National Emission Standards for Hazardous Air Pollutants and Control Techniques Guideline Document; Aerospace Manufacturing and Rework Facilities

SUMMARY: This action proposes several amendments to the national

emission standards for hazardous air pollutants (NESHAP) for aerospace

manufacturing and rework facilities promulgated in the Federal Register

on September 1, 1995 (60 FR 45948). This action proposes corrections to

several references in the rule; revisions and additions to definitions;

clarification of the applicability of the cleaning operations

standards; clarification of the applicability of the rule to space

vehicles; addition of standards for Type I chemical milling maskants;

revision of standards for new and existing sources using dry

particulate filters to control emissions from topcoat and primer

application and depainting operations; addition of a test method for

determining the filtration efficiency of dry particulate filters;

addition of an exemption for certain water-reducible coatings; addition

of an essential use exemption for cleaning solvents; clarification of

compliance dates; clarification of the applicability of new source MACT

to spray booth standards; clarification of the requirements for new and

existing primer and topcoat application operations; clarification of

monitoring requirements for dry particulate filter usage; addition of

appendix A to this subpart containing definitions for specialty

coatings; and addition of a cross reference to requirements in the

General Provisions in subpart A of part 63.

In addition, today's document announces the availability of a draft

CTG document for control of volatile organic compound (VOC) emissions

from aerospace manufacturing and rework facilities for public review

and comment. This document has been prepared to assist States in

analyzing and determining reasonably available control technology

(RACT) for stationary sources of VOC emissions located within ozone

national ambient air quality standard nonattainment areas.

DATES: Comments. Comments on these proposed changes and on the CTG must

be received on or before December 30, 1996.

ADDRESSES: Comments. Interested parties may submit written comments (in

duplicate, if possible) on the proposed changes to the NESHAP to: Air

and Radiation Docket and Information Center (6102), (LE-131),

Attention, Docket No. A-92-20, U.S. Environmental Protection Agency,

401 M Street, SW., Washington, DC 20460. Comments on the proposed

changes to the NESHAP may also be submitted electronically by sending

electronic mail (e-mail) to: [email protected]. Submit

comments regarding the draft CTG to Mr. James Szykman, Policy Planning

and Standards Group, Emission Standards Division (MD-13), U.S.

Environmental Protection Agency, Research Triangle Park, NC 27711.

Electronic comments must be submitted as an ASCII file avoiding the

use of special characters and any form of encryption. Comments will

also be accepted on diskette in WordPerfect 5.1 or ASCII file format.

All comments in electronic form must be identified by the docket number

A-92-20. No Confidential Business Information (CBI) should be submitted

through e-mail. Electronic comments may be filed online at many Federal

Depository Libraries.

Docket. Docket No. A-92-20, containing the proposed regulatory

text, proposed Method 319, and other materials related to this

rulemaking used in developing the NESHAP, is available for public

inspection and copying between 8:30 a.m. to noon, and from 1 and 3

p.m., Monday through Friday, at EPA's Air and Radiation Docket and

Information Center, Waterside Mall, Room M-1500, 401 M Street, SW.,

Washington, DC 20460; telephone (202) 260-7548. A reasonable fee may be

charged for copying. The docket for the CTG is available for public

inspection and copying at the Office of Air Quality Planning and

Standards, Research Triangle Park, NC 27711.

Control Techniques Guideline

Copies of the draft CTG may be obtained from the U.S. EPA Library

(MD-35), Research Triangle Park, NC 27711; telephone (919) 541-2777.

The proposed amendments, proposed Method 319, and CTG also are

available on the Technology Transfer Network (TTN), one of EPA's

electronic bulletin boards. The service is free, except for the cost of

a phone call. Dial (919) 541-5742 with a modem of up 14,400 baud per

second (BPS) If more information on the TTN is needed, call the HELP

line at (919) 541-5384.

FOR FURTHER INFORMATION CONTACT: For information concerning the

standards or the CTG, contact Mr. James Szykman, Policy Planning and

Standards Group, Emission Standards Division (MD-13), U.S.

Environmental Protection Agency, Research Triangle Park, NC 27711;

telephone (919) 541-2452.

SUPPLEMENTARY INFORMATION:

Regulated Entities.

Entities potentially regulated by this action are owners or

operators of facilities that are engaged, either in part or in whole,

in the manufacturing or rework of commercial, civil, or military

aerospace vehicles or components and that are major sources as defined

in Sec. 63.2. Regulated categories include:

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

Category Examples of regulated entities

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

Industry............................ Facilities which are major sources

of hazardous air pollutants and

manufacture, rework, or repair

aircraft such as airplanes,

helicopters, missiles, rockets,

and space vehicles.

Federal Government.................. Federal facilities which are major

sources of hazardous air

pollutants and manufacture,

rework, or repair aircraft such

as airplanes, helicopters,

missiles, rockets, and space

vehicles.

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

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

guide for readers regarding 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 [company, business, organization, etc.] is regulated by this

action, you should carefully examine the applicability criteria in

Sec. 63.741 of the NESHAP for aerospace manufacturing and rework

facilities promulgated in the Federal Register on September 1, 1995 (60

FR 45948).

The information presented below is organized as follows:

I. Background

II. Summary of and Rationale for Rule Changes

A. Corrections to References

B. Definitions

C. Cleaning Operations

D. Applicability to Space Vehicles

E. Standards for Type I Maskants

[[Page 55843]]

F. Test Method for Determining Filtration Efficiency

G. Standards for Dry Particulate Filters

H. Exemption for Waterborne Coatings

I. Essential Use Exemption for Cleaning Solvents

J. Compliance Dates

K. Requirements for New Affected Sources (Spray Booths)

L. Requirements for New and Existing Primer and Topcoat

Application Operations

M. Monitoring Requirements for Dry Particulate Filter Usage

N. Depainting Operations

O. Applicability of General Provisions

III. Control Techniques Guideline

IV. Administrative Requirements

A. Docket

B. Paperwork Reduction Act

C. Executive Order 12866

D. Regulatory Flexibility Act

E. Regulatory Review

F. Unfunded Mandates Act

I. Background

National emission standards for hazardous air pollutants for

aerospace manufacturing and rework facilities were proposed in the

Federal Register on June 6, 1994 (60 FR 29216). Public comments were

received regarding the standards and the final NESHAP was promulgated

in the Federal Register on September 1, 1995 (60 FR 45948). This action

proposes to amend Secs. 63.741, 63.742, 63.743, 63.744, 63.745, 63.746,

63.747, 63.749, 63.750, 63.751, 63.752 and 63.753 of subpart GG of 40

CFR part 63. These sections deal with applicability, definitions,

general standards, cleaning operations, topcoat and primer application

operations, depainting operations, chemical milling maskant application

operations, compliance dates and determinations, test methods and

procedures, monitoring requirements, recordkeeping requirements, and

reporting requirements.

