anemometers

and temperature devices are not providing accurate data. Applicable

instruments must be properly calibrated to avoid sampling bias.

Analytical biases can occur when instrumentation is not calibrated

or fails calibration and the instrument is used out of proper

calibration. Additionally, biases can occur in the laboratory if

fusion crucibles retain residual fluorides over lengthy periods of

use. This condition could result in falsely elevated fluoride

values. Maintaining a clean work environment in the laboratory is

crucial to producing accurate values.

4.2 Biases during sampling can be avoided by properly spacing

the appropriate number of cassettes along the roof monitor,

conducting leak checks of the cassette arrangement, calibrating the

dry gas meter every 30 days, verifying the accuracy of individual

flowmeters (so that there is no more than 5 percent difference in

the volume pulled between any two flowmeters), and calibrating or

replacing anemometers and temperature sensing devices as necessary

to maintain true data generation.

4.3 Analytical biases can be avoided by calibrating instruments

according to the manufacturer's specifications prior to conducting

any analyses, by performing internal and external audits of up to 10

percent of all samples analyzed, and by rotating individual

crucibles as the ``blank'' crucible to detect any potential residual

fluoride carry-over to samples. Should any contamination be

discovered in the blank crucible, the crucible shall be thoroughly

cleaned to remove any detected residual fluorides and a ``blank''

analysis conducted again to evaluate the effectiveness of the

cleaning. The crucible shall remain in service as long as no

detectable residual fluorides are present.

5.0 Safety.

5.1 This method may involve the handling of hazardous materials

in the analytical phase. This method does not purport to address all

of the potential safety hazards associated with its use. It is the

responsibility of the user to establish appropriate safety and

health practices and determine the applicability of regulatory

limitations prior to performing this test method.

5.2 Corrosive reagents. The following reagents are hazardous.

Personal protective equipment and safe procedures are useful in

preventing chemical splashes. If contact occurs, immediately flush

with copious amounts of water for at least 15 minutes. Remove

clothing under shower and

[[Page 52400]]

decontaminate. Treat residual chemical burn as thermal burn.

5.3 Sodium Hydroxide (NaOH). Causes severe damage to eyes and

skin. Inhalation causes irritation to nose, throat, and lungs.

Reacts exothermically with limited amounts of water.

5.4 Perchloric Acid (HClO4). Corrosive to eyes,

skin, nose, and throat. Provide ventilation to limit exposure. Very

strong oxidizer. Keep separate from water and oxidizable materials

to prevent vigorous evolution of heat, spontaneous combustion, or

explosion. Heat solutions containing HClO4 only in hoods

specifically designed for HClO4.

216.0 Equipment and Supplies.

6.1 Sampling.

6.1.1 Cassette arrangement. The cassette itself is a three-

piece, styrene acrylonitrile cassette unit (a Gelman Sciences

product), 37 millimeter (mm), with plastic connectors. In the first

section (the intake section), an untreated Gelman Sciences 37 mm,

0.8 micrometer (m) DM-800 metricel membrane filter and

cellulose support pad, or equivalent, is situated. In the second and

third segments of the cassette there is placed one each of Gelman

Sciences 37 mm, 5 m GLA-5000 low-ash PVC filter with a

cellulose support pad or equivalent product. Each of these two

filters and support pads shall have been immersed in a solution of

10 percent sodium formate (volume/volume in an ethyl alcohol

solution). The impregnated pads shall be placed in the cassette

segments while still wet and heated at 50 deg.C (122 deg.F) until

the pad is completely dry. It is important to check for a proper fit

of the filter and support pad to the cassette segment to ensure that

there are no areas where gases could bypass the filter. Once all of

the cassette segments have been prepared, the cassette shall be

assembled and a plastic plug shall be inserted into the exhaust hole

of the cassette. Prior to placing the cassette into service, the

space between each segment shall be taped with an appropriately

durable tape to prevent the infiltration of gases through the points

of connection, and an aluminum nozzle shall be inserted into the

intake hole of the cassette. The aluminum nozzle shall have a short

section of tubing placed over the opening of the nozzle, with the

tubing plugged to prevent dust from entering the nozzle and to

prepare the nozzle for the cassette arrangement leak check. An

alternate nozzle type can be used if historical results or

scientific demonstration of applicability can be shown.

6.1.2 Anemometers and temperature sensing devices. To calculate

the mass flow rate of TF from the roof monitor under standard

conditions, anemometers that meet the specifications in section

2.1.1 in Method 14 of this appendix or an equivalent device yielding

equivalent information shall be used. A recording mechanism capable

of accurately recording the exit gas temperature at least every 2

hours shall be used.

6.1.3 Barometer. To correct the volumetric flow from the

potline roof monitor to standard conditions, a mercury (Hg),

aneroid, or other barometer capable of measuring atmospheric

pressure to within 2.5 mm [0.1 inch (in)] Hg shall be used.

Note: The barometric reading may be obtained from a nearby

National Weather Service Station. In this case, the station value

(which is absolute barometric pressure) shall be requested and an

adjustment for elevation differences between the weather station and

the sampling point shall be made at a rate of minus 2.5 mm (0.1 in)

Hg per 30 meters (m) [100 feet (ft)] elevation increase or plus 2.5

mm (0.1 in) Hg per 30 m (100 ft) elevation decrease.

