National Emission Standards for Hazardous Air Pollutants for Source Categories: Aerospace Manufacturing and Rework; Reopening of the Public Comment Period

ENVIRONMENTAL PROTECTION AGENCY

40 CFR Part 63

[AD-FRL-5110-9]

RIN 2060-AE02

National Emission Standards for Hazardous Air Pollutants for

Source Categories: Aerospace Manufacturing and Rework; Reopening of the

Public Comment Period

AGENCY: Environmental Protection Agency (EPA).

ACTION: Reopening of the public comment period.

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

SUMMARY: On June 6, 1994, EPA proposed standards to regulate the

emissions of certain organic hazardous air pollutants from aerospace

manufacturing and rework facilities which are part of major sources

under Section 112 of the Clean Air Act as amended in 1990. The period

for receiving public comment on the proposed rule ended on September

15, 1994. This action announces the reopening of the comment period to

take comments on several amendments to the proposed rulemaking and

other issues raised during the original comment period; clarification

of the intent of a proposed requirement; and a correction of a

typographical error.

DATES: Comments: Comments must be received on or before January 6,

1995.

ADDRESSES: Comments: Comments should be submitted (in duplicate, if

possible) to: Air and Radiation Docket and Information Center (6102),

Attn: Docket No. A-92-20, U.S. Environmental Protection Agency, 401 M

Street SW, Washington, DC 20460. Docket: All information used in the

development of this action is contained or referenced in the preamble

below. Docket No. A-92-20 contains the supporting information for the

original NESHAP and is available for public inspection and copying

between 8:30 am and 5:00 pm, Monday through Friday, at the EPA's Air

and Radiation Docket and Information Center, Waterside Mall, Room M-

1500, 1st floor, 401 M Street SW, Washington, DC 20460, or by calling

(202) 260-7548 or FAX (202) 260-4400. A reasonable fee may be charged

for copying.

FOR FURTHER INFORMATION CONTACT: Ms. Mary Tom Kissell at (919) 541-

4516, Standards Development Branch, Emission Standards Division (MD-

13), U.S. Environmental Protection Agency, Research Triangle Park, NC

27711.

SUPPLEMENTARY INFORMATION:

I. Background

On June 6, 1994 (59 FR 29216), national emission standards for

hazardous air pollutants for the aerospace manufacturing and rework

source category were proposed. Since that time, the EPA has received

information on several aspects of the proposed rule which has led to

the amendments being proposed in this notice for the following sections

of the proposed subpart GG of 40 CFR part 63: Secs. 63.742, 63.745,

63.747, 63.749, 63.751, and 63.752. These sections deal with

definitions, standards for primer and topcoat application operations,

standards for chemical milling maskant application operations,

compliance determinations, monitoring requirements, and recordkeeping

requirements, respectively, for the NESHAP for aerospace manufacturing

and rework facilities. This notice announces the reopening of the

comment period for the aerospace NESHAP. However, only comments limited

to the subjects listed below will be considered.

(1) Correction of a typographical error regarding a request for

comments for commercial exterior primers;

(2) Proposal of a more stringent inorganic HAP emission control

requirement for new primer and topcoat application operations and

proposal of definition of high efficiency particulate air filter;

(3) Proposal to eliminate the exemption for chemical milling

maskant application operations for use with Type I chemical milling

etchants;

(4) Clarification of the intent of the proposed requirement for

control devices used to control emissions from coating application

operations;

(5) Proposal of reduced recordkeeping requirements to encourage the

use of a low VOC primer;

(6) Request for comment on depainting for private, corporate, and

small commuter aircraft;

(7) Request for comment on use and efficiency of control devices

for depainting operations using HAP-containing chemicals; and

(8) Request for comment on determining the appropriate length of

the rolling material balance period for liquid-liquid material balances

for carbon adsorbers used as control devices for solvent recovery

systems.

These actions are further discussed in Part III of this preamble.

As indicated in the preamble to the proposed rule at 59 FR 29217,

the EPA traditionally issues a draft CTG containing recommended control

levels for public comment. Rather than issue a separate draft CTG in

this case, the EPA used the notice of proposed rulemaking to request

public comment on draft best available control measures (BACM), which

is the same as the proposed maximum achievable control technology

(MACT) for coatings and solvents. Comments on the proposed rule and on

the proposed amendments in this document will also be considered in

formulating a final BACM.