II. Summary of and Rationale for Proposed Rule Changes

Table 1, Summary of Subpart GG of 40 CFR Part 63--National Emission

Standards for Aerospace Manufacturing and Rework Facilities, was

included as part of the preamble when the final rule was published in

the Federal Register. Because of the many proposed corrections,

revisions, and additions to the final rule reflected in this notice,

Table 1.--Summary of Subpart GG of 40 CFR Part 63--National Emission Standards for Aerospace Manufacturing and

Rework Facilities

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

Affected source Requirement Description

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

Aerospace Facilities......................... Applicability: General Information.......... This rule applies

to facilities

engaged in

original equipment

manufacture and/or

rework of

aerospace vehicles

components and

assemblies and

that are major

sources as defined

in 40 CFR part 63.

Specific

operations are

covered by the

rule. (63.741)

Estimated Number of Facilities.............. Over 2,800

facilities are

expected to be

affected by the

rule. Applicable

SIC codes include

3720, 3721, 3724,

3728, 3760, 3761,

3764, 3765, and

4581.

Permit Requirements......................... Major sources

required to obtain

operating permit

in State where

facility is

located according

to procedures in

40 CFR part 70 and

applicable State

regulations.

(63.741(d))

All Affected Sources......................... Standards................................... 1. Comply with Sec.

63.4 through Sec.

63.6 of the

General Provisions

of 40 CFR part 63,

subpart A, except

as provided in

Table 3.a

(63.743(a))

2. Submit a

startup, shutdown,

and malfunction

plan, except for

new sources or

filter systems

operated per

manufacturer's

instructions.

(63.743(b))

3. Obtain approval

to use control

device not listed

in this subpart.

(63.743(c))

4. Wastes subject

to RCRA are exempt

from the

requirements of

this subpart.

(63.741(e))

Compliance Dates............................ As provided for in

the General

Provisions, within

3 years after the

effective date for

existing sources

and no later than

the standards'

effective date or

upon startup, as

appropriate, for

new and

reconstructed

sources.

(63.749(a))

Test Methods and Procedures................. See individual

affected sources.

Also, comply with

Sec. 63.7 of the

General

Provisions.

(63.749 & 63.750)

Monitoring Requirements..................... See individual

affected sources.

Also, generally

same as in Sec.

63.8 (f) and (g)

of the General

Provisions.

(63.751 (e) and

(f))

Recordkeeping Requirements.................. Comply with certain

parts of Sec.

63.10 of the

General

Provisions.

(63.752(a))

Reporting Requirements...................... 1. See individual

affected sources.

Comply with

certain parts of

Sec. 63.9 and

Sec. 63.10 of the

General

Provisions, except

as specified in ).

2. Operating permit

application can be

used for initial

notification.

(63.753(a)(2))

Cleaning Operations.......................... Standards................................... Housekeeping

measures specified

for all cleaning

operations at a

facility subject

to this subpart,

except as provided

in Table 4.

Measures address

placing cleaning

solvent laden

cloth or paper in

closed containers,

storing fresh and

used cleaning

solvent in closed

containers, and

minimizing spills

during handling

and transfer.

(63.744(a))

Test Methods and Procedures................. See individual

affected sources.

Monitoring Requirements..................... See individual

affected sources.

Recordkeeping Requirements.................. The name and vapor

pressure of each

cleaning solvent,

and supporting

documentation.

(63.752(b)(1))

[[Page 55844]]

Hand-Wipe Cleaning Operations................ Standards................................... 1. Except for spray

gun and flush

cleaning, all HAP

or VOC hand-wipe

cleaning solvents

must meet a

composition

requirement, have

a vapor pressure

less than or equal

to 45 mm Hg at 20

deg.C, or meet the

requirements

specified in an

alternative

compliance plan

administered by

the permitting

authority and

approved under

Section 112(l) of

the Clean Air Act.

(63.744(b))

2. List of cleaning

operations exempt

from composition

and vapor pressure

requirements.

(63.744(e))

Test Methods and Procedures................. 1. Composition

determination

through

manufacturer's

data. (63.750(a))

2. Vapor pressure

determination

through readily

available sources

if single

component; ASTM E

260-85 and

composite vapor

pressure

determination

procedure for

multiple component

solvents.

(63.750(b))

Monitoring Requirements..................... None.

Recordkeeping Requirements.................. 1. If complying

with composition

requirements,

name, data/

calculations, and

annual volumes.

(63.752(b)(2))

2. If complying

with vapor

pressure limit,

the name, vapor

pressure, data/

calculations/test

results, and

monthly volumes.

(63.752(b)(3))

3. For noncompliant

cleaning solvents

used in exempt

operations,

monthly volumes by

operation, and

master list of

processes.

(63.752(b)(4))

Reporting Requirements...................... Semiannual

1. Noncompliant

cleaning solvent

usage.

(63.753(b)(1)(i))

2. New cleaning

solvents and vapor

pressure or

composition.

(63.753(b)(1)(ii))

3. Statement

certifying

everything is in

compliance.

(63.753(b)(1)(v))

Spray Gun Cleaning........................... Standards................................... 1. Use one of four

specified

techniques or an

equivalent.

(63.744(c))

2. For enclosed

spray gun

cleaners, repair

as soon as

practicable, but

within 15 days.

(63.744(c)(1)(ii))

Test Methods and Procedures................. None.

Monitoring Requirements..................... Visual inspection

for leaks at least

once per month.

(63.751(a))

Recordkeeping Requirements.................. Record all leaks,

including source

identification and

dates leaks found

and repaired.

(63.752(b)(5))

Reporting Requirements...................... Semiannual

1. Noncompliant

spray gun cleaning

method used.

(63.753(b)(1)(iii)

)

2. Leaks of

enclosed spray gun

cleaners not

repaired within 15

days of detection.

(63.753(b)(1)(iv))

3. Statement

certifying

everything is in

compliance.

(63.753(b)(1)(v))

Flush Cleaning............................... Standards................................... Operating

procedures specify

emptying into

enclosed

container,

collection system,

or equivalent.

(63.744(d))

Test Methods and Procedures................. None.

Monitoring Requirements..................... None.

Recordkeeping Requirements.................. None.

Reporting Requirements...................... Semiannual

Statement

certifying

everything is in

compliance.

(63.753(b)(1)(v))

Primer and Topcoat Application Operations.... Standards................................... Minimize spills

during handling

and transfer.

(63.745(b))

Uncontrolled

Primers

1. Organic HAP

content limit: 350

g/l (2.9 lb/gal)

(less water) as

applied.

(63.745(c)(1))

2. VOC content

limit: 350 g/l

(2.9 lb/gal) (less

water and exempt

solvents) as

applied.

(63.745(c)(2))

3. Achieve

compliance

through: (1) use

coatings below

content limits, or

(2) use monthly

volume-weighted

averaging to meet

content limits.

(63.745(e))

Uncontrolled

Topcoats

4. Organic HAP

content limit: 420

g/l (3.5 lb/

gal)(less water)

as applied.

(63.745(c)(3))

5. VOC content

limit: 420 g/l

(3.5 lb/gal) (less

water and exempt

solvents).

(63.745(c)(4)).

6. Achieve

compliance as in

3. above.