6.2 Sample recovery.

6.2.1 Hot plate.

6.2.2 Muffle furnace.

6.2.3 Nickel crucible.

6.2.4 Stirring rod. Teflon'.

6.2.5 Volumetric flask. 50-milliliter (ml).

6.2.6 Plastic vial. 50-ml.

6.3 Analysis.

6.3.1 Primary analytical method. An automated analyzer having

the following components or equivalent: a multichannel proportioning

pump, multiposition sampler, voltage stabilizer, colorimeter,

instrument recording device, microdistillation apparatus, flexible

Teflon heating bath, vacuum pump, pulse suppressers and

an air flow system.

6.3.2 Secondary analytical method. Specific Ion Electrode

(SIE).

7.0 Reagents and Standards.

7.1 Water. Deionized distilled to conform to ASTM Specification

D 1193-77, Type 3 (incorporated by reference in Sec. 60.17(a)(22) of

this part). The KMnO4 test for oxidizable organic matter

may be omitted when high concentrations of organic matter are not

expected to be present.

7.2 Calcium oxide.

7.3 Sodium hydroxide (NaOH). Pellets.

7.4 Perchloric acid (HClO4). Mix 1:1 with water.

Sulfuric acid (H2SO4) may be used in place of

HClO4.

7.5 Audit samples. The audit samples discussed in section 9.1

shall be prepared from reagent grade, water soluble stock reagents,

or purchased as an aqueous solution from a commercial supplier. If

the audit stock solution is purchased from a commercial supplier,

the standard solution must be accompanied by a certificate of

analysis or an equivalent proof of fluoride concentration.

8.0 Sample Collection and Analysis.

8.1 Preparing cassette arrangement for sampling. The cassettes

are initially connected to flexible tubing. The tubing is connected

to flowmeters and a manifold system. The manifold system is

connected to a dry gas meter (Research Appliance Company model

201009 or equivalent). The length of tubing is managed by

pneumatically or electrically operated hoists located in the roof

monitor, and the travel of the tubing is controlled by encasing the

tubing in aluminum conduit. The tubing is lowered for cassette

insertion by operating a control box at floor level. Once the

cassette has been securely inserted into the tubing and the leak

check performed, the tubing and cassette are raised to the roof

monitor level using the floor level control box. Arrangements

similar to the one described are acceptable if the scientific sample

collection principles are followed.

8.2 Test run sampling period. A test run shall comprise a

minimum of a 24-hour sampling event encompassing at least eight

cassettes per potline (or four cassettes per potroom group). Monthly

compliance shall be based on three test runs during the month. Test

runs of greater than 24 hours are allowed; however, three such runs

shall be conducted during the month.

8.3 Leak-check procedures.

8.3.1 Pretest leak check. A pretest leak-check is recommended;

however, it is not required. To perform a pretest leak-check after

the cassettes have been inserted into the tubing, isolate the

cassette to be leak-checked by turning the valves on the manifold to

stop all flows to the other sampling points connected to the

manifold and meter. The cassette, with the plugged tubing section

securing the intake of the nozzle, is subjected to the highest

vacuum expected during the run. If no leaks are detected, the tubing

plug can be briefly removed as the dry gas meter is rapidly turned

off.

8.3.2 Post-test leak check. A leak check is required at the

conclusion of each test run for each cassette. The leak check shall

be performed in accordance with the procedure outlined in section

8.3.1 of this method except that it shall be performed at a vacuum

greater than the maximum vacuum reached during the test run. If the

leakage rate is found to be no greater than 4 percent of the average

sampling rate, the results are acceptable. If the leakage rate is

greater than 4 percent of the average sampling rate, either record

the leakage rate and correct the sampling volume as discussed in

section 12.4 of this method or void the test run if the minimum

number of cassettes were used. If the number of cassettes used was

greater than the minimum required, discard the leaking cassette and

use the remaining cassettes for the emission determination.

8.3.3 Anemometers and temperature sensing device placement.

Install the recording mechanism to record the exit gas temperature.

Anemometers shall be installed as required in section 6.1.2 of

Method 14 of this appendix, except replace the word ``manifold''

with ``cassette group'' in section 6.1.2.3. These two different

instruments shall be located near each other along the roof monitor.

See conceptual configurations in Figures 14A-1, 14A-2, and 14A-3 of

this method. Fewer temperature devices than anemometers may be used

if at least one temperature device is located within the span of the

cassette group. Other anemometer location siting scenarios may be

acceptable as long as the exit velocity of the roof monitor gases is

representative of the entire section of the potline being sampled.

8.4 Sampling. The actual sample run shall begin with the

removal of the tubing and plug from the cassette nozzle. Each

cassette is then raised to the roof monitor area, the dry gas meter

is turned on, and the flowmeters are set to the calibration point,

which allows an equal volume of sampled gas to enter each cassette.

