Proposed Requirements for Control Technology Determinations for Major Sources in Accordance With Clean Air Act (Act) Section 112(g)

ENVIRONMENTAL PROTECTION AGENCY

40 CFR Part 63

[FRL-5446-8]

Proposed Requirements for Control Technology Determinations for

Major Sources in Accordance With Clean Air Act (Act) Section 112(g)

AGENCY: Environmental Protection Agency (EPA).

ACTION: Notice of reopening of comment period; notice of availability

of draft rule.

SUMMARY: The EPA is reopening the comment period for the proposed rule

implementing section 112(g) of the Act and is announcing the

availability of a revised draft of the proposal. Section 112(g)

establishes requirements for owners or operators who intend to

construct, reconstruct, or modify a major source of hazardous air

pollutants (HAP). When no emission standard has been promulgated under

section 112(d) of the Act, determinations concerning such sources must

be made on a case-by-case basis. Today's notice announces the

availability of a revised draft of the proposed rule which implements

section 112(g)(2)(B) of the Act with respect to constructed or

reconstructed major sources, and requests comment on the revised draft.

The EPA does not intend at this time to issue a rule implementing the

provisions of section 112(g) which concern modifications.

DATES: The revised draft of the proposed rule will be available in the

public docket and on the EPA electronic bulletin board on the date this

document is signed. Comments concerning this document or the revised

draft rule must be received by EPA on or before April 25, 1996.

ADDRESSES: The revised draft rule and other information pertaining to

the proposed rule are contained in Docket Number A-91-64. The docket is

available for public inspection and copying from 8:30 a.m. to 12:00

p.m. and 1:00 p.m. to 3:00 p.m., Monday through Friday, at the EPA's

Air Docket Section, Waterside Mall, Room M1500, EPA, 401 M Street,

Southwest, Washington, DC 20460. A reasonable fee may be charged for

copying. The draft rule is also available on the Office of Air Quality

Planning and Standards (OAQPS) electronic bulletin board, the

Technology Transfer Network (TTN), under Clean Air Act, Title III,

Recently Signed Rules. For information on how to access the TTN, please

call (919) 541-5384 between the hours of 1:00 p.m. and 5:00 p.m.

eastern standard time.

Comments concerning this notice or the revised draft rule should be

submitted (in duplicate if possible) to: Central Docket Section (6102),

EPA, Attn: Air Docket No. A-91-64, Washington, DC 20460.

FOR FURTHER INFORMATION CONTACT: Ms. Gerri Pomerantz, telephone (919)

541-2371, or Ms. Kathy Kaufman, telephone (919) 541-0102, Information

Transfer and Program Integration Division (MD-12), OAQPS, EPA, Research

Triangle Park, NC, 27711.

SUPPLEMENTARY INFORMATION: The information in this notice is organized

as follows:

I. Background and Major Differences between the Proposed Rule and

Draft Final Rule

II. Definition of ``Construct a Major Source''

III. Review of Applications for a maximum achievable control

technology (MACT) Determination

IV. Extensions of Compliance Date for Subsequent Emission Standards

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I. Background and Major Differences Between the Proposed Rule and

Draft Final Rule

In designing a program to implement MACT requirements under section

112(g), the EPA is guided by the need to balance several, often

competing, goals. Given a complex statutory mandate, the EPA has the

difficult task of designing a rule that is simultaneously

environmentally protective, maintains consistency across Agency

programs, minimizes the administrative burden on sources and States,

provides flexibility to sources, and maintains enforceability--yet is

not overly complex. The EPA's task is to create a coherent regulatory

whole that strikes the right balance among a broad set of goals.

Section 112(g) is primarily a transitional program designed to

operate until MACT standards issued under section 112(d) are in effect

for all categories of major sources of HAP. To date, the EPA has issued

17 MACT standards covering 29 categories of major sources of HAP

emissions, and has proposed five additional MACT standards covering 18

source categories. The EPA is currently developing all of the MACT

standards that are due to be completed in 1997, as well as several of

the standards due to be completed in 2000.

The EPA has concluded that the greatest benefits to be derived from

section 112(g) would be from the control of major source construction

and reconstruction in the period before these MACT standards go into

effect. Therefore the EPA has determined that today's draft rule should

implement only that portion of section 112(g) which requires new source

MACT determinations for constructed and reconstructed major sources,

but not that portion which requires existing source MACT determinations

for modifications of existing sources. The EPA requests comment on this

approach.