(63.745(e))

Controlled Primers

and Topcoats

7. If control

system is used,

must be designed

to capture and

control all

emissions from the

application

operation and must

achieve an overall

control efficiency

of at least 81%.

(63.745(d))

All Primers and

Topcoats

8. Specific

application

techniques must be

used. If

alternative is

sought, can only

be used if

emissions are less

than or equal to

HVLP or

electrostatic

spray application

techniques.

(63.745(f)(1))

9. All application

equipment must be

operated according

to manufacturer's

specifications,

company

procedures, or

locally specified

operating

procedures.

(63.745(f)(2))

[[Page 55845]]

10. Exemptions from

No. 8 above

provided for in

certain

situations.

(63.745(f)(3))

11. Operating

requirements for

the application of

primers or

topcoats that

contain inorganic

HAP, including

control with

either particulate

filters or

waterwash, and

shutdown if

operated outside

manufacturer's

specified limits.

(63.745(g) (1)

through (3))

12. Exemptions from

No. 11 provided

for certain

application

operations.

(63.745(g)(4))

Performance Test Periods and Tests.......... 1. For

``compliant''

coatings: each 30-

day period. For

``averaged''

coatings: each 30-

day period. For

``controlled''

coatings,

noncarbon

adsorber: three 1-

hour runs. For

``controlled''

coatings, carbon

adsorber: each

rolling material

balance period.

(63.749(d)(1))

2. Initial

performance test

for all control

devices to

demonstrate

compliance with

overall control

efficiency

requirement.

(63.749(e)(2))

Test Methods and Procedures................. 1. Organic HAP

level

determination

procedures.

(63.750 (c) and

(d))

2. VOC level

determination

procedures.

(63.750 (e) and

(f))

3. Overall control

efficiency of

carbon adsorber

system determined

using provided

procedures; for

other control

devices, determine

capture efficiency

and destruction

efficiency. For

capture

efficiency, use

Procedure T in

Appendix B to 40

CFR 52.741 for

total enclosures

and 40 CFR

52.741(a)(4)(iii)

procedures for all

other enclosures.

(63.750 (g) and

(h))

4. For alternative

application

methods, first

determine emission

levels for initial

30-day period or

five aircraft

using only HVLP or

electrostatic, or

a time period

specified by the

permitting agency.

Then use

alternative

application method

for period of time

necessary to coat

equivalent amount

of parts with same

coatings.

Alternative

application method

may be used when

emissions

generated during

the test period

are less than or

equal to the

emissions

generated during

the initial 30-day

period or five

aircraft. Dried

film thickness

must be within

specification for

initial 30-day

period or five

aircraft as

demonstrated under

actual production

conditions.

(63.750(i))

Monitoring Requirements..................... 1. Temperature

sensors with

continuous

recorders for

incinerators, and

install,

calibrate,

maintain, and

operate

temperature

monitors according

to manufacturer's

specifications.

Use CEMS as an

alternative.

(63.751(b))

2. Continuously

monitor pressure

drop across

filter; read and

record pressure

drop or water flow

rate through

waterwash once per

shift. (63.751(c))

Recordkeeping Requirements.................. 1. Name and VOC

content for all

primers and

topcoats. If

coating contains

exempt solvents,

calculate total

HAP content.

(63.752(c)(1))

2. For

``compliant''

coatings, organic

HAP and VOC

contents as

applied, data/

calculations or

Method 24 used to

determine them,

and monthly usage.

(63.752(c)(2))

3. For ``low-HAP/

VOC'' primers,

annual purchase

records, and data/

calculations or

Method 24 used to

determine H.

(63.752(c)(3))

4. For ``averaged''

coatings, monthly

values of VOC

content (Ha and

Ga), and data/

calculations or

Method 24 used to

calculate Ha and

Ga. (63.752(c)(4))

5. For

``controlled''

coatings

(incinerator),

overall control

efficiency and

incinerator

temperature(s).

(63.752(c)(5))

6. For

``controlled''

coatings (carbon

adsorber), overall

control efficiency

and length of

rolling period and

all supporting

data/calculations.

(63.752(c)(6))

7. Pressure drop

across filter or

water flow rate

through waterwash

once per shift,

and acceptable

limits. (63.752(d)

(1) through (3))

Reporting Requirements...................... Semiannual

1. All instances

where organic HAP/

VOC limits were

exceeded.

(63.753(c)(1) (i)

and (ii))

2. Control device

exceedances (out-

of-compliance).

(63.753(c)(1)

(iii), (iv), and

(v))

3. Periods when

operation not

immediately shut

down due to

pressure drop or

water flow rate

being outside

limits.

(63.753(c)(1)(vi))

4. Statement

certifying

everything is in

compliance.

(63.753(c)(vii))

Annual

5. Number of times

the pressure drop

or water flow rate

limits were

exceeded.

(63.753(c)(2))

[[Page 55846]]

Depainting Operations........................ Applicability............................... Applies to the

outer surface of

aerospace

vehicles. Does not

apply to parts or

units normally

removed. Fuselage,

wings, and

stabilizers always

covered. Radomes,

parts normally

removed are

exempt.

(63.746(a))

Standards................................... 1. Unless exempted,

no organic HAP are

to be emitted from

chemical strippers

or softeners.

(63.746(b)(1))

2. Minimize

inorganic HAP

emissions during

periods of

nonchemical based

equipment

malfunction.

(63.746(b)(2))

3. Use of organic

HAP material(s)

for spot stripping

and decal removal

limited to 190

pounds per

aircraft per year

for commercial

aircraft and 365

pounds per

aircraft per year

for military

aircraft.

(63.746(b)(3))

4. Operating

requirements for

depainting

operations

generating

airborne inorganic

HAP, including

control with

particulate

filters or

waterwash systems.

Mechanical and

hand sanding are

exempt.

(63.746(b)(4) and

(b)(5))

5. Nonexempt

organic HAP

emissions

controlled at 81%

efficiency for

systems installed

before effective

date. For newer

systems, control

at 95%.

(63.746(c))

Performance Test Periods and Tests.......... 1. For

demonstrating no

organic HAP

emissions: each 24-

hour period.

(63.749(f)(1))

2. For spot

stripping and

decal removal

usage limits: each

calendar year.

(63.749(f)(1))

3. Initial

performance test

for all control

devices to

demonstrate

compliance with

overall control

efficiency

requirement.

(63.749(f)(1),

(f)(2), and

(f)(3))

Test Methods and Procedures................. 1. Procedures

provided for

determining pounds

of organic HAP

material(s) used

for aircraft.

(63.750(j))

2. Overall control

efficiency of

carbon adsorber

system determined

using specified

procedures; for

other control

devices, determine

capture efficiency

and destruction

efficiency. For

capture

efficiency, use

Procedure T in

Appendix B to 40

CFR 52.741 for

total enclosures

and 40 CFR

52.741(a)(4)(iii)

procedures for all

other enclosures.

(63.750(g) and

(h))

Monitoring Requirements..................... Continuously

monitor pressure

drop across

filter; read and

record pressure

drop or water flow

rate through

waterwash once per

shift. (63.751(d))

Recordkeeping Requirements.................. 1. Name and monthly

usage (weight) of

all organic HAP

material(s) used

in chemical

strippers.