The dry gas meter shall be set to a range suitable for the specific

potroom type being sampled that will yield valid data known from

previous experience or a range determined by the use of the

calculation in section 12 of this method.

[[Page 52401]]

Parameters related to the test run that shall be recorded, either

during the test run or after the test run if recording devices are

used, include: anemometer data, roof monitor exit gas temperature,

dry gas meter temperature, dry gas meter volume, and barometric

pressure. At the conclusion of the test run, the cassettes shall be

lowered, the dry gas meter turned off, and the volume registered on

the dry gas meter recorded. The post-test leak check procedures

described in section 8.3.2 of this method shall be performed. All

data relevant to the test shall be recorded on a field data sheet

and maintained on file.

8.5 Sample recovery.

8.5.1 The cassettes shall be brought to the laboratory with the

intake nozzle contents protected with the section of plugged tubing

previously described. The exterior of cassettes shall carefully be

wiped free of any dust or debris, making sure that any falling dust

or debris does not present a potential laboratory contamination

problem.

8.5.2 Carefully remove all tape from the cassettes and remove

the initial filter, support pad, and all loose solids from the first

(intake) section of the cassette. Fold the filter and support pad

several times and, along with all loose solids removed from the

interior of the first section of the cassette, place them into a

nickel crucible. Using water, wash the interior of the nozzle into

the same nickel crucible. Add 0.1 gram (g) [0.1

milligram (mg)] of calcium oxide and a sufficient amount of water to

make a loose slurry. Mix the contents of the crucible thoroughly

with a Teflon'' stirring rod. After rinsing any adhering residue

from the stirring rod back into the crucible, place the crucible on

a hot plate or in a muffle furnace until all liquid is evaporated

and allow the mixture to gradually char for 1 hour.

8.5.3 Transfer the crucible to a cold muffle furnace and ash at

600 deg.C (1,112 deg.F). Remove the crucible after the ashing phase

and, after the crucible cools, add 3.0 g (0.1 g) of NaOH

pellets. Place this mixture in a muffle furnace at 600 deg.C

(1,112 deg.F) for 3 minutes. Remove the crucible and roll the melt

so as to reach all of the ash with the molten NaOH. Let the melt

cool to room temperature. Add 10 to 15 ml of water to the crucible

and place it on a hot plate at a low temperature setting until the

melt is soft or suspended. Transfer the contents of the crucible to

a 50-ml volumetric flask. Rinse the crucible with 20 ml of 1:1

perchloric acid or 20 ml of 1:1 sulfuric acid in two (2) 10 ml

portions. Pour the acid rinse slowly into the volumetric flask and

swirl the flask after each addition. Cool to room temperature. The

product of this procedure is particulate fluorides.

8.5.4 Gaseous fluorides can be isolated for analysis by

folding the gaseous fluoride filters and support pads to

approximately \1/4\ of their original size and placing them in a 50-

ml plastic vial. To the vial add exactly 10 ml of water and leach

the sample for a minimum of 1 hour. The leachate from this process

yields the gaseous fluorides for analysis.

9.0 Quality Control.

9.1 Laboratory auditing. Laboratory audits of specific and

known concentrations of fluoride shall be submitted to the

laboratory with each group of samples submitted for analysis. An

auditor shall prepare and present the audit samples as a ``blind''

evaluation of laboratory performance with each group of samples

submitted to the laboratory. The audits shall be prepared to

represent concentrations of fluoride that could be expected to be in

the low, medium and high range of actual results. Average recoveries

of all three audits must equal 90 to 110 percent for acceptable

results; otherwise, the laboratory must investigate procedures and

instruments for potential problems.

Note: The analytical procedure allows for the analysis of

individual or combined filters and pads from the cassettes provided

that equal volumes (10 percent) are sampled through each

cassette.

10.0 Calibrations.

10.1 Equipment evaluations. To ensure the integrity of this

method, periodic calibrations and equipment replacements are

necessary.

10.1.1 Metering system. At 30-day intervals the metering system

shall be calibrated. Connect the metering system inlet to the outlet

of a wet test meter that is accurate to 1 percent. Refer to Figure

5-4 of Method 5 of this appendix. The wet-test meter shall have a

capacity of 30 liters/revolution [1 cubic foot (ft\3\)/revolution].

A spirometer of 400 liters (14 ft\3\) or more capacity, or

equivalent, may be used for calibration; however, a wet-test meter

is usually more practical. The wet-test meter shall be periodically

tested with a spirometer or a liquid displacement meter to ensure

the accuracy. Spirometers or wet-test meters of other sizes may be

used, provided that the specified accuracies of the procedure are

maintained. Run the metering system pump for about 15 min. with the

orifice manometer indicating a median reading as expected in field

use to allow the pump to warm up and to thoroughly wet the interior

of the wet-test meter. Then, at each of a minimum of three orifice

manometer settings, pass an exact quantity of gas through the wet-

test meter and record the volume indicated by the dry gas meter.

Also record the barometric pressure, the temperatures of the wet

test meter, the inlet temperatures of the dry gas meter, and the

temperatures of the outlet of the dry gas meter. Record all

calibration data on a form similar to the one shown in Figure 5-5 of

Method 5 of this appendix and calculate Y, the dry gas meter

calibration factor, and H@, the orifice

calibration factor at each orifice setting. Allowable tolerances for

Y and H@ are given in Figure 5-6 of Method 5 of

this appendix.