The proposed regulatory text is not included in this Federal

Register notice, but is available in Docket No. A-92-20 or by written

or telephone request from the Air and Radiation Docket and Information

Center (see ADDRESSES). This notice with the proposed regulatory

language is also available on the Technology Transfer Network (TTN),

one of EPA's electronic bulletin boards. The TTN provides information

and technology exchange in various areas of air pollution control. The

service is free, except for the cost of a phone call. Dial (919) 541-

5742 for up to a 14,400 bps modem. If more information on TTN is

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

II. Summary of and Rationale for Changes to the Proposed Rule and

Request for Public Comments

A. Correction: Request for Comments on Commercial Exterior Primers

Section II.B.2.a of the preamble to the proposed rule requested

comments concerning whether the proposed organic HAP and VOC limits for

commercial exterior topcoats represents demonstrated technology. This

section should have referenced commercial exterior primers rather than

topcoats. Consequently, the specific paragraph in this section (see 59

FR 29224, middle column) should read as follows:

The EPA has received information indicating that the organic HAP

and VOC content limits for primers do not represent demonstrated

technology for exterior commercial primers. Consequently, the EPA is

soliciting comments on whether a separate category should be

developed for exterior commercial primers with organic HAP and VOC

content levels higher than the proposed levels for primers. These

comments should provide a technical justification for a higher

limit, including why currently available commercial primers cannot

be used by all sources.

B. Amendment: New Source Requirements for Inorganic HAP Emissions from

Coating Operations

The EPA has received information that at least one facility is

controlling inorganic HAP emissions from coating operations to a

greater degree than that required in the proposed rule. This facility

is using high efficiency particulate air (HEPA) filters in addition to

the filtration methods required in the proposed rule. Consequently, the

EPA is proposing that Sec. 63.745 require new primer and topcoat

application operations to use HEPA filters in addition to the

requirements specified in the rule proposed on June 6, 1994. Finally,

the EPA is proposing that these sources keep records of documentation

supplied by the filter manufacturer that the filter being used meets

the HEPA filter requirements specified in the definition in Sec. 63.742

being proposed by this notice.

C. Amendment: Inclusion of Chemical Milling Maskant Application

Operations for Use With Type I Chemical Milling Etchants

As proposed on June 6, 1994, the rule would apply only to those

chemical milling maskant application operations in which Type II

chemical milling etchants are subsequently used. This was based on

information the EPA received showing that no facilities had implemented

controls (either low VOC product substitutions or control devices) on

chemical milling maskant application operations for use with Type I

chemical milling etchants. Since proposal, the EPA has received comment

that there is at least one chemical milling maskant application

operation for use with Type I chemical milling etchants (which are not

currently covered in the proposed rule) with reduced organic HAP and

VOC content levels. The information supplied to the EPA, however, did

not detail the applicability of this chemical milling maskant to all

Type I etchant operations.

The MACT floor for chemical milling maskant application operations,

as determined by the average of the best performing 12 percent of

sources for which the EPA had emission information, included the use of

control devices (e.g., carbon adsorbers) as well as low organic HAP and

VOC content chemical milling maskants. As mentioned above, the

applicability of the low organic HAP and VOC content chemical milling

maskant for which the EPA received comment is unknown. However, the use

of the same control device technology as used for Type II chemical

milling operations is applicable to Type I chemical milling operations.

Consequently, the EPA is proposing to eliminate the exemption in

Sec. 63.747 for chemical milling maskants used with Type I etchants and

require them to meet the same requirements as chemical milling maskants

for use with Type II etchants. This will allow the use of any low

organic HAP and VOC content chemical milling maskant that meets the 160

grams per liter (1.3 pounds per gallon) organic HAP and VOC content

limits or the use of control devices as specified in the proposed rule.

D. Amendment: Requirement for the Capture of All Emissions by Control

Devices

The proposed rule required that whenever a control device is used

to meet the emission limitations specified, the owner or operator must

meet two provisions in order to demonstrate compliance. The first is

that the overall control efficiency, taking into account capture and

control efficiency, must be at least 81 percent. The second provision,

as specified in Secs. 63.745(c)(1), 63.747(d)(1), 63.749(d)(4)(ii)(A),

and 63.749(g)(3)(ii)(A) of the proposed rule, requires that all of the

emissions from the respective operations be captured and controlled by

the control device. In addition, the latter two paragraphs specify that

all emissions must be controlled other than ``incidental emissions that

may escape the capture system.''