(63.752(e)(1))

2. For controlled

chemical strippers

(carbon adsorber),

overall control

efficiency and

length of rolling

period and all

supporting data/

calculations.

(63.752(e)(2))

3. For controlled

chemical strippers

(other control

devices), overall

control efficiency

and supporting

documentation.

(63.752(e)(3))

4. List of parts/

assemblies

normally removed.

(63.752(e)(4))

5. For nonchemical

based equipment,

name and type, and

malfunction

information

including dates,

description, and

alternative

methods used.

(63.752(e)(5))

6. For spot

stripping and

decal removal,

annual volume

used, annual

average volume per

aircraft, and all

data/calculations

used to calculate

volume per

aircraft.

(63.752(e)(6))

7. Pressure drop

across filter or

water flow rate

through waterwash

once per shift and

acceptable limits.

(63.752(e)(7))

Reporting Requirements...................... Semiannual

1. 24-hour periods

where organic HAP

were emitted from

depainting

operations in

violation of rule.

(63.753(d)(1)(i))

2. New and

reformulated

chemical strippers

and HAP contents.

(63.753(d)(1)(ii),

(iii), and (iv))

3. New non-chemical

based depainting

techniques.

(63.753(d)(1)(v))

4. Malfunction

information on non-

chemical based

techniques

including dates,

description, and

alternative

methods used.

(63.753(d)(1)(vi))

5. Periods when

operation not

immediately shut

down due to

pressure drop or

water flow rate

being outside

limits.

(63.753(d)(1)(vii)

)

6. List of new/

discontinued

aircraft models

and, for new

models, list of

parts normally

removed for

depainting.

(63.753(d)(1)(viii

))

7. Organic HAP

control device

exceedances.

(63.753(d)(3))

8. Statement

certifying

everything is in

compliance.

(63.753(d)(1)(ix))

Annual

9. Exceedances of

average annual

volume limits for

spot stripping and

decal removal.

(63.753(d)(2)(i))

[[Page 55847]]

10. Number of times

the pressure drop

or water flow rate

limits were

exceeded.

(63.753(d)(2)(ii))

Applicability............................... Applies only to

chemical milling

maskant operations

with Type I or II

chemical milling

maskants.

(63.747(a))

Standards................................... Minimize spills

during handling

and transfer.

(63.747(b))

Uncontrolled

Maskants

1. Organic HAP

emissions: 622 g/l

(5.2 lb/gal) (less

water) as applied

for Type I, 160 g/l

(1.3 lb/gal) (less

water) as applied

for Type II.

(63.747(c)(1))

2. VOC emissions:

622 g/l (5.2 lb/

gal) (less water

and exempt

solvents) as

applied for Type

I, 160

g/l (1.3 lb/gal)

(less water and

exempt solvents)

as applied for

Type II.

(63.747(c)(2))

3. Achieve

compliance

through: (1) use

maskants below

content limits, or

(2) use monthly

volume-weighted

averaging to meet

content limits.

(63.747(e))

Controlled Maskants

4. If control

device is used,

system must be

designed to

capture and

control all

emissions from

maskant operation

and must achieve

an overall control

efficiency of at

least 81% for

systems installed

before effective

date. For newer

systems, control

at 95%.

(63.747(d))

Performance Test Periods and Tests.......... 1. For compliant

maskants: each 30-

day period. For

averaged maskants:

each 30-day

period. For

controlled

coatings, carbon

adsorber: each

rolling period.

For controlled

coatings,

noncarbon

adsorber: three 1-

hour runs.

(63.749(h)(1))

2. Initial

performance test

required for all

control devices to

demonstrate

compliance with

overall control

efficiency

requirement.

(63.749(h)(2) and

(h)(3))

Test Methods and Procedures................. Procedures provided

essentially

identical to those

for primers and

topcoats for

organic HAP and

VOC content

levels.

(63.750(g), (h),

and (l)-(o))

Monitoring Requirements..................... Same as for primers

and topcoats if

incinerators are

used. (63.751(b))

Recordkeeping Requirements.................. Same as for primers

and topcoats.

(63.752(f))

Reporting Requirements...................... Semiannual

1. Exceedances of

organic HAP/VOC

limits.

(63.753(e)(1), (2)

and (7))

2. Control device

exceedances (out

of compliance).

(63.753(e)(3))

3. New maskants.

(63.753(e)(4))

4. New control

devices.

(63.753(e)(5))

5. Everything is in

compliance.

(63.753(e)(6))

Waste Handling and Storage Operations........ Standards................................... Minimize spills

during handling

and transfer.

(63.748)

Test Methods and Procedures................. None.

Monitoring Requirements..................... None.

Recordkeeping Requirements.................. None.

Reporting Requirements...................... None.

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

a The EPA promulgated regulations for subpart A of 40 CFR part 63, which were published in the Federal Register

on March 16, 1994 at 59 FR 12408.

Table 1 has been revised and is included as a reference summary of

the revised standards.

A. Corrections to References

In the promulgated rule, there were several references to

Sec. 63.751(b)(7), which only existed in an earlier draft of the

standard. The EPA proposes the following revisions:

Sec. 63.751(b)(6)(ii)(A) of the promulgated rule references

(b)(7)(iii)(A)(3), but should reference paragraph (b)(6)(iii)(A)(2);

Sec. 63.751(b)(6)(iii) references (b)(7)(iii)(A), and (b)(7)(iii) (B)

or (C), but should reference paragraphs (b)(6)(iii)(A), and (b)(6)(iii)

(B) or (C); Sec. 63.751(b)(6)(iii)(A)(2) references (b)(7)(iii)(A)(1),

but should reference paragraph (b)(6)(iii)(A)(1);

Sec. 63.751(b)(6)(iii)(D) references (b)(7)(iii) (B) or (C), but should

reference paragraph (b)(6)(iii) (B) or (C).

B. Definitions

The EPA proposes that several definitions should be added to

Sec. 63.742 and several should be revised, based on additional

information submitted to the Agency after promulgation of the final

rule. The EPA proposes to clarify the definition of cleaning solvent

because many aqueous cleaners may contain negligible amounts of HAP and

VOC. In the promulgated rule, the definition of cleaning solvent states

that cleaning solvents do not include ``solutions that contain no HAP

and VOC.'' The EPA proposes revising the definition as follows:

Cleaning solvent means a liquid material used for hand-wipe,

spray gun, or flush cleaning. This definition does not include

solutions that contain HAP or VOC below the de minimis levels

specified in Sec. 63.741(f) (e.g., water or acetone).

Based on additional information received from industry, the EPA

proposes to change the definition of aircraft transparency. As

promulgated, the definition is limited to the aircraft windshield. On a

fighter aircraft, the windshield is only one component of the entire

canopy. On a commercial aircraft, passenger windows are constructed of

similar transparent materials as those used for the windshield. Also,

many aircraft transparencies are not laminated, but are monolithic

transparent materials.