10.1.2 Estimating volumes for initial test runs. For a

facility's initial test runs, the regulated facility must have a

target or desired volume of gases to be sampled and a target range

of volumes to use during the calibration of the dry gas meter. Use

Equations 14A-1 and 14A-2 in section 12 of this method to derive the

target dry gas meter volume (Fv) for these purposes.

10.1.3 Calibration of anemometers and temperature sensing

devices. If the standard anemometers in Method 14 of this appendix

are used, the calibration and integrity evaluations in sections

10.3.1.1 through 10.3.1.3 of Method 14 of this appendix shall be

used as well as the recording device described in section 2.1.3 of

Method 14. The calibrations or complete change-outs of anemometers

shall take place at a minimum of once per year. The temperature

sensing and recording devices shall be calibrated according to the

manufacturer's specifications.

10.1.4 Calibration of flowmeters. The calibration of flowmeters

is necessary to ensure that an equal volume of sampled gas is

entering each of the individual cassettes and that no large

differences, which could possibly bias the sample, exist between the

cassettes.

10.1.4.1 Variable area, 65 mm flowmeters or equivalent shall be

used. These flowmeters can be mounted on a common base for

convenience. These flowmeters shall be calibrated by attaching a

prepared cassette, complete with filters and pads, to the flowmeter

and then to the system manifold. This manifold is an aluminum

cylinder with valved inlets for connections to the flowmeters/

cassettes and one outlet to a dry gas meter. The connection is then

made to the wet-test meter and finally to a dry gas meter. All

connections are made with tubing.

10.1.4.2 Turn the dry gas meter on for 15 min. in preparation

for the calibration. Turn the dry gas meter off and plug the intake

hole of the cassette. Turn the dry gas meter back on to evaluate the

entire system for leaks. If the dry gas meter shows a leakage rate

of less than 0.02 ft3/min at 10 in. of Hg vacuum as noted

on the dry gas meter, the system is acceptable to further

calibration.

10.1.4.3 With the dry gas meter turned on and the flow

indicator ball at a selected flow rate, record the exact amount of

gas pulled through the flowmeter by taking measurements from the wet

test meter after exactly 10 min. Record the room temperature and

barometric pressure. Conduct this test for all flowmeters in the

system with all flowmeters set at the same indicator ball reading.

When all flowmeters have gone through the procedure above, correct

the volume pulled through each flowmeter to standard conditions. The

acceptable difference between the highest and lowest flowmeter rate

is 5 percent. Should one or more flowmeters be outside of the

acceptable limit of 5 percent, repeat the calibration procedure at a

lower or higher indicator ball reading until all flowmeters show no

more than 5 percent difference among them.

10.1.4.4 This flowmeter calibration shall be conducted at least

once per year.

10.1.5 Miscellaneous equipment calibrations. Miscellaneous

equipment used such as an automatic recorder/ printer used to

measure dry gas meter temperatures shall be calibrated according to

the manufacturer's specifications in order to maintain the accuracy

of the equipment.

11.0 Analytical Procedure.

11.1 The preferred primary analytical determination of the

individual isolated samples or the combined particulate and gaseous

samples shall be performed by an automated methodology. The

analytical

[[Page 52402]]

method for this technology shall be based on the manufacturer's

instructions for equipment operation and shall also include the

analysis of five standards with concentrations in the expected range

of the actual samples. The results of the analysis of the five

standards shall have a coefficient of correlation of at least 0.99.

A check standard shall be analyzed as the last sample of the group

to determine if instrument drift has occurred. The acceptable result

for the check standard is 95 to 105 percent of the standard's true

value.

11.2 The secondary analytical method shall be by specific ion

electrode if the samples are distilled or if a TISAB IV buffer is

used to eliminate aluminum interferences. Five standards with

concentrations in the expected range of the actual samples shall be

analyzed, and a coefficient of correlation of at least 0.99 is the

minimum acceptable limit for linearity. An exception for this limit

for linearity is a condition when low-level standards in the range

of 0.01 to 0.48 g fluoride/ml are analyzed. In this

situation, a minimum coefficient of correlation of 0.97 is required.

TISAB II shall be used for low-level analyses.

12.0 Data Analysis and Calculations.

12.1 Carry out calculations, retaining at least one extra

decimal point beyond that of the acquired data. Round off values

after the final calculation. Other forms of calculations may be used

as long as they give equivalent results.

12.2 Estimating volumes for initial test runs.

[GRAPHIC] [TIFF OMITTED] TR07OC97.000

Where

Fv = Desired volume of dry gas to be sampled, ft\3\.

Fd = Desired or analytically optimum mass of TF per

cassette, micrograms of TF per cassette (g/cassette).

X = Number of cassettes used.

Fe = Typical concentration of TF in emissions to be

sampled, g/ft \3\, calculated from Equation 14A-2.