Under this approach, sources of toxic air pollution will be

controlled at the time of construction or reconstruction, when controls

are most cost-effective to install. This is a major streamlining and

simplification step that will focus section 112(g) implementation where

it will provide the greatest reduction in emissions to the environment,

certainty to the regulated community, and reduce the overall

administrative burden on both regulators and the regulated community.

The EPA's decision to implement only the construction and

reconstruction provisions of section 112(g) is premised in part on the

Agency's ability to issue the remaining MACT standards under section

112(d) in a timely way, and also in part on the assumption that where

there are existing State air toxics programs that address

modifications, they will continue to operate as they do currently. If

there were substantial delays in issuance of MACT standards, or radical

changes to existing State programs, increased exposure to emissions

from unregulated sources of HAP could occur and threaten public health

and the environment. If such delays were to occur, the EPA would

reconsider whether to move forward to cover modifications under section

112(g).

The EPA believes that Congress's basic goal in adopting section

112(g) of the Act was to make use of the opportunity for environmental

protection that exists when major sources of HAP undergo changes that

would lead to significant emission increases. The opportunity to

evaluate emission control technologies, or other beneficial ways to

bring about environmental improvements, generally exists because the

environmental improvements are more efficient when built as part of the

initial design.

The EPA also recognizes that it is critical to the success of the

program to ensure that its provisions are enforceable and provide the

greatest possible incentive for compliance. At the same time, the EPA

recognizes the need to minimize administrative delays and grant sources

and permitting authorities the flexibility to seek environmentally

beneficial alternative means of control.

Finally, the program must be as consistent as possible with other

Federal air pollution control programs, and must be simple enough to

ensure smooth implementation. Today's draft rule eliminates much of the

complexity inherent in the portion of section 112(g) which covers

modifications to existing sources. Among other things, under this

simpler approach, it will not be necessary to proceed with development

of de minimis emission values or the hazard ranking system necessary to

support offset determinations. It will also not be necessary to address

the multitude of issues and concerns, raised in the proposed rule,

associated with defining the types of operations that would be

considered ``modifications.''

II. Definition of ``Construct a Major Source''

Today's draft rule does require additional discussion to clarify

the conditions under which a stationary source would require a new

source MACT determination; i.e., what criteria must be met for new

equipment to be considered construction or reconstruction of a major

source. The new equipment which would meet these criteria is referred

to as the ``affected source.'' The EPA intends that either a major

source constructed on a greenfield site, or a new major-emitting

stationary source with a discrete function at an existing plant site,

such as a new discrete process or production unit, should be considered

construction of a major source, and thus require a new source MACT

determination. The stationary source must also itself be inherently

major-emitting; the EPA does not intend that a new process unit causing

increased emissions at another unit downstream should be covered by

today's draft rule. The EPA requests comment on this overall approach.

Figure (1) illustrates how the definition of ``construct a major

source'' works.

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If the stationary source is constructed on a greenfield site and is

major-emitting, then the stationary source is an affected source under

section 112(g), and must apply new source MACT. If the stationary

source is being constructed at an existing plant site, then several

other criteria will determine whether it is to be considered an

affected source under section 112(g), and must apply new source MACT.

Box (i) (the box labels refer back to the sections of the

``construct a major source'' definition in the draft rule) asks: Will

the stationary source be controlled by existing emission control

equipment which the permitting authority has determined represents one

of the best technologies for control of HAP? If a new source can be

incorporated into such existing control technology without any

reduction in the degree of control of HAP, the new source would not be

considered ``construction'' under section 112(g)(2)(B). The state

permitting authority will be responsible for determining whether these

criteria apply, using those procedures it deems most appropriate.

The general purpose of this exclusion from the definition of

``construct a major source'' is to assure that facilities which have

previously installed good control equipment with presently unutilized

capacity will not be precluded from fully utilizing such equipment by

any marginal differences in control effectiveness between such

equipment and that required by new source MACT. Existing controls

should be deemed satisfactory only where they are representative of the

best technologies presently in use and the addition of new sources to

existing control equipment will not impair its overall effectiveness.

The rule also explicitly recognizes that some facilities have

previously installed such controls to comply with a best available

control technology (BACT) determination (that controls the HAP emitted

by the stationary source) under the prevention of significant

deterioration (PSD) program, a lowest-achievable emission rate (LAER)

determination under the new source review (NSR) program, or a toxics-

best available control technology (T-BACT) determination under a State

or local air toxics control program. The EPA requests comment on this

exclusion.