[[Page 55848]]

The EPA proposes the following definition for aircraft transparency:

Aircraft transparency means the aircraft windshield, canopy,

passenger windows, lenses, and other components that are constructed

of transparent materials.

The Agency proposes to add a new definition of closed-cycle

depainting system as follows:

Closed-cycle depainting system means a dust free, automated

process that removes permanent coating in small sections at a time,

and maintains a continuous vacuum around the area(s) being depainted

to capture emissions.

The Agency is proposing this definition and is proposing an exemption

from the total enclosure requirements found in Sec. 63.746(b) for users

of this emerging technology that encloses the area to be depainted and

maintains a vacuum to capture all emissions. Captured emissions are

then separated/filtered/treated and the resulting solid waste material

is then appropriately disposed.

With these proposed requirements, the Agency intends to provide

owners or operators of affected sources with the flexibility to use

this emerging technology for depainting operations, while not

penalizing the owner or operator by requiring the unnecessary enclosure

of the vehicle or component being depainted.

The EPA proposes to change the definition of high volume low

pressure (HVLP) spray equipment as follows:

High volume low pressure (HVLP) spray equipment means spray

equipment that is used to apply coating by means of a spray gun that

operates at 10.0 psig of atomizing air pressure or less at the air

cap.

This change eliminates the 100 psig fluid delivery pressure specified

in the final rule, since new technology has demonstrated that this

requirement does not have to be met in order to ensure adequate

transfer efficiency.

The EPA also proposes adding a definition of waterborne (water-

reducible) coating as follows:

Waterborne (water-reducible) coating means any coating that

contains more than 5 percent water by weight as applied in its

volatile fraction.

The Agency has added and used this definition to encourage the use

of water-reducible coatings (i.e., coatings that inherently result in

lower organic HAP and VOC emissions). See Section H for additional

information on exemption(s) of waterborne coatings.

The Agency also proposes adding a definition for antique aerospace

vehicle or component so that these vehicles and components may be

exempted from the regulation. It was never the Agency's intent to

require compliance for rework operations associated with antique

aerospace vehicles or components including vintage aircraft or

historical museum collections. The Agency agrees with members of the

general aviation community that antique aerospace vehicles or

components (i.e., aerospace vehicles or components more than 30 years

old) present significant compliance challenges. Among these challenges

are the difficulties in obtaining modifications to maintenance

specifications (required if changes in coating or depainting operations

are to be made) from manufacturing companies that are frequently no

longer in operation. Another factor is the historical significance of

maintaining the original integrity of the vehicle or component. In

exempting these vehicles and components, the Agency proposes to adopt

the definition of antique aircraft as defined in 14 CFR part 45 and

limit the scope of this exemption to those vehicles or components that

are not routinely in commercial service in the capacity for which they

were designed. The Agency's intent in limiting this exemption is to

require compliance for aerospace vehicles or components that may meet

the age requirement but are still in routine commercial or military

operation. The Agency also notes that this exemption would not apply to

an airframe that may be more than 30 years old, but has been rebuilt

and is still in routine commercial or military service in the capacity

for which it was originally built.

The EPA also proposes revising the definition of specialty coating

by adding a sentence that states, ``Individual specialty coatings are

defined in appendix A to this subpart and in the CTG for Aerospace

Manufacturing and Rework Operations.'' This addition will allow

affected owners or operators to easily identify which coatings are

considered specialty coatings and are therefore exempt from this

standard. The CTG also contains VOC limits for the specialty coatings

defined in appendix A; appendix B (now redesignated as appendix A to

this subpart) was referenced in Sec. 63.743(a) of the final rule, but

inadvertently omitted from the Federal Register publication of the

final rule.

In appendix A to this subpart, the EPA proposes to revise the last

sentence of the definition of adhesive bonding primer to state, ``There

are two categories of adhesive bonding primers: primers with a design

cure at 250 deg.F or below, and primers with a design cure above

250 deg.F.'' This revision is a clarification that was omitted in the

final rule.

C. Cleaning Operations

Under the promulgated rule, the standards for cleaning operations

could be read to apply to all cleaning operations at a facility, not

only to cleaning operations that involve aerospace vehicles,

components, or coating equipment. In order to clarify the applicability

of the standards for cleaning operations, the Agency proposes to limit

the applicability of the final rule only to the manufacture or rework

of aerospace vehicles or components. Other, non-aerospace activities

are not subject to the requirements of this rule.

However, the owner or operator of a facility is not restricted from

voluntarily extending to other operations the use of cleaning solvents

which comply with the requirements of these NESHAP, where it is

determined that such use is technologically feasible. For example, it

might simplify purchasing, recordkeeping, or employee training, if the

same hand-wipe cleaning solvents are used for several or all operations

at a facility.

The EPA proposes replacing the word ``solvent'' with the defined

term ``cleaning solvent'' for clarity and consistency in Sec. 63.744,

paragraphs (a), (b), (c), and (e).

The EPA also proposes a change to the cleaning rag storage

requirement. The EPA proposes rewording the first sentence of

Sec. 63.744(a)(1) as follows:

Place cleaning solvent-laden cloth, paper, or any other

absorbent applicators used for cleaning in bags or other closed

containers upon completing their use.

The promulgated NESHAP requires that cleaning rags be stored

immediately after use. The word ``immediately'' is being removed from

the sentence to make the rule more consistent from a temporal

standpoint with the storage requirements contained in the California

SIP-approved rules that were the basis for this requirement.

Section 63.744(a)(1) of the promulgated rule also requires subject

facilities to ``[u]se bags and containers of such design so as to

contain vapors of the cleaning solvent.'' It has been brought to the

Agency's attention that a literal interpretation of this language means

100 percent capture efficiency, and even the most effective rag storage

containers currently in use in the industry do not guarantee 100

percent capture of cleaning solvent vapors. The Agency did not intend

such a literal interpretation of this requirement. The quoted language

is intended to be implemented as a work practice standard, not as an

absolute prohibition on emissions from rag containers. An

[[Page 55849]]

example of the type of container contemplated by this language would be

a rigid container constructed of impermeable material and using a

tight-fitting lid, such as a 55-gallon drum with a fitted lid. Such a

container would satisfy this requirement even though it cannot

guarantee 100-percent capture efficiency.

In addition, the EPA proposes changing the requirements for flush

cleaning to cover the situation where an operator is cleaning multiple

items at the same station, without leaving the station. The proposed

change to Sec. 63.744(d) is as follows: ``* * * empty the used cleaning

solvent each time aerospace parts or assemblies, or components of a

coating unit (with the exception of spray guns) are flush cleaned * *

*.'' This change will better address the Agency's intent in regulating

flush cleaning.

Based on information from industry, the EPA proposes a modification

to the exemption in Sec. 63.744(e)(10). This exemption was intended to

address windshield and canopy cleaning; however, many of the older

canopies in service are constructed of acrylic, rather than

polycarbonate. The Agency notes that acrylic canopies have the same

critical cleaning requirements as the polycarbonate canopies, and

believes that they therefore fall within this exemption as follows:

Cleaning of aircraft transparencies, polycarbonate, or glass

substrates.