[GRAPHIC] [TIFF OMITTED] TR07OC97.001

Where

Re = Typical emission rate from the facility, pounds of

TF per ton (lb/ton) of aluminum.

Rp = Typical production rate of the facility, tons of

aluminum per minute (ton/min).

Vr = Typical exit velocity of the roof monitor gases,

feet per minute (ft/min).

Ar=Open area of the roof monitor, square feet

(ft2).

12.2.1 Example calculation. Assume that the typical emission rate

(Re) is 1.0 lb TF/ton of aluminum, the typical roof vent gas

exit velocity (Vr) is 250 ft/min, the typical production

rate (Rp) is 0.10 ton/min, the known open area for the roof

monitor (Ar) is 8,700 ft2, and the desired

(analytically optimum) mass of TF per cassette is 1,500 g.

First calculate the concentration of TF per cassette (Fe) in

g/ft3 using Equation 14A-2. Then calculate the

desired volume of gas to be sampled (Fv) using Equation 14A-

1.

[GRAPHIC] [TIFF OMITTED] TR07OC97.002

[[Page 52403]]

[GRAPHIC] [TIFF OMITTED] TR07OC97.003

This is a total of 575.40 ft3 for eight cassettes or

71.925 ft3/cassette.

12.3 Calculations of TF emissions from field and laboratory

data that would yield a production related emission rate can be

calculated as follows:

12.3.1 Obtain a standard cubic feet (scf) value for the volume

pulled through the dry gas meter for all cassettes by using the

field and calibration data and Equation 5-1 of Method 5 of this

appendix.

12.3.2 Derive the average quantity of TF per cassette (in

g TF/cassette) by adding all laboratory data for all

cassettes and dividing this value by the total number of cassettes

used. Divide this average TF value by the corrected dry gas meter

volume for each cassette; this value then becomes TFstd

(g/ft3).

12.3.3 Calculate the production-based emission rate

(Re) in lb/ton using Equation 14A-5.

[GRAPHIC] [TIFF OMITTED] TR07OC97.004

12.3.4 As an example calculation, assume eight cassettes

located in a potline were used to sample for 72 hours during the

run. The analysis of all eight cassettes yielded a total of 3,000

g of TF. The dry gas meter volume was corrected to yield a

total of 75 scf per cassette, which yields a value for

TFstd of 3,000/75=5 g/ft3. The open

area of the roof monitor for the potline (Ar) is 17,400

ft2. The exit velocity of the roof monitor gases

(Vr) is 250 ft/min. The production rate of aluminum over

the previous 720 hours was 5,000 tons, which is 6.94 tons/hr or

0.116 ton/min (Rp). Substituting these values into

Equation 14A-5 yields:

[GRAPHIC] [TIFF OMITTED] TR07OC97.005

12.4 Corrections to volumes due to leakage. Should the post-

test leak check leakage rate exceed 4 percent as described in

section 8.3.2 of this method, correct the volume as detailed in Case

I in section 6.3 of Method 5 of this appendix.

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[GRAPHIC] [TIFF OMITTED] TR07OC97.021

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[GRAPHIC] [TIFF OMITTED] TR07OC97.022

BILLING CODE 6560-50-L

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* * * * *

PART 63--NATIONAL EMISSION STANDARDS FOR HAZARDOUS AIR POLLUTANTS

FOR SOURCE CATEGORIES

7. The authority citation for part 63 continues to read as follows:

Authority: 42 U.S.C. 7401 et seq.

8. Part 63 is amended by adding subpart LL to read as follows:

Subpart LL--National Emission Standards for Hazardous Air Pollutants

for Primary Aluminum Reduction Plants

Sec.

63.840 Applicability.

63.841 Incorporation by reference.

63.842 Definitions.

63.843 Emission limits for existing sources.

63.844 Emission limits for new or reconstructed sources.

63.845 Incorporation of new source performance standards for

potroom groups.

63.846 Emission averaging.

63.847 Compliance provisions.

63.848 Emission monitoring requirements.

63.849 Test methods and procedures.

63.850 Notification, reporting, and recordkeeping requirements.

63.851 Regulatory authority review procedures.

63.852 Applicability of general provisions.

63.853 Delegation of authority.

63.854-63.859 [Reserved]

Table 1 to Subpart LL--Potline TF Limits for Emission Averaging

Table 2 to Subpart LL--Potline POM Limits for Emission Averaging

Table 3 to Subpart LL--Anode Bake Furnace Limits for Emission

Averaging

Appendix A to Subpart LL--Applicability of General Provisions (40

CFR Part 63, Subpart A) to Subpart LL

Subpart LL--National Emission Standards for Hazardous Air

Pollutants for Primary Aluminum Reduction Plants

Sec. 63.840 Applicability.

(a) Except as provided in paragraph (b) of this section, the

requirements of this subpart apply to the owner or operator of each new

pitch storage tank and new or existing potline, paste production plant,

or anode bake furnace associated with primary aluminum production and

located at a major source as defined in Sec. 63.2.

(b) The requirements of this subpart do not apply to any existing

anode bake furnace that is not located on the same site as a primary

aluminum reduction plant. The owner or operator shall comply with the

State MACT determination established by the applicable regulatory

authority.