The EPA has reviewed these provisions based on comments that have

been received concerning their enforceability. Based on this review,

the EPA has concluded that the provision specifying an overall control

efficiency is adequate to ensure application of MACT. The additional

language only added confusion to the proposed rule without any added

environmental benefit. The EPA, therefore, is deleting from the

proposed rule the four paragraphs referenced above concerning the

capture of all emissions from coating operations.

E. Amendment: Reduced Recordkeeping Requirements for Low Organic HAP

and VOC Content Primer

The EPA has received information that a low organic HAP and VOC

content (approximately 250 grams VOC per liter (2.1 pounds per gallon)

less water and exempt solvents) military waterborne primer has been

qualified according to military specification MIL-P-85582A, Type I,

Class II. While this primer may not represent demonstrated technology

for all types of uses, the EPA wishes to encourage the use of low

organic HAP and VOC content coatings. Consequently, the EPA is

proposing to amend the recordkeeping requirements of Sec. 63.752 of the

proposed rule to require that only annual purchasing records be

maintained on the use of any primer that contains a maximum of 250

grams organic HAP per liter (2.1 pounds per gallon) less water as

applied and 250 grams VOC per liter (2.1 pounds per gallon) less water

and exempt solvents as applied. This significantly reduces the

recordkeeping from the monthly records required for coatings with

higher organic HAP and VOC contents.

F. Request for Comments: Depainting Requirements for Private,

Corporate, and Small Commuter Aircraft

The EPA has received comments that the proposed standards for

depainting do not represent demonstrated technology for private,

corporate, and small commuter aircraft. Specifically, the commenters

stated that depainting of these aircraft cannot be accomplished through

the use of non-HAP chemical strippers or media blasting methods. One

commenter also stated that the physical characteristics of the coatings

typically used on the exterior of private and corporate aircraft cannot

be removed by the non-HAP chemical strippers currently on the market.

Another comment concerned the use of a control device, such as carbon

absorbers followed by a catalytic incinerator, to reduce emissions from

depainting operations where HAP-containing chemical strippers are used

as an alternative means of compliance.

In order to obtain additional and more specific information on this

sector of the aerospace rework industry, the EPA is requesting data and

information on the following specific issues:

1. One commenter stated that to achieve the finish quality demanded

by private and corporate aircraft purchasers, the aircraft

manufacturers are using coatings that have a cross-linked polymer

structure. According to the commenter, the structure of these coatings

does not allow the non-HAP chemical strippers to penetrate the coating

in order to break the bond between the coating and substrate. The EPA

requests information on whether non-HAP chemical strippers have been

shown to be effective on this type of coating. Commenters are requested

to provide as many details as possible of non-HAP chemical depainting

processes such as type and number of aircraft depainted, specific type

of primer and topcoats removed, VOC content (as applied, less water and

exempt solvents) of the primer and topcoat removed, and method of

disposal of the waste stripper. Information on the cross-linked polymer

coatings (e.g., VOC content, manufacturer) and its finish

characteristics are also requested.

In addition, the EPA requests comments on whether coatings other

than cross-linked polymers can be used on private and corporate

aircraft. Information requested includes: whether substitute coatings

can be used to achieve similar finishes; whether these other coatings

are easier to strip; VOC content (as applies, less water and exempt

solvents) of these other coatings; application methods; whether

changing coatings or not painting aircraft would affect aircraft

safety; and the economic impacts of changing coatings or not painting

aircraft.

2. Another commenter focused on the thin exterior skin panels of

private, corporate, and small commuter aircraft. The commenter said

that since weight is a critical parameter for these aircraft, very thin

exterior skin panels, that are very susceptible to damage from blast

depainting methods, are typically used. The commenter states that as a

consequence, no rework facilities are currently using blast depainting

methods on these aircraft.

Information on this topic is requested from any facility that has

evaluated or is currently using any blast depainting method or non-

chemical means to remove coatings from the exterior of private,

corporate, or small commuter aircraft. Specifically, the information

should document both successful and unsuccessful applications of blast

or mechanical depainting methods for these aircraft, or any other

aircraft with similarly thin exterior skin panels. Any information on

the generation and control of emissions from blast or mechanical

depainting operations (of any type of aircraft) would also be

beneficial.