D. Applicability to Space Vehicles

Space vehicles (i.e., vehicles designed to travel beyond the limit

of the earth's atmosphere) are specifically exempted from the

requirements of this rule, except for the standards for depainting

operations. The EPA proposes removing the reference to these vehicles

in Sec. 63.741(f) and adding an additional specific exemption in a new

paragraph, Sec. 63.741(h), to clarify the exemption. The EPA proposes

Sec. 63.741(h) as follows:

Regulated activities associated with space vehicles designed to

travel beyond the limit of the earth's atmosphere, including but not

limited to satellites, space stations, and the Space Shuttle System

(including orbiter, external tanks, and solid rocket boosters), are

exempt from the requirements of this subpart, except for depainting

operations found in Sec. 63.746.

E. Standards for Type I Maskants

The EPA proposes to establish an emission limitation for Type I

maskants and to include Type I maskants within the definition of

chemical milling maskants.

Pursuant to section 114 of the Clean Air Act (Act), information

regarding maskants was requested from nine companies that own or

operate aerospace manufacturing and rework facilities. Information was

requested for all types of maskants, including total quantity used,

formulation data, VOC and organic HAP content as received and as

applied, substrate category and the composition of the metal alloy on

which the maskant is applied, a listing of the type of parts or

specific aircraft surfaces on which the maskant is used, VOC and HAP

emissions from maskant application operations, and type(s) of controls

(if any). The information received on Type I maskants was used to

calculate a MACT floor. The MACT floor was determined to be the

weighted (by usage volume) average HAP emissions from the sources, 622

grams per liter [g/L] (5.2 pounds per gallon [lb/gal]).

The EPA proposes revising Sec. 63.747(c) to include organic HAP and

VOC content limits of 622 g/L (5.2 lb/gal) as the standard for

uncontrolled Type I chemical milling maskants. The EPA proposes

revising paragraphs (c)(1) and (2) to specify that the organic HAP and

VOC limits of 160 g/L (1.3 lb/gal) apply only to Type II chemical

milling maskants.

Due to the proposed addition of a standard for Type I chemical

milling maskants, EPA also proposes removing the definition of Type I

maskants from the list of specialty coatings in appendix A of this

subpart and revising the definition for chemical milling maskant in

Sec. 63.742 of the promulgated rule to read as follows:

Chemical milling maskant means a coating that is applied

directly to aluminum components to protect surface areas when

chemical milling the component with a Type I or Type II etchant.

This does not include bonding maskants, line sealers, and critical

use and seal coat maskants. Additionally, maskants that must be used

on an individual part or subassembly with a combination of Type I or

Type II etchants and any of the above types of maskants (e.g.,

bonding, line sealers, and critical use and seal coat) are also

exempt from this subpart.

The EPA also proposes revising the definition for chemical milling

maskant application operations in Sec. 63.742 to ``application of

chemical milling maskant for use with Type I or Type II chemical

milling etchants.'' The EPA specifically requests comments on the

development of the MACT floor for Type I chemical milling maskants

(Docket No. A-92-20).

F. Test Method for Determining Filtration Efficiency

The Agency is proposing a test method, test Method 319, for the

determination of filtration efficiency for paint overspray arrestors

(also referred to as particulate filters). The Agency is proposing that

this method be used by filter manufacturers to certify the efficiency

of their filters for meeting the dry particulate filter requirements

also being proposed in today's amendments.

The filter efficiency tables (Tables 1, 2, 3, and 4 of Sec. 63.745)

were developed from testing conducted in November, 1995 to determine

the fractional filtration efficiency of high efficiency two- and three-

stage, liquid- and solid-phase particulate filters, also referred to as

paint overspray arrestors. The tests also developed a filtration

efficiency test method for use in certifying filters to be used by

owners or operators in complying with the aerospace NESHAP.

The EPA specifically requests comments on the proposed test method

for certifying the filtration efficiency for these dry particulate

filters.

G. Standards for Dry Particulate Filters

The Agency is proposing revised MACT requirements for the control

of inorganic particulates from certain primer, topcoat, and depainting

operations. Pursuant to section 114 of the Act, information regarding

particulate filters was requested from nine companies that own or

operate aerospace manufacturing and rework facilities. Information was

requested for all types of particulate filters, including filter

manufacturer, manufacturer's part number, number of stages, type of

operation being controlled (topcoat or primer operation, dry media

blasting operation, or other), installation date, filter construction/

structure/composition, and control efficiency (with supporting

information).

Table 1 of Sec. 63.745 Two-Stage Arrestor; Liquid Phase Challenge

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

Filtration efficiency requirement, Aerodynamic particle size range,

%

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

>90 >5.7

>50 >4.1

>10 >2.2

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

[[Page 55850]]

Table 2 of Sec. 63.745 Two-Stage Arrestor; Liquid Phase Challenge

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

Filtration efficiency requirement, Aerodynamic particle size range,

%

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

>90 >8.1

>50 >5.0

>10 >2.6

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

Table 3 of Sec. 63.745 Two-Stage Arrestor; Liquid Phase Challenge

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

Filtration efficiency requirement, Aerodynamic particle size range,

%

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

>95 >2.0

>80 >1.0

>65 >0.42

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

Table 4 of Sec. 63.745 Two-Stage Arrestor; Liquid Phase Challenge

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

Filtration efficiency requirement, Aerodynamic particle size range,

%

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

>95 >2.5

>85 >1.1

>75 >0.70

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

For topcoat and primer operations, information was received on 510

booths with particulate filter controls. For dry media blasting

(depainting) operations, information was received on 22 booths with

particulate filter controls. Based on a review of the available data,

the EPA proposes requiring existing sources using particulate filters

in depainting as well as topcoat and primer operations, in which any of

the coatings contain inorganic HAP, to meet the filtration efficiency

established for the two-stage system that was tested. Specifically, the

Agency proposes requiring owners or operators of existing sources to

use particulate filters that are certified by the filter manufacturer

to meet or exceed the efficiency data in Tables 1 and 2 of Sec. 63.745

(developed from the two-stage filter testing).

The Agency is also proposing that new sources meet the filtration

efficiency data points for the three-stage system that was tested.

Specifically, the Agency proposes requiring owners or operators of new

sources to use particulate filters that are certified by the filter

manufacturer to meet or exceed the efficiency data in Tables 3 and 4 of

Sec. 63.745 (developed from the three-stage filter testing). The Agency

believes that proposed performance based control efficiency

requirements for particulate filters used in painting and depainting

operations will give owners and operators greater flexibility in

selecting their particulate filter system and will not preclude the use

of new, high-efficiency filtration technologies or very high efficiency

one-stage filters that may be developed in the future. The EPA

specifically requests comments on these proposed standards for

particulate filters used in topcoat and primer application and dry

media blasting (depainting) operations.