(c) An owner or operator of an affected facility (potroom group or

anode bake furnace) under Sec. 60.190 of this chapter may elect to

comply with either the requirements of Sec. 63.845 of this subpart or

the requirements of subpart S of part 60 of this chapter.

Sec. 63.841 Incorporation by reference.

(a) The following material is incorporated by reference in the

corresponding sections noted. This incorporation by reference was

approved by the Director of the Federal Register on October 7, 1997, in

accordance with 5 U.S.C. 552(a) and 1 CFR part 51. These materials are

incorporated as they exist on the date of approval, and notice of any

change in the materials will be published in the Federal Register.

Revisions to ``Industrial Ventilation: A Manual of Recommended

Practice'' (22nd ed.) are applicable only after publication of a

document in the Federal Register to amend subpart LL to require use of

the new information.

(1) Chapter 3, ``Local Exhaust Hoods'' and Chapter 5, ``Exhaust

System Design Procedure'' of ``Industrial Ventilation: A Manual of

Recommended Practice,'' American Conference of Governmental Industrial

Hygienists, 22nd edition, 1995, IBR approved for Secs. 63.843(b) and

63.844(b); and

(2) ASTM D 2986-95A, Standard Practice for Evaluation of Air Assay

Media by the Monodisperse DOP (Dioctyl Phthalate) Smoke Test, IBR

approved for section 7.1.1 of Method 315 in appendix A to this part.

(b) The materials incorporated by reference are available for

inspection at the Office of the Federal Register, 800 North Capitol

Street NW., Suite 700, 7th Floor, Washington, DC, and at the Air and

Radiation Docket Center, U.S. EPA, 401 M Street, SW., Washington, DC.

The materials also are available for purchase from one of the following

addresses:

(1) Customer Service Department, American Conference of

Governmental Industrial Hygienists (ACGIH), 1330 Kemper Meadow Drive,

Cincinnati, Ohio 45240, telephone number (513) 742-2020; or

(2) American Society for Testing and Materials, 100 Bar Harbour

Drive, West Conshohocken, Pennsylvania 19428, telephone number (610)

832-9500.

Sec. 63.842 Definitions.

Terms used in this subpart are defined in the Clean Air Act as

amended (the Act), in Sec. 63.2, or in this section as follows:

Anode bake furnace means an oven in which the formed green anodes

are baked for use in a prebake process. This definition includes

multiple anode bake furnaces controlled by a common control device

(bake furnaces controlled by a common control device are considered to

be one source).

Center-worked prebake (CWPB) process means a method of primary

aluminum reduction using the prebake process in which the alumina feed

is added down the center of the reduction cell.

Center-worked prebake one (CWPB1) means all existing center-worked

prebake potlines not defined as center-worked prebake two (CWPB2) or

center-worked prebake three (CWPB3) potlines.

Center-worked prebake two (CWPB2) means all existing center-worked

prebake potlines located at Alcoa in Rockdale, Texas; Kaiser Aluminum

in Mead, Washington; Ormet Corporation in Hannibal, Ohio; Ravenswood

Aluminum in Ravenswood, West Virginia; Reynolds Metals in Troutdale,

Oregon; and Vanalco Aluminum in Vancouver, Washington.

Center-worked prebake three (CWPB3) means all existing center-

worked prebake potlines that produce very high purity aluminum, have a

wet scrubber for the primary control system, and are located at the NSA

primary aluminum plant in Hawesville, Kentucky.

Continuous 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 process or control system

parameters.

Horizontal stud Soderberg (HSS) process means a method of primary

aluminum reduction using the Soderberg process in which the electrical

current is introduced to the anode by steel rods (studs) inserted into

the side of a monolithic anode.

Modified potroom group means an existing potroom group to which any

physical change in, or change in the method of operation of, results in

an increase in the amount of total fluoride emitted into the atmosphere

by that potroom group.

Paste production plant means the processes whereby calcined

petroleum coke, coal tar pitch (hard or liquid), and/or other materials

are mixed, transferred, and formed into briquettes or paste for

vertical stud Soderberg (VSS) and HSS processes or into green anodes

for a prebake process. This definition includes all operations from

initial mixing to final forming (i.e., briquettes, paste, green anodes)

within the paste plant, including conveyors and units managing heated

liquid pitch.

Pitch storage tank means any fixed roof tank that is used to store

liquid

[[Page 52408]]

pitch that is not part of the paste production plant.

Polycyclic organic matter (POM) means organic matter extractable by

methylene chloride as determined by Method 315 in appendix A to this

part or by an approved alternative method.

Potline means a single, discrete group of electrolytic reduction

cells electrically connected in series, in which alumina is reduced to

form aluminum.

Potroom means a building unit that houses a group of electrolytic

cells in which aluminum is produced.

Potroom group means an uncontrolled potroom, a potroom that is

controlled individually, or a group of potrooms or potroom segments

ducted to a common control system.

Prebake process means a method of primary aluminum reduction that

uses an anode that was baked in an anode bake furnace, which is

introduced into the top of the reduction cell and consumed as part of

the reduction process.