G. Request for Comment: Control Devices for Depainting Operations Using

HAP-Containing Chemicals

Another commenter recommended that conventional chemical strippers

(containing HAPs) be allowed when emissions are reduced through the use

of a control device. The commenter stated that a combination of a

carbon adsorber and catalytic incinerator can achieve greater than 99

percent removal efficiency, and would be essentially equal to the

depainting standard of no HAP emissions.

Information submitted on this topic should address the feasibility

of installing such a control system, including cost and ability to

achieve greater than 99 percent removal efficiency on a dilute

airstream. Also, since some portion of the volatile HAP content of

conventional strippers will be retained in the waste sludge produced

from the operation, commenters should detail the ultimate fate of

emissions from the volatile HAPs in the waste stream. For example, a

conventional waste treatment system may aerate the waste stream as an

initial processing step, emitting the volatile HAPs at that point.

However, other waste treatment methods may destroy HAPs before the

aeration step. Comments are also requested on whether a standard

allowing the use of control devices to reduce emissions from depainting

operations should apply only to the depainting of private, corporate,

and small commuter aircraft, or if it should apply to military and

commercial aircraft as well.

H. Request for Comment: Appropriate Length of Rolling Material Balance

Period for Liquid-Liquid Material Balances for Carbon Adsorbers Used as

Control Devices on Solvent Recovery Systems

The EPA proposed Method 309, ``Method to Determine Length of

Rolling Period for Liquid/Liquid Material Balance Method'' to determine

the length of the rolling material balance period for the liquid-liquid

material balance for carbon adsorbers used as control devices on

solvent recovery systems. Several comments have been received

concerning whether Method 309 is the most appropriate method for the

aerospace industry in all instances. Therefore, the EPA is requesting

comment on alternatives to Method 309. Information in support of

alternatives to Method 309 should include how the length of the balance

period is determined; discussions of operations that make an alternate

determination of length appropriate; discussions concerning how

compliance is indicated and ensured with the alternative determination;

whether the alternative determination has been approved by state or

local air pollution agencies in permits or other documents; and why

Method 309 does not allow for the alternative determination.

III. Administrative Requirements

A. Paperwork Reduction Act

The changes detailed in this notice will have the following effects

on the information collection burden (recordkeeping, reporting, and

monitoring requirements) of the proposed rule:

(1) The request for comments concerning commercial exterior primers

does not affect the information collection burden of the proposed rule;

(2) New sources would be required to use HEPA filter and to

maintain records documenting that the filters used meet the

requirements of HEPA filters, but this would not significantly increase

the recordkeeping burden;

(3) The inclusion of Type I chemical milling maskants would require

the same recordkeeping and reporting requirements as specified for Type

II chemical milling maskants. Since the EPA has no information on which

to base an estimate of the number of facilities currently using Type I

chemical milling etchants, the magnitude of the effect on the

information collection burden cannot be made;

(4) The deletion of the requirement to capture and control all of

the emissions from coating operations does not affect the information

collection burden of the proposed rule; and

(5) Reducing the recordkeeping requirements for low organic HAP and

VOC content primers will result in a decrease in the information

collection requirements for those facilities that use these primers.

However, the EPA has no information on which to base an estimate of the

number of facilities that will use the low organic HAP and VOC content

primers. Therefore, the magnitude of the effect on the information

collection request burden cannot be made.

Even though the effect on the information collection burden cannot

be completely quantified, the EPA believes that it will not

significantly change. Therefore, the Information Collection Request

document developed for the proposed rule has not been revised.

B. Executive Order 12866 Review

This rule was classified as ``non-significant'' under Executive

Order 12866 and, therefore, was not reviewed by the Office of

Management and Budget.

List of Subjects in 40 CFR Part 63

Environmental protection, Air pollution control, Hazardous

substances, Reporting and recordkeeping requirements.

Dated: November 14, 1994.

Mary D. Nichols,

Assistant Administrator for Air and Radiation.

[FR Doc. 94-28842 Filed 11-21-94; 8:45 am]

BILLING CODE 6560-50-P