The EPA notes that the definition of a ``green-field site'' in the

draft rule includes developed sites which do not presently emit major

source quantities of HAP. EPA therefore requests comment concerning

whether the exclusion for new sources that use existing emission

controls should be applied to area sources that are within the

definition of a ``green-field site.''

Box (ii) asks: Is the new stationary source an integral component

of a larger process or production unit? If the source is a discrete

process unit or production unit as defined in the rule, and emissions

from the source exceed the major source threshold, it meets the

definition of an ``affected source'' under section 112(g) and is

subject to new source MACT control. The EPA requests comment on this

exclusion.

What does it mean to be an integral component of a larger process

or production unit? Today's rule defines ``integral component of a

larger process or production unit'' to be a stationary source or group

of stationary sources whose function, and the function of the process

unit or production unit, are interdependent. In other words, the

stationary source is the kind of component upon which the functioning

of the process or production unit relies, and vice versa. Equipment

which is an integral component of a process or production unit is part

of the functioning of the overall process or production unit. Under the

proposed definition, equipment which is not an integral component

itself comprises a process or production unit.

The EPA acknowledges that there is some room for judgment in

determining if a stationary source is an integral component of a larger

unit. Each individual determination should be based on answers to the

following questions: Is the new stationary source a component critical

to the function of the larger process or production unit? Could the

stationary source stand alone as an individually functioning unit if

constructed elsewhere? Could the stationary source be reasonably

controlled independently of the larger process? Reference documents

such as AP-42 1 describe examples of different groupings of

stationary sources that should be considered to be separately-

controlled processes, as well as those stationary sources, contained

within such processes, which should be considered integral components.

Examples in these reference documents, where relevant, should be used

to define a process or production unit.

\1\ U.S. EPA, AP-42, ``Compilation of Air Pollutant Emission

Factors,'' 5. ed., January 1995.

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The following examples should help illustrate where section 112(g)

should and should not apply. The EPA requests comment on these

examples.

1. An electronics manufacturing facility replaces individual

manufacturing equipment such as etching, plating, or photolithography

equipment with next generation etching, plating or photolithography

equipment. This equipment change would not trigger section 112(g),

because the individual etching or plating or photolithography equipment

is the kind of component upon which the functioning of the larger

production process relies. Therefore the function of the new stationary

source (the new etching, plating, or photolithography equipment) and

the larger production process are interdependent.

2. An aluminum reduction plant has several potlines. Each potline

consists of many pots, which are controlled using a common dry

scrubbing system. The company replaces a few pots on each line. This

equipment change would not trigger section 112(g), because the

individual pots are the kind of component upon which the functioning of

the larger production process relies. Therefore the function of the new

stationary source (the new pots) and the larger production process are

interdependent.

3. A chemical plant builds a new distillation column, to be added

to a series of distillation columns, the emissions from which are

collected at the end of the series and vented to a carbon absorber.

This equipment change would not trigger section 112(g), because the

individual distillation columns are the kind of component upon which

the functioning of the larger production process relies. Therefore the

function of the new stationary source (the new distillation column) and

the larger production process are interdependent.

4. A composites manufacturer adds additional vacuum and/or in-mold

coating capability to an existing mold, in order to improve surface

quality. This equipment change would not trigger section 112(g),

because the additional components of the mold are the kind of

components upon which the functioning of the larger production process

relies. Therefore the function of the new stationary source (the new

components of the mold) and the larger production process are

interdependent.

5. A glass manufacturer adds a new glass furnace and associated

process line which will emit HAPs in amounts above the major source

threshold. This is an example of a stationary source which is not an

integral component of a process or production unit, because it is

itself a production or process unit. Therefore the new furnace meets

the definition of ``affected source'' under section 112(g) and should

be controlled with new source MACT.

6. A composites manufacturer adds a new large molding line which

will emit

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HAPs in amounts above the major source threshold. This is an example of

a stationary source which is not an integral component of a process or

production unit, because the molding line is itself a separately

functioning process unit. Therefore the molding line meets the

definition of ``affected source'' under section 112(g) and should be

controlled with new source MACT.