In announcing these revised MACT requirements for particulate

emissions, the Agency realizes that there are unique circumstances

where owners and operators who have commenced construction or

reconstruction of a new spray booth or hangar after the proposed

regulation and have had to comply with the requirements in the

promulgated rule. For these situations, the Agency has provided these

owners or operators of aerospace manufacturing or rework operations who

have commenced construction or reconstruction of new spray booth or

hanger for depainting operations, primer, or topcoat operations, in

which any of the coatings contain inorganic HAP's, prior to October 29,

1996 the flexibility to meet either the requirements of the promulgated

regulation or the proposed amendments to the final regulation found in

today's notice. Existing sources will be required to meet the

requirements for depainting operations and topcoat or primer

application operations found in the final amended rule.

H. Exemption for Waterborne Coatings

The EPA proposes that any waterborne coating for which the

manufacturer's supplied data demonstrate that the coating meets the

organic HAP and VOC content limits for its coating type as specified in

the regulation be exempt from many of the organic HAP and VOC related

requirements of this regulation. If the manufacturer's supplied data

indicate that the waterborne coating meets the organic HAP and VOC

content emission limits for its coating type, as specified in

Secs. 63.745(c) and 63.747(c), then the owner or operator would not be

required to demonstrate compliance for these coatings using the

procedures in Sec. 63.750(c). However, the owner or operator would

still be required to maintain purchase records and manufacturer's

supplied data sheets for exempt coatings. Owners or operators of

facilities using waterborne coatings would also be required to handle

and transfer these coatings in a manner that minimizes spills, apply

these coatings using one or more of the specified application

techniques, and comply with inorganic HAP emission requirements. This

exemption would be added as Sec. 63.741(i) as follows:

Any waterborne coating for which the manufacturer's supplied

data demonstrate that organic HAP and VOC contents are less than or

equal to the organic HAP and VOC content limits for its coating

type, as specified in Secs. 63.745(c) and 63.747(c), is exempt from

the following requirements of this subpart: Secs. 63.745(d)-(e),

63.747(d)-(e), 63.749(d) and (h), 63.750(c)-(h) and (k)-(m),

63.752(c) and (f), and 63.753(c) and (e). A facility shall maintain

the manufacturer's supplied data and annual purchase records for

each exempt waterborne coating readily available for inspection and

review, and shall retain these data for 5 years.

Section 63.741(f) would also be modified to include Sec. 63.741(i) in

the list of additional specific exemptions from regulatory coverage.

The EPA is proposing this exemption for waterborne coatings based

on settlement discussions with the two petitioners that filed for

review of the compliance demonstration provisions for waterborne

coatings in Sec. 63.750. The Agency is proposing this exemption to

streamline and simplify the requirements for owners and operators of

facilities using these coatings and to encourage the use of waterborne

coatings which may result in lower emissions than other coating types.

I. Essential Use Exemption for Cleaning Solvents

Under title VI of the Act and the Montreal Protocol, Essential Use

Waivers have been granted for limited applications of ozone depleting

compounds (ODC's). The EPA proposes that an essential use exemption be

added to this rule for cleaning operations that have been identified in

an Essential Use Waiver. The exemption would be added as

Sec. 63.744(e)(13) as follows:

Cleaning operations identified in an Essential Use Waiver which

has been reviewed and approved by the U. S. EPA and the voting

parties of the International Montreal Protocol Committee [sections

604(d)(1) and (g)(2) of the Act].

The EPA requests comments on this proposed essential use exemption.

J. Compliance Dates

The EPA wishes to clarify an inconsistency between the preamble to

the final rule and the regulation. The preamble to the final aerospace

NESHAP states, ``Owners or operators of new commercial, civil, or

military

[[Page 55851]]

aerospace OEM and rework operations with initial startup after

September 1, 1998 will be required to comply with all requirements upon

startup.'' This statement is incorrect. The text of the promulgated

regulation correctly states that new sources, with initial startup on

or after September 1, 1995, must comply with all requirements upon

startup. The EPA also proposes to clarify that the deadline for

approval of an alternate control device is 120 days prior to the

compliance date. This clarification, mistakenly omitted from the

published final rule, would be reflected in Sec. 63.743(c).

K. Requirements for New Affected Sources (Spray Booths)

The Agency wishes to clarify the requirements for new affected

sources. An affected source is an emission unit, process, or operation

identified in the NESHAP that is part of the entire facility, but is

not necessarily a major source. In today's proposal the Agency is

clarifying its intent that a spray booth or hangar that contains a

primer or topcoat application operation subject to Sec. 63.745(g) or a

depainting operation subject to Sec. 63.746(b)(4) is considered an

affected source and has added this description under Sec. 63.741(c). If

such an affected source is constructed or reconstructed after October

29, 1996 then that spray booth or hangar must comply with the

applicable inorganic control requirements. Construction or

reconstruction of a new spray booth or hangar at a facility for an

existing coating or depainting operation will not cause the existing

operation to be subject to any other new source standards; only the new

spray booth or hangar will be subject to the applicable new source

requirements for inorganic HAP and will need to comply upon the

effective date of the requirements or startup, whichever is later. The

EPA also proposes making this clarification in the final rule in

Sec. 63.749(a).

In addition, EPA wishes to clarify that Secs. 63.5(b)(3) and (4) of

the General Provisions, which require advance notice and approval by

the Agency prior to construction or reconstruction of a major affected

source, shall apply to the construction or reconstruction of a new

spray booth or hangar at a facility for an existing coating or

depainting operation only if the booth or hangar will constitute a

major source of inorganic HAP's. Owners or operators of an existing

coating or depainting operation who construct or reconstruct a new

booth or hangar which is not a major source of inorganic HAP's will

only be required to submit an annual notification on or before March 1

of each year. This annual notification shall include all of the

information required in Sec. 63.4(b)(4) for each such booth or hangar

constructed or reconstructed in the prior calendar year, except that

the information shall be limited to the inorganic HAP's from the new

booth or hangar. Of course, any owner or operator that constructs or

reconstructs a new spray booth or hangar at a facility at which there

is no existing coating or depainting operation will be required to

comply with all of the applicable notice and advance approval

requirements of Sec. 63.5.

L. Requirements for New and Existing Primer and Topcoat Application

Operations

Since promulgation, the Agency has received reports of confusion in

interpreting the applicability of primer and topcoat application

requirements to an industry that utilizes a plasma spray operation to

apply metallic coatings to a metallic substrate. In today's preamble,

the Agency notes that such a plasma spray operation is not subject to

the aerospace manufacture and rework NESHAP, but would rather be

addressed under the miscellaneous metal parts and products (surface

coating) NESHAP that is scheduled for promulgation in 2000.

The Agency has also provided additional flexibility to owners or

operators of primer and topcoat application operations seeking to use

alternative application methods. The promulgated NESHAP requires owners

or operators to use the alternative application method in production on

actual production parts or assemblies for a period of time sufficient

to coat an equivalent amount of parts and assemblies with coatings

identical to those used in an initial 30-day period. After this time

the actual organic HAP and VOC emissions shall be calculated for this

post-implementation period. The proposed amendments to the final NESHAP

allow owners or operators an alternative approach whereby the proposed

application method is tested against either HVLP or electrostatic spray

application methods in a laboratory or pilot production area, using

parts and coatings representative of the process(es) where the

alternative method is to be used. Under this alternative, the

laboratory test will use the same part configuration(s) and the same

number of parts for both the proposed method and the HVLP or

electrostatic spray application methods. The Agency has added this

alternative in response to comments received from industry indicating

that the original requirements would require actual production trials

that could result in ineffective application equipment being used on

actual production parts or assemblies.

M. Monitoring Requirements for Dry Particulate Filter Usage

The Agency proposes to clarify the monitoring requirements for

owners or operators of depainting and painting operations using dry

particulate filters and HEPA filters to comply with this NESHAP. The

final rule requires owners or operators to install and maintain devices

to continuously measure the pressure drop across the system. In this

proposal, the Agency continues to require owners or operators to

operate a device to continuously monitor this parameter at all times.

This requirement does not require an owner or operator to continuously

record the pressure drop. However, the Agency is adding language to

Sec. 63.751(c)(1) to clarify that owners or operators only are required

to read and record these pressure drop data once per shift.

N. Depainting Operations

Based on numerous comments on the depainting operation standard,

the EPA proposes a clarification to Sec. 63.746. The promulgated

standard was presented in terms of volume (gallons) of organic HAP-

containing chemical strippers per aircraft. Since the NESHAP is

specific to HAP, the EPA proposes changing the units of the standard

and stating the requirements in terms of weight (pounds) of organic HAP

materials per aircraft. The proposed standard is equivalent in terms of

actual HAP emissions to the atmosphere, but does allow greater

flexibility to the owner or operator of a new or existing depainting

operation in selecting materials to perform spot stripping and decal

removal.

The EPA proposes rewording Sec. 63.746(b)(3) as follows:

Each owner or operator of a new or existing depainting operation

complying with paragraph (b)(1) shall not, on an annual average

basis, use more than 190 pounds of organic HAP material(s) per

commercial aircraft depainted or more than 365 pounds of organic HAP

material(s) per military aircraft depainted for spot stripping and

decal removal.

Similarly, the EPA also proposes revising Equation 20 in

Sec. 63.750(j)(3) as follows:

[GRAPHIC] [TIFF OMITTED] TP29OC96.002

Where:

[[Page 55852]]

C=annual average weight (lb per aircraft) of organic HAP-material

(chemical stripper) used for spot stripping and decal removal.

m=number of organic HAPs contained in each chemical stripper, as

applied.

n=number of organic HAP-containing chemical strippers used in the

annual period.

Whi=weight fraction (expressed as a decimal) of each organic HAP

(i) contained in the chemical stripper, as applied, for each aircraft

depainted.

Dhi=density (lbs/gal) of each organic HAP (i) contained in the

chemical stripper, as applied, for each aircraft depainted.

Vsi=volume (gal) of organic HAP-containing chemical stripper i

used for during the annual period.

A=number of aircraft for which depainting operations began during the

annual period.

As further clarification, the promulgated standard for depainting

operations and the above proposed rewording are meant to allow

averaging in terms of annual usages of chemical strippers. For example,

if a facility depaints 10 aircraft in a given calendar year, the total

allowable amount of organic HAP material(s) would be 1,900 pounds per

year for commercial aircraft or 3,650 pounds per year for military

aircraft.

O. Applicability of General Provisions

The EPA proposes the addition of Table 1. General Provisions

Applicability to subpart GG, in order to clarify the applicability of

the General Provisions to this rule. Table 1 is referenced in

Sec. 63.741 and is located at the end of the final rule text.

III. Control Techniques Guideline

Under the Act, as amended in 1990, State implementation plans

(SIP's) for ozone nonattainment areas must be revised to require RACT

for control of VOC emissions from sources for which the EPA has already

published a CTG or for which it will publish a CTG between the date the

Amendments were enacted and the date an area achieves attainment status

(the Act, 182(b)(2)). The EPA has defined RACT as ``the lowest emission

limitation that a particular source is capable of meeting by the

application of control technology that is reasonably available

considering the technological and economic feasibility'' (44 FR 53761,

September 17, 1979).

The CTG's review current knowledge and data concerning the

technology and costs of various emissions control techniques. The CTG's

are intended to provide State and local air pollution authorities with

an information base for proceeding with their own analyses of RACT to

meet statutory requirements.

Each CTG contains a ``presumptive norm'' for RACT for a specific

source category, based on the EPA's evaluation of the capabilities and

problems general to the category. Where applicable, the EPA recommends

that States adopt requirements consistent with the presumptive norm.

However, the presumptive norm is only a recommendation. States may

choose to develop their own RACT requirements on a case-by-case basis,

considering the emission reductions needed to obtain achievement of the

national ambient air quality standards and the economic and technical

circumstances of the individual source.

This CTG addresses RACT for control of VOC emissions from aerospace

manufacturing and rework facilities. Volatile organic compound

emissions from primer, topcoat, and ``specialty'' coating application,

maskant application, sealing, adhesives, and cleaning operations are

addressed. Emission limits for processes also addressed in the NESHAP

are identical to the NESHAP limits. Many of the steps in these

operations involve the use of organic solvents and are sources of VOC

emissions. The sources, mechanisms, and control of these VOC emissions

are described in the CTG.

The EPA estimates that State and local regulations developed

pursuant to this draft CTG would affect about 2,869 facilities. Since

the only new requirements in the CTG (requirements that are not

included in the NESHAP) concern sealants, adhesives, and specialty

coatings, which represent only about 3 percent of all VOC emissions

from aerospace operations, the additional costs and emission reductions

resulting from the CTG will be negligible. Further information on costs

is presented in the draft CTG document and in the NESHAP for Aerospace

Manufacturing and Rework Facilities. The EPA requests comments from the

public on all aspects of the draft CTG.

IV. Administrative Requirements

A. Docket

The docket is an organized and complete file of all of the

information submitted to or otherwise considered by the EPA in the

development of this rulemaking. The docket is a dynamic file, since

material is added throughout the rulemaking development. The docketing

system is intended to allow members of the public and the industries

involved to readily identify and locate documents so that they can

effectively participate in the rulemaking process. Along with the

statement of basis and purpose of the proposed and promulgated

standards and the EPA responses to significant comments, the content of

the docket will serve as the record in case of judicial review (except

for interagency review materials) (Sec. 307(d)(7)(A) of the Act).

B. Paperwork Reduction Act

The information collection requirements contained in this proposed

amendment to a final rule have been submitted to the Office of

Management and Budget (OMB) for approval under the provisions of the

Paperwork Reduction Act, 44 U.S.C. 3501 et seq. An Information Request

Document has been prepared by the EPA and assigned ICR No. 1687.03. The

collection of information required by the proposed amendments to the

final rule has an estimated nationwide recordkeeping and reporting

burden of 829,500 hours ($29 million). This represents a 6 percent

reduction in the burden estimated for the final rule.

Send comments regarding any aspect of this collection of

information to Director, Regulatory Information Division, U. S.

Environmental Protection Agency (2136), 401 M Stree

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