Primary aluminum reduction plant means any facility manufacturing

aluminum by electrolytic reduction.

Primary control system means the equipment used to capture the

gases and particulate matter evacuated directly from the reduction cell

and the emission control device(s) used to remove pollutants prior to

discharge of the cleaned gas to the atmosphere. A roof scrubber is not

part of the primary control system.

Primary emissions means the emissions discharged from the primary

control system.

Reconstructed potroom group means an existing potroom group for

which the components are replaced to such an extent that the fixed

capital cost of the new components exceeds 50 percent of the fixed

capital cost that would be required to construct a comparable entirely

new potroom group, and for which it is technologically and economically

feasible to meet the applicable emission limits for total fluoride set

forth in this subpart.

Reconstruction means the replacement of components of a source to

such an extent that:

(1) All of the major components of the source are replaced (for

example, the major components of a potline include the raw material

handling system, reduction cells, superstructure, hooding, ductwork,

etc.); and

(2) It is technologically and economically feasible for the

reconstructed source to meet the standards for new sources established

in this subpart.

Roof monitor means that portion of the roof of a potroom building

where gases not captured at the cell exit from the potroom.

Secondary emissions means the fugitive emissions that are not

captured and controlled by the primary control system and that escape

through the roof monitor or through roof scrubbers.

Side-worked prebake (SWPB) process means a method of primary

aluminum reduction using the prebake process, in which the alumina is

added along the sides of the reduction cell.

Soderberg process means a method of primary aluminum reduction in

which the anode paste mixture is baked in the reduction pot by the heat

resulting from the electrolytic process.

Total fluorides (TF) means elemental fluorine and all fluoride

compounds as measured by Methods 13A or 13B in appendix A to part 60 of

this chapter or by an approved alternative method.

Vertical stud Soderberg (VSS) process means a method of primary

aluminum reduction using the Soderberg process, in which the electrical

current is introduced to the anode by steel rods (studs) inserted into

the top of a monolithic anode.

Vertical stud Soderberg one (VSS1) means all existing vertical stud

Soderberg potlines located either at Northwest Aluminum in The Dalles,

Oregon, or at Goldendale Aluminum in Goldendale, Washington.

Vertical stud Soderberg two (VSS2) means all existing vertical stud

Soderberg potlines located at Columbia Falls Aluminum in Columbia

Falls, Montana.

Sec. 63.843 Emission limits for existing sources.

(a) Potlines. The owner or operator shall not discharge or cause to

be discharged into the atmosphere any emissions of TF or POM in excess

of the applicable limits in paragraphs (a)(1) and (a)(2) of this

section.

(1) TF limits. Emissions of TF shall not exceed:

(i) 0.95 kg/Mg (1.9 lb/ton) of aluminum produced for each CWPB1

potline;

(ii) 1.5 kg/Mg (3.0 lb/ton) of aluminum produced for each CWPB2

potline;

(iii) 1.25 kg/Mg (2.5 lb/ton) of aluminum produced for each CWPB3

potline;

(iv) 0.8 kg/Mg (1.6 lb/ton) of aluminum produced for each SWPB

potline;

(v) 1.1 kg/Mg (2.2 lb/ton) of aluminum produced for each VSS1

potline;

(vi) 1.35 kg/Mg (2.7 lb/ton) of aluminum produced for each VSS2

potline; and

(vii) 1.35 kg/Mg (2.7 lb/ton) of aluminum produced for each HSS

potline.

(2) POM limits. Emissions of POM shall not exceed:

(i) 2.35 kg/Mg (4.7 lb/ton) of aluminum produced for each HSS

potline;

(ii) 1.2 kg/Mg (2.4 lb/ton) of aluminum produced for each VSS1

potline; and

(iii) 1.8 kg/Mg (3.6 lb/ton) of aluminum produced for each VSS2

potline.

(3) Change in subcategory. Any potline, other than a reconstructed

potline, that is changed such that its applicable subcategory also

changes shall meet the applicable emission limit in this subpart for

the original subcategory or the new subcategory, whichever is more

stringent.

(b) Paste production plants. The owner or operator shall install,

operate, and maintain equipment to capture and control POM emissions

from each paste production plant.

(1) The emission capture system shall be installed and operated to

meet the generally accepted engineering standards for minimum exhaust

rates as published by the American Conference of Governmental

Industrial Hygienists in Chapters 3 and 5 of ``Industrial Ventilation:

A Handbook of Recommended Practice'' (incorporated by reference in

Sec. 63.841 of this part); and

(2) Captured emissions shall be routed through a closed system to a

dry coke scrubber; or

(3) The owner or operator may submit a written request for use of

an alternative control device to the applicable regulatory authority

for review and approval. The request shall contain information and data

demonstrating that the alternative control device achieves POM

emissions less than 0.011 lb/ton of paste for plants with continuous

mixers or POM emissions less than 0.024 lb/ton of paste for plants with

batch mixers. The POM emission rate shall be determined by sampling

using Method 315 in appendix A to this part.

(c) Anode bake furnaces. The owner or operator shall not discharge

or cause to be discharged into the atmosphere any emissions of TF or

POM in excess of the limits in paragraphs (c)(1) and (c)(2) of this

section.

(1) TF limit. Emissions of TF shall not exceed 0.10 kg/Mg (0.20 lb/

ton) of green anode; and

(2) POM limit. Emissions of POM shall not exceed 0.09 kg/Mg (0.18

lb/ton) of green anode.

[[Page 52409]]

Sec. 63.844 Emission limits for new or reconstructed sources.

(a) Potlines. The owner or operator shall not discharge or cause to

be discharged into the atmosphere any emissions of TF or POM in excess

of the limits in paragraphs (a)(1) and (a)(2) of this section.

(1) TF limit. Emissions of TF shall not exceed 0.6 kg/Mg (1.2 lb/

ton) of aluminum produced; and

(2) POM limit. Emissions of POM from Soderberg potlines shall not

exceed 0.32 kg/Mg (0.63 lb/ton) of aluminum produced.

(b) Paste production plants. The owner or operator shall meet the

requirements in Sec. 63.843(b) for existing paste production plants.

(c) Anode bake furnaces. The owner or operator shall not discharge

or cause to be discharged into the atmosphere any emissions of TF or

POM in excess of the limits in paragraphs (c)(1) and (c)(2) of this

section.

(1) TF limit. Emissions of TF shall not exceed 0.01 kg/Mg (0.02 lb/

ton) of green anode; and

(2) POM limit. Emissions of POM shall not exceed 0.025 kg/Mg (0.05

lb/ton) of green anode.

(d) Pitch storage tanks. Each pitch storage tank shall be equipped

with an emission control system designed and operated to reduce inlet

emissions of POM by 95 percent or greater.

Sec. 63.845 Incorporation of new source performance standards for

potroom groups.

(a) Applicability. The provisions in paragraphs (a) through (i) of

this section shall apply to any Soderberg, CWPB2, and CWPB3 potline

that adds a new potroom group to an existing potline or that is

associated with a potroom group that meets the definition of ``modified

potroom group'' or ``reconstructed potroom group.''

(1) The following shall not, by themselves, be considered to result

in a potroom group modification:

(i) Maintenance, repair, and replacement that the applicable

regulatory authority determines to be routine for the potroom group;

(ii) An increase in production rate of an existing potroom group,

if that increase can be accomplished without a capital expenditure on

that potroom group;

(iii) An increase in the hours of operation;

(iv) Use of an alternative fuel or raw material if, prior to the

effective date of this subpart, the existing potroom group was designed

to accommodate that alternative use;

(v) The addition or use of any system or device whose primary

function is the reduction of air pollutants, except when an emission

control system is removed or is replaced by a system that the

applicable regulatory authority determines to be less environmentally

beneficial; and

(vi) The relocation or change in ownership of an existing potroom

group.

(2) The provisions in paragraphs (a)(2)(i) through (a)(2)(iv) of

this section apply when the applicable regulatory authority must

determine if a potroom group meets the definition of reconstructed

potroom group.

(i) ``Fixed capital cost'' means the capital needed to provide all

the depreciable components.

(ii) If an owner or operator of an existing potroom group proposes

to replace components, and the fixed capital cost of the new components

exceeds 50 percent of the fixed capital cost that would be required to

construct a comparable entirely new potroom group, he/she shall notify

the applicable regulatory authority of the proposed replacements. The

notice must be postmarked 60 days (or as soon as practicable) before

construction of the replacements is commenced and must include the

following information:

(A) Name and address of the owner or operator;

(B) The location of the existing potroom group;

(C) A brief description of the existing potroom group and the

components that are to be replaced;

(D) A description of the existing air pollution control equipment

and the proposed air pollution control equipment;

(E) An estimate of the fixed capital cost of the replacements and

of constructing a comparable entirely new potroom group;

(F) The estimated life of the existing potroom group after the

replacements; and

(G) A discussion of any economic or technical limitations the

potroom group may have in complying with the applicable standards of

performance after the proposed replacements.

(iii) The applicable regulatory authority will determine, within 30

days of the receipt of the notice required by paragraph (a)(2)(ii) of

this section and any additional information he/she may reasonably

require, whether the proposed replacement constitutes a reconstructed

potroom group.

(iv) The applicable regulatory authority's determination under

paragraph (a)(2)(iii) of this section shall be based on:

(A) The fixed capital cost of the replacements in comparison to the

fixed capital cost that would be required to construct a comparable

entirely new potroom group;

(B) The estimated life of the potroom group after the replacements

compared to the life of a comparable entirely new potroom group;

(C) The extent to which the components being replaced cause or

contribute to the emissions from the potroom group; and

(D) Any economic or technical limitations on compliance with

applicable standards of performance that are inherent in the proposed

replacements.

(b) Lower TF emission limit. The owner or operator shall calculate

a lower TF emission limit for any potline associated with the modified

potroom group, reconstructed potroom group, or new potroom group using

the following equation:

L1=f1 x LPG1 + (1-f1) x

LPL

Where

L1=the lower TF emission limit in kg/Mg (lb/ton);

f1=the fraction of the potline's total aluminum production

capacity that is cont

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