7. An auto parts manufacturer adds a new automobile surface coating

line (i.e., from body shop to trim shop) which will emit HAPs in

amounts above the major source threshold. This is an example of a

stationary source which is not an integral component of a process or

production unit, because the line is itself a separately functioning

process unit, as described in AP-42. Therefore the coating line meets

the definition of ``affected source'' under section 112(g) and should

be controlled with new source MACT.

8. An existing chemical plant builds a new nitric acid plant onsite

which will emit HAPs in amounts above the major source threshold. This

is an example of a stationary source or group of stationary sources

which is not an integral component of a process or production unit.

Therefore the nitric acid plant meets the definition of ``affected

source'' under section 112(g) and should be controlled with new source

MACT.

9. A manufacturer replaces an entire process which is similar to an

entire process as it is described in AP-42. This is an example of a

stationary source or group of stationary sources which is not an

integral component of a process or production unit. Therefore the

process meets the definition of ``affected source'' under section

112(g) and should be controlled with new source MACT, provided that it

will emit HAPs in amounts above the major source threshold.

III. Review of Applications for a MACT Determination

Today's draft rule contains three options for preconstruction

review procedures for constructed and reconstructed major sources. The

permitting authority has discretion to prescribe those procedures to be

used in making a case-by-case MACT determination for constructed or

reconstructed major sources (except that the owner or operator of the

source may elect to use the part 70 or part 71 permitting process). The

proposed rule allowed use of either the part 70 or 71 permitting

process or a process, described in the proposed rule and in today's

draft rule, culminating in issuance of a ``Notice of MACT Approval.''

Today's draft rule adds one more option, designed to provide

flexibility to the permitting authority and the source. Proposed

section 63.43(c)(2)(ii) provides that if a permitting authority

establishes, or has already established, preconstruction review

procedures for sources to follow, then these procedures may be used in

lieu of any procedures prescribed by today's draft rule. The permitting

authority's prescribed procedures may have been developed for other

purposes beyond implementation of section 112(g), so long as they

provide for public participation in the case-by-case MACT determination

and ensure that a final MACT determination will be made prior to

construction or reconstruction. The draft rule also provides that a

final case-by-case MACT determination issued pursuant to any of these

procedures will be deemed federally enforceable. The permitting

authority need not obtain delegation under 40 CFR Part 63 subpart E in

order to adopt its own review procedures for a case-by-case MACT

determination. The EPA requests comment on this new provision.

The EPA also requests comment specifically on the presumption, in

section 63.43(d)(iv), that the constructed or reconstructed major

source should comply with the emission limitation set out in a relevant

proposed MACT standard or presumptive MACT determination made by the

EPA. The EPA believes that sources would be well-advised to comply with

such emission limitations, as those limitations would be most likely to

be consistent with the requirements of the eventual MACT standard.

IV. Extensions of Compliance Date for Subsequent Emission Standards

The EPA anticipates that new source MACT requirements adopted with

respect to construction or reconstruction of a particular source under

section 112(g)(2)(B) will normally be at least as stringent as any

subsequent requirements for existing sources adopted as part of a MACT

standard issued under section 112(d). However, should a subsequently

promulgated MACT standard impose more stringent requirements, EPA

believes that it may be appropriate in some instances for EPA to

establish a later compliance date for those sources which have acted in

reliance on a prior case-by-case MACT determination. The draft rule

expressly provides that EPA may establish separate compliance dates for

facilities which have notified EPA of such determinations in a timely

manner. Specifically, EPA may establish, in the MACT standard, a later

compliance date for those sources which have installed controls

pursuant to section 112(g), and have provided the EPA with data on

their section 112(g) control determination by the end of the public

comment period on the subsequent Federal standard.

The EPA requests comment on this approach, and on whether such

sources should be required to inform EPA, before proposal of the

subsequent MACT standard, that they have installed section 112(g)

controls.

In those instances where the subsequent MACT standard does not

establish a compliance date for sources subject to a prior case-by-case

MACT determination, the present draft rule retains the provision from

the original proposal authorizing the permitting authority to grant up

to eight years of additional time for the affected source to comply

with the subsequent MACT standard. The EPA has previously explained

that the structure of section 112 as a whole supports such a

construction of section 112(g), and a source may also be afforded up to

8 years to comply with a MACT standard in instances where a prior

emission limitation has been established by permit under section

112(j). The EPA requests comment on these provisions and this

interpretation.

Dated: March 18, 1996.

Mary D. Nichols,

Assistant Administrator.

[FR Doc. 96-7277 Filed 3-25-96; 8:45 am